Engine mis-fires, hesitation from start, and poor fuel milage (hate to add another..) [Archive] - GrandAmGT.com Forum

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cgouch2
03-29-2007, 01:58 PM
All:

Hi I'm new here, and have been reading along many other threads regarding my same symptoms, but thought I'd throw my issues in the ring anyhow.

We just recently (fall) traded up our '98 Grand Prix for an '04 GrandAM GT 6 cyl, love the car, but.....

Since the late fall we began noticing a small lurch or 'miss' under slight load (up a small grade say or pulling away from a stop position), or just on flat surfaces at reduced RPM (due to overdrive gear etc....). The latter could be say 70KM/hr (maybe 1200-1400 RPM) or 95 - 100 KM/hr at 1800/1900 RPM. Not all the time, and naturally not repeatable when you are having someone look at it!! We've had it to the dealer countless times for this issue (10 - 12?)... a couple times they had indicated they had it working so poorly that they could hear the resulting problem in the exhaust. However, most times (the other 8 to 10 times) they simply returned the vehicle saying they couldn't duplicate the issue (and usually on the way home it would then do it for us again, very frustrating). Also of note the fuel mileage has bottomed out... we are lucky to get 350km (400 if VERY lucky) per 45 to 50L tank. This works out in imperial MPG to be about 20 to 25MPG (our GPrix for reference generally got 30MPG; 25 in winter/town and was bigger engine). The common things seem to be +/- 1500 RPM, outside temperature say from 0 C to +/- 5 C, and dampness/wet seems to be help the problem surface

There have been no codes tripped recently (the SES light was at one point before X-mas). The dealer provided us with a portable diag recorder, which we collected data when we felt the vehicle doing it's thing. No real codes, but they did pick up Torque Converter issues I guess... they replaced some sort of pressure solenoid, but that did not correct the issue. They did change the plugs, air filter (45000km, now about 51000) and indicated there was lots of spark etc. even though the plugs I guess were a bit fouled before changing (I suggested plug wires).

Long story short, they basically have exhausted their time to look into this for us unless it trips codes or becomes much worse. However, we are still feeling the problem, so there is still an issue. Also, during the real cold snap this winter (say -15c to -20c) I thought I could hear a small 'backfire' noise upon initial ignition from the tail pipes. This only seemed to happen in the extreme cold.

I have since had an independent mechanic look at it with his tester and knowledge as I really want this addressed. He used the tried-and-true method of checking plug wires and noted that in complete dark after moistened, he noted definite arching of fire from at least one wire, possibly two. Also, his tester didn’t generate any definite codes, but there were faults (misfires) reported on Cyl's 1 and 4 I believe he said.

He changed the plug wires for us, and after a week or so of driving and some damp weather has come back, the problem still persists.... ARG. Naturally the plug wires shouldn't have been arching, but that evidently wasn't the full solution as yet.

Where to go next? Coil? Fuel System? I think I read on here that the lay out of the Cyl-to-Coil indicated Cyl 1 and 4 went to one of the coils.

Also of note: the car is equipped with an after market remote start as well (I've seen this referenced here as well).

Any tips, sorry for the LENGTH!

cgouch2
03-29-2007, 02:01 PM
... can extended periods of bad plugwires etc. damage a coil?

drumking1721
03-29-2007, 02:04 PM
Idk about the coil so much....plugwires wont give the proper spark to the plug and may not fire right and all that good stuff

cgouch2
03-29-2007, 02:34 PM
Idk about the coil so much....plugwires wont give the proper spark to the plug and may not fire right and all that good stuff

.. So maybe a bad set of after market plugwires? If there was to be such a set, I'm sure I'd get them :-(

Thanks for the message,
Chris

gectek
03-29-2007, 03:26 PM
i would def look at the ignition control module and the coils and get a good set of wire looms to isolate the plug wires.

cgouch2
03-29-2007, 07:45 PM
i would def look at the ignition control module and the coils and get a good set of wire looms to isolate the plug wires.

Great, thanks for the message! Ignition control module which is under the coils good thought... while on the topic of 'ignition'... another symptom besides what I mention of the slight bogging out as you leave a stopped position, when you first start the vehicle, the engine surges a bit as it starts (somewhat normal), but then almost dies out before 'catching' and coming back to idle (doubtful this is normal). And, to top it off, it really doesn't appear to be idling high enough once it does stabilize itself. Also, things such as lights and defroster/blower fan are VERY dependent on this action... blower fan will blow stronger when accelerated, lights sorta dim out a bit as it's idling type thing... not bad, but more than I've witnessed in other vehicles. This, and of course the continued occasional herky-jerky feel when (what appears to be the mis-fire) traveling at 60 to 70 KM/hr (35-40 mph?).

For reference, when I start my Pursuit (G5), there is none of this engine rev, bog out, then back to idle... it snaps on, and goes to steady idle as it should. Granted, entirely different engine and 4 cyl etc etc, but still.

I beginning to doubt this is going to be found until either something breaks bad and/or the problem worsens and starts tripping codes.

Crank sensor??

drumking1721
03-29-2007, 09:34 PM
Sounds like the ignition

gectek
03-29-2007, 11:30 PM
werd...also look at fuel filter and maybe some good GM injector cleaner and do a top engine clean as well...should be a how to on the top engine clean thing. if u do look at coils and maybe find a bad one, i would go and replace the ICM as well and all the coils just to be safe and the MSD coils are actually cheaper than the others and are higher output. also make sure to use dielectric grease for all connections, both on the icm, plug wires, and the primary post that plugs in the bottom of the coil

cgouch2
03-30-2007, 11:40 AM
werd...also look at fuel filter and maybe some good GM injector cleaner and do a top engine clean as well...should be a how to on the top engine clean thing. if u do look at coils and maybe find a bad one, i would go and replace the ICM as well and all the coils just to be safe and the MSD coils are actually cheaper than the others and are higher output. also make sure to use dielectric grease for all connections, both on the icm, plug wires, and the primary post that plugs in the bottom of the coil

Thanks for all this useful advice! Very much appreciated. I do see there are few spots mentioned in Canada for MSD ignition supplies...

I have purchased GM Inj Cleaner, but haven't used it yet (been using the over the counter stuff a few times... every couple of tanks since Jan I guess once the dealer help started to go away...). At about 3 to 4 x the cost, I was waiting to see if the problems(s) could be better isolated before using it. I think I will end up using it anyhow at some point, but wanted to give the current guy some time to look into the problems with his scan tools etc. before adding anything more to the mix.

Another strange or odd question: would there be anything that anyone could think of that would actually be damaging the plug wires (overload, break them down, whatever...)? The reason I say this, when the new plug wires were put on, there was a few days that the car actually seemed to work ok (in fact I thought it may have even been fixed!), about 1 week later, we are back to the same issues. Just a thought (besides the wires themselves being bad from the beginning I mean), they were NAPA bought wires. The startup seemed better, the leaving from a stop seemed more responsive, idling seemed improved etc. , then now back to the same issues...

Can the wires be damaged by some underlying issue that we haven't isolated yet (in case we were to try another set ;-))?

Thanks

cgouch2
03-30-2007, 02:37 PM
Update: It appears after the guy has relooked at it, the replaced plug wires were arching more than the original ones replaced.... =8-o (DOH!) so we are deploying yet another set (what are the odds???). If these don't work for whatever reason, (unless something is blowing them out which I can't imagine what given the Voltage they should be normally capable of handling) I will have to explore and seek out a higher grade performance style brand if i can find some locally....

I will update on how this unfolds... :-)

cgouch2
04-04-2007, 02:38 PM
Well, a quick update. Plug wires were replaced again, coils were taken out, inspected/cleaned etc., plugs looked ok (a bit carboned maybe, but equally so)... the results are that the car is still acting up. Going to revisit the dealer again now that a few things have been tried on the side.

Leaning toward Ignition Control Module, Crank Senor, or Primary Computer (PCM?). It was spitting and sputtering quite bad at around 90km/hr for an extended highway drive a couple days ago when I had it out... hoping I can duplicate this when the dealer has a look again, though it does seem to go in cycles (or resets? hence the computer theory). Also, wife indicated that she was waiting at lights to pull across traffic to make turn... when she got her chance, the vehicle bogged and sputtered so bad she wasn't sure it was going to make the turn. Still has a problem by times pulling away from a stop position. However, today she indicated it only made that miss sensation maybe a time or two during her trip to work... getting VERY frustrated.

I can't imagine we got *2* bad sets of plug wires. I had a look after dark and there was no glowing or arching that I noticed on this set.

... anyhow... as they say, on it goes.

XtremeGaGt00
04-04-2007, 02:46 PM
i coulda sworn i had this problem before...and i THINK they replaced my MAP sensor...fixed the problem...dont take me up on that offer tho seriously...im not exactley forsure

NorKoastal
04-04-2007, 03:46 PM
Clean /Replace your MAF sensor..

This might be dirty and throwing off your RPM's and causing delayed throttle response... My Maf was routed through a ICCU unit and it did the same thing your talking about (cycling RPM's and delayed throttle response) when a wire slipped out of the connection pot.. After that I would Seafoam through the PCV tube, throw some in the oil and gas and test her out... Change the oil about a week after the sea foam was placed in the oil..

Good Luck..

cgouch2
04-05-2007, 08:56 AM
Ok, great, thanks for the new comments. Been doing some reading here and other places about MAS and it's related symptoms. Like 101-parts (:-)) that could be bad when you are experiencing this type of stuff, it certainly sounds like it could be it. It's just too bad it's not tripping any codes (that I'm aware of, no scan tool) or triggering SES lights etc.

The only time we had the SES light was when we had into shop one time for this same problem, but of all ironies and timing, the bearing assembly was replaced as well due to the ABS light etc. being on as well. When they reset the codes, naturally both sets of lights went off. Haven't seen the SES light since and they indicated it likely came on due to the other fault due to the ABS sensor/bearing issue (??!).

.... and, because it's and my car, with the luck I seem to be having, we are just over 50,000km, both bearings have been reportedly replaced between 40 and 45,000 km, there now is a new "swishing" (kinda' like rusty metal on rusty metal sound) sound coming from the front end again in rhythm with the speed of the wheel turning speed. Thought is may be brake/caliper holding on a bit or rotor issue, but had them taken off and checked and they appeared fine. The sounds appears to be closer to the RF/passenger side, but I'm not 100% convinced it's not a bit more toward the center of the vehicle now. Anyhow, something else for them to look at. It does seem to get a bit more noticeable under steering, and you can really only hear it at extreme slow speed (parking lots etc)... once at speed it either is a constant steady sound, or whatever, but it can't be distinguished... In some strange way, this couldn't be a worsening symptom of the poor engine performance could it (some component rotating and failing...)???

Geez... one problem at a time please :-(

NorKoastal
04-05-2007, 12:36 PM
Ok, great, thanks for the new comments. Been doing some reading here and other places about MAS and it's related symptoms. Like 101-parts (:-)) that could be bad when you are experiencing this type of stuff, it certainly sounds like it could be it. It's just too bad it's not tripping any codes (that I'm aware of, no scan tool) or triggering SES lights etc.

The only time we had the SES light was when we had into shop one time for this same problem, but of all ironies and timing, the bearing assembly was replaced as well due to the ABS light etc. being on as well. When they reset the codes, naturally both sets of lights went off. Haven't seen the SES light since and they indicated it likely came on due to the other fault due to the ABS sensor/bearing issue (??!).

.... and, because it's and my car, with the luck I seem to be having, we are just over 50,000km, both bearings have been reportedly replaced between 40 and 45,000 km, there now is a new "swishing" (kinda' like rusty metal on rusty metal sound) sound coming from the front end again in rhythm with the speed of the wheel turning speed. Thought is may be brake/caliper holding on a bit or rotor issue, but had them taken off and checked and they appeared fine. The sounds appears to be closer to the RF/passenger side, but I'm not 100% convinced it's not a bit more toward the center of the vehicle now. Anyhow, something else for them to look at. It does seem to get a bit more noticeable under steering, and you can really only hear it at extreme slow speed (parking lots etc)... once at speed it either is a constant steady sound, or whatever, but it can't be distinguished... In some strange way, this couldn't be a worsening symptom of the poor engine performance could it (some component rotating and failing...)???

Geez... one problem at a time please :-(

One thing that might be a culprit is a rubbind shied behind the front rotor.. Double check that the metal plate isn't scraping the inside of the rotor...

I would get the Air sensor area of the engine bay checked out.. Your air fuel mixture might be all goofed up if these sensors are dirty and throwing false reads.. Let us know how things go..

justinw
04-06-2007, 03:49 PM
I have the same problems as above on a 99' Alero. (fluctuating tach when started, hesitation on acceleration). New plugs and wires seemed to help somewhat, but only somewhat.

justinw
04-06-2007, 04:17 PM
This GM bulletin might apply (99-06-04-050). Not sure. GM techs?

The hesitation stumble is really bad at times.

gectek
04-06-2007, 11:50 PM
there are like 4 or 5 bulletins that may apply, most of them have to do with contamination of the MAF due to over oiling the filter, or a few other things. only way to know for sure is to take it to the dealer or try the testing and fixes yourself

cgouch2
04-07-2007, 01:24 PM
Sorry for being a bit stupid here, but 'over oiling the filter'.... this would be the Air Filter? I've had air filters changed on previous vehicles, and maybe I wasn't paying strict enough attention or doing it right, but I don't recall having one oiled before being installed... I could have sworn it was just a matter of going to parts store, buying the filter, opening the compartment and deploying the new one in place of the old...

Where does the 'over oiling' occur?

Man, I'm hoping it's something relatively simple like a grimed up MAF sensor... and not like bad compression in the motor or something.... =8-o Though I think my symptoms would be a lot worse... also plugs look ok and equal (though the gaps may be more than 0.060, but they were dealer replaced, so they should be correct).

I did forget to mention, the very first time the vehicle was in for this issue back in November I believe, the very first thing they did was change out the Air Filter, and they indicated to my wife that it was "chock block full" (this was a new to us car, and it was at about 44,000km at that time, we'd had it less than a month then). If the filter was that polluted, it's conceivable I suppose that contaminants have messed up the sensor behind it as a result??


As ALWAYS, I REALLY really appreciate the feedback, suggestions and responses from all of you.

PS: any info on the bullitens mentioned or the general info contained in them would be nice to read regarding this if someone has them....

cgouch2
04-07-2007, 01:26 PM
... had our oil changed today, and that appeared normal and fine, so more (good) information... I have been keeping an eye on the oil and coolant anyhow, but it was good to hear when it all came out during the change it still looked fine.

gectek
04-07-2007, 01:30 PM
well when i talk about over oiling it means an aftermarket gauze type filter like a KandN...but the paper filter u should have no prob. i would clean the MAF really good with some of the mass air flow cleaner u can get at the local parts store. if it is bad enough it has messed up the maf entirely and you have to get a new one. i would clean it first though. that sounds like the majority of the problem.

cgouch2
04-07-2007, 06:40 PM
well when i talk about over oiling it means an aftermarket gauze type filter like a KandN...but the paper filter u should have no prob. i would clean the MAF really good with some of the mass air flow cleaner u can get at the local parts store. if it is bad enough it has messed up the maf entirely and you have to get a new one. i would clean it first though. that sounds like the majority of the problem.

Ok cool. So, are they robust enough to clean or will that damage it? Naturally "be careful", but beyond the normal care, do you have to use EXTREME care or a certain method to clean?

Easy to get out, or is it a major (take to shop type) job? I suspect it would be almost the next thing behind the exit of the air filter chamber? Special process or trick to eject that out?

Is the sensor cleaner more or less like a brake cleaner or something different?

... and, sorry, one last, would this cause the engine to mis-fire, hesitate, and act like bad plugs/wires (what it feels a bit like still, depite all that replaced). Or just be bad on gas (which is also a sympton, but it's the periodic herky-jerkys at a constant speed or the bad hesitation from a stop that the annoying thing)

Thanks for your time and input.

zegoldfish
04-08-2007, 11:35 PM
A little different insight to the problem:
This sounds a lot like the problem I was having. Jumpy idle, delayed throttle response, boggy acceleration, etc. I replaced the plug wires and seemed to help temporarily. I sea-foamed the engine. Helped temporarily. I even replaced the LIM gasket (I was finding coolant in my oil and thought this might be contributing to the problem) but nothing seemed to actually fix the issue.

Then I remembered a friend of mine that had a 4Runner that was doing the same thing one night. When we finally got it home his catalytic converter was glowing red, indicating that it was clogged. He replaced the cat and everything was fine.
So after all that I had tried I finally got under my GA and gutted its cat. Lo-and-behold the catalytic converter was the problem. After gutting the cat the GA was running like a dream.

Its a long-shot, I know, but it could be worth looking in to.

justinw
04-09-2007, 09:49 AM
I think the above post might fix my problem. I'll check it out at night to see if it glows. :) (I really think it might be the problem - I replaced the engine in this alero - the other one burned oil really bad - I'm thinking it plugged up the converter. ) I'll post a week or so from now if replacing it works - It'll take me at least that long to find a cheap converter.

gectek
04-09-2007, 11:32 AM
look on here for the ones from magnaflow, they are good and not too expensive. high flow as well

zegoldfish
04-10-2007, 01:34 AM
I think the above post might fix my problem. I'll check it out at night to see if it glows. :) (I really think it might be the problem - I replaced the engine in this alero - the other one burned oil really bad - I'm thinking it plugged up the converter. ) I'll post a week or so from now if replacing it works - It'll take me at least that long to find a cheap converter.

Instead of going out and buying a cat to replace it, you could do what I did and gut it to make sure it's the source of the problem. Although if you live in a state where you have to pass emissions tests then you'd have to replace it anyway. :P Lucky for me Kentucky doesn't so I just gutted the cat and left it as is.

Or you could just disconnect the cat so you're just blowing out the exhaust manifold and drive it around the block (carefully) to see if the cat is the problem.

I know how aggravating it is to replace a part only to find out it wasn't the source of the problem.

justinw
04-10-2007, 08:25 AM
I bought an 18" section of 1 7/8 ID for $5 to use as a test tube. Plan is to weld it in place of the converter some time this week. If it fixes the problem, I'll buy a converter. The only problem is that it's going to throw the 02 sensor way off and possibly cause additional problems. Not sure how having a straight pipe instead of a converter would affect the 02 sensor....?

gectek
04-10-2007, 11:42 AM
it will not throw the pst cat O2 sensor off at all and cause problems because the post cat sensor has nothing to do with the engine controls, only the upstream. the downstream is a catalyst monitor only, nothing else. when the light goes on it means one of 2 things, bad sensor, bad cat...period

cgouch2
04-10-2007, 04:17 PM
“Pending fix”, as in the parts were replaced, everything seems to have normalized, so fingers are crossed.

Made my visit to the dealer today, and it was doing it's normal acting up, so I was confident the tech was at least going to feel the issue. He brought out the major scan tool (about the size of a small placemat :-)), and off for a drive we went... faults and codes were tripping nearly immediately as we left the parking lot. It was VERY sluggish leaving the dealer yard, so he was beginning to feel it right away.

... anyhow, long story short, it was throwing EGR valve codes. We stopped, he disconnected it for our return trip back to the dealer. It worked fine after that, so we figured we had it isolated. They replaced that part when we got back, took it for another spin, and the lines on the scan equipment were running in tandem with each other (good, on the previous drive, the lines were all erratic compared to what it 'wanted' to be driving at as the base line).

*fingers-crossed*, it has been running VERY smooth since this was replaced... so unless this was a weird coincidence, I'll say it's been fixed.

He did indicated (along with others that I have spoken to) that it's extremely odd and/or rare to have one fail or fault like that... they usually are on or the stick in a spot... not like this intermittent problem we were seeing.

Not sure why these codes/faults weren't seen until now, but they were obvious today. Very good pick up now from stop spot (puts the "GT" back into my car :-)) and hoping to see a small increase in fuel mileage now as well as a result.

Hope this can help some other out there as another testing item... (very simple to test in retrospect... a 30 sec disconnect under the hood.... man....)

Thanks for all the contributions... glad to see the community help each other so much… appreciate it.

justinw
04-10-2007, 06:49 PM
How much did it cost? I might want to try the dealer if working on the converter doesn't help. I'll pull the EGR valve plug for my trip home tonight, and see what happens...

cgouch2
04-10-2007, 06:53 PM
How much did it cost? I might want to try the dealer if working on the converter doesn't help. I'll pull the EGR valve plug for my trip home tonight, and see what happens...

Not sure how much it would have costed (I meant to ask, but they were busy and I forgot). Since mine is an '04, it's still under warranty in my case (for a few more months).

Let me know how you make out! As I say, this sounded very unusual to have that component fail out in this manner, but still worth a try.

Naturally I *wouldn't* run a long extended time without that connected (increased heat etc. and related damages?). A test though would be fine...

Interested to hear your results.

justinw
04-11-2007, 11:31 AM
You would or wouldn't go for a long time with the EGR disconnected?

I disconnected it for a 20 minute ride, but no luck. Same old hesitation, just as strong.

cgouch2
04-11-2007, 02:34 PM
You would or wouldn't go for a long time with the EGR disconnected?

I disconnected it for a 20 minute ride, but no luck. Same old hesitation, just as strong.

*wouldn't* - though he indicated for quick testing (a few miles etc.) shouldn't be any harm. Also, would depend somewhat on the outside temperature and how hot things were maybe? Not sure. Still exiting winter here, so temps are 5 deg C here +/- (35 +/- F?)

Anyhow, too bad that didn't help. Though, as he indicated, mine was unusual as it rarely (if ever?) fails like mine was (intermitantly)... it usual locks on or open or off type thing.

So far, it still seems to be OK for me.

cgouch2
04-11-2007, 02:36 PM
You would or wouldn't go for a long time with the EGR disconnected?

I disconnected it for a 20 minute ride, but no luck. Same old hesitation, just as strong.

thx, edited my previous message to correct that as well :nuts:

gectek
04-11-2007, 02:38 PM
u cant say all the time that when something fails like that it will go all or nothing

cgouch2
04-11-2007, 02:44 PM
u cant say all the time that when something fails like that it will go all or nothing

True. But I guess that would be the more common way for that part to fault out... stick on or stay off... type thing? Not sure.

Again, I really appreciate the help on here... thanks all.

cgouch2
04-11-2007, 02:54 PM
True. But I guess that would be the more common way for that part to fault out... stick on or stay off... type thing? Not sure.

Again, I really appreciate the help on here... thanks all.

-- actually more accurate may be to say "stick open" or "closed" rather than on/off. This part, once the temperature of vehicle comes up does what? Re-burns or re-cycles a portion of the exhaust to improve emissions and maybe nab any extra fuel particles that might be around as well (what few there may be)? It regulates a portion of this to be added to the clean air coming in (in whatever proportions the computer etc indicate at that time?) to be fired in the cyls?

Not sure, as should be apparent by now, I'm not a mechanic :-)

justinw
04-13-2007, 02:19 PM
New plugs, new wires, different MAP sensor, different ignition module, different EGR valve = still the same old problem

I decided to can the converter removal until I can test for possible backup of the exhaust system with a vacuum gauge connected to the UIM. We'll see.

gectek
04-13-2007, 02:22 PM
no...ull want the gauge that goes in where the upstream O2 sensor is...that will be the most acurate, if the reading is over 2.25 PSI then u have a bad cat

justinw
04-17-2007, 06:58 PM
Brought it in to the dealer - had a free tech2 check
-apparently the converter and o2 sensors are fine
-it looked like the MAF might be bad, replaced that, no fix
-different IAC, idle maybe fixed.
-new fuel filter

Hesitation is severe, not sure where to go next...

GTDriver
04-18-2007, 08:42 AM
Ok, great, thanks for the new comments. Been doing some reading here and other places about MAS and it's related symptoms. Like 101-parts (:-)) that could be bad when you are experiencing this type of stuff, it certainly sounds like it could be it. It's just too bad it's not tripping any codes (that I'm aware of, no scan tool) or triggering SES lights etc.

The only time we had the SES light was when we had into shop one time for this same problem, but of all ironies and timing, the bearing assembly was replaced as well due to the ABS light etc. being on as well. When they reset the codes, naturally both sets of lights went off. Haven't seen the SES light since and they indicated it likely came on due to the other fault due to the ABS sensor/bearing issue (??!).

.... and, because it's and my car, with the luck I seem to be having, we are just over 50,000km, both bearings have been reportedly replaced between 40 and 45,000 km, there now is a new "swishing" (kinda' like rusty metal on rusty metal sound) sound coming from the front end again in rhythm with the speed of the wheel turning speed. Thought is may be brake/caliper holding on a bit or rotor issue, but had them taken off and checked and they appeared fine. The sounds appears to be closer to the RF/passenger side, but I'm not 100% convinced it's not a bit more toward the center of the vehicle now. Anyhow, something else for them to look at. It does seem to get a bit more noticeable under steering, and you can really only hear it at extreme slow speed (parking lots etc)... once at speed it either is a constant steady sound, or whatever, but it can't be distinguished... In some strange way, this couldn't be a worsening symptom of the poor engine performance could it (some component rotating and failing...)???

Geez... one problem at a time please :-(
I have the same ruff noise problem in my 2002 Grand AM GT1. I think I have isolated the noise to tires, as when I increase tire pressure to 40psi the noise problem goes away. I have treid one tire at a time and could not isolate the tire if one is the specific cause. I have 83,000km on original tires anyways and will be buying a NEW set soon and will see if that was the real Problem of ruff noise sound at LOW Speed ONLY. I had dealer resurface New front Rotors and check bearings also and everything seems fine. They thought it might be a bearing but suggested to drive to see if it worsens and it has NOT worsened yet. Will be checking the suggestion on here of Back sheild plate though today to see if that might be the culprit..will Update ASAP.
Just wanted to comment also that the information on here is Priceless..GR88 Job members..Thanks

justinw
04-18-2007, 09:37 AM
Replaced the MAF, no difference. According to the tech, the converter is fine, so...

NorKoastal
04-18-2007, 11:23 AM
Brought it in to the dealer - had a free tech2 check
-apparently the converter and o2 sensors are fine
-it looked like the MAF might be bad, replaced that, no fix
-different IAC, idle maybe fixed.
-new fuel filter

Hesitation is severe, not sure where to go next...


Have the coil packs been replaced recently?? If not swapping a new one with the old set alternating location might help isolate a bad pack..

justinw
04-18-2007, 11:25 AM
I assume you mean the ignition module (thats what I call it - at the other end of the plugs.) Yes i switched it out with another one.

cgouch2
04-18-2007, 07:04 PM
I have the same ruff noise problem in my 2002 Grand AM GT1. I think I have isolated the noise to tires, as when I increase tire pressure to 40psi the noise problem goes away. I have treid one tire at a time and could not isolate the tire if one is the specific cause. I have 83,000km on original tires anyways and will be buying a NEW set soon and will see if that was the real Problem of ruff noise sound at LOW Speed ONLY. I had dealer resurface New front Rotors and check bearings also and everything seems fine. They thought it might be a bearing but suggested to drive to see if it worsens and it has NOT worsened yet. Will be checking the suggestion on here of Back sheild plate though today to see if that might be the culprit..will Update ASAP.
Just wanted to comment also that the information on here is Priceless..GR88 Job members..Thanks


Ok, I'd be curious about what you find. However, mine sounds more like a rusty-part-turning-in-(or on)-a-rusty-part sound. However, it is worse some days over others the more I get to drive the car lately (normally it's the wife's). I did up the pressures to 35 all around on Sunday past... we have one tire (on rear currently) that likely needs to come off, cleaned, re-rimmed and balanced as it drops pressure by 10+psi every couple weeks.

Back shield plate I'd be curious about though... and yes, I agree... information and this community is superb... thanks all!

GTDriver
04-18-2007, 07:20 PM
Ok, I'd be curious about what you find. However, mine sounds more like a rusty-part-turning-in-(or on)-a-rusty-part sound. However, it is worse some days over others the more I get to drive the car lately (normally it's the wife's). I did up the pressures to 35 all around on Sunday past... we have one tire (on rear currently) that likely needs to come off, cleaned, re-rimmed and balanced as it drops pressure by 10+psi every couple weeks.

Back shield plate I'd be curious about though... and yes, I agree... information and this community is superb... thanks all!

RE ruff Noise..that's the same sound I have like rust on rust. I was underneath it today changeing tranny fluid and fuel filter and inspected or looked for this backing plate on Front Rotors but failed to find plate there, I did look at back rotors also and found backing paltes on them....Now I know my front Rotors are fine cause they just where turned after Newly installed..back Rotors are originals (83,000km). I did NOTICE a lot of rust build up on INSIDE Face of Rotor and am wondering if that might be rubbing on Back Plate causeing this noise thats ONLY noticeable to my ear at low speeds and seems to increase also when tuning around corners. ( can't figure out how that would effect it on the back though lol).Just might take rear rotors off and knock off Ruff Outside edges to see if that makes a difference.......Laters
PS: the fuel filter change was a snap and Tranny fluid and filter was also..$$$ in Dah Pockets,,lol:applause:

justinw
04-19-2007, 05:50 PM
Looks like the LIM gasket is going bad... I'll fix that in a couple weeks and see if my problems go away.

justinw
04-23-2007, 08:58 AM
LIM gasket replaced, still no fix...

blk_grn_97GT
04-24-2007, 08:08 PM
about the guy and the cat converter, thats not going to fix the problem, converter don't just fail, there is underlying causes that melt cats especially a rich mix. also the guy with the egr, that is strange that it was intermittent but congrats, again usually it sticks open or closed or upper intake egr port is clogged which stuck closed you wouldn't notice besides emissions components are monitored by pcm which would throw a code, partially opened would definitely cause missfires cause egr valve only operated at cruise and decel, and also it doesn't burn recirculated exhaust gases, it merely takes up space in the combustion chamber cause you can't burn already burned gases.

justinw
04-24-2007, 09:10 PM
Well one of the codes that showed up was fuel system rich..

nate2023
04-25-2007, 12:21 AM
could be a fuel related issue then? or maybe even the O2 sensor sending for too much fuel, i forgot what color a spark plug turns when its too rich on fuel, i though green, i could be horribly wrong tho, all i know it a white spark plug (on the inside not the outside) means good air/fuel ratio.

Not sure if this helps

GTDriver
05-24-2007, 02:18 AM
Okay. I switched passenger tires around front to back and the NOISE that increased when turning LEFT is GONE now, but same rumble noise is there at Low speed. hence Bad Tire.

MassahP187
06-17-2007, 08:08 AM
I have been having the same problems with my 99 grand am SE with the hesitation especially from start up. After i start the vehicle, ill usually be backing out of my driveway and it hesitates to the point of almost stalling out (never actually stalls though). I didnt see it mentioned earlier, but when mine does this the "Low Trac" light comes on momentarily. Is anyone else with these issues getting that indicator light?

I was at a loss to know where to start diagnosing the problem, i thought it was a temp sensor somewhere since this only happens when the engine is cooled off. after it warms up it seems to run ok, somewhat loss of power upon accelerating, but thats all. it will work fine until the engine has time to cool again. Based on reading these posts, i am going to purchase a vacuum gauge and try to rule out any cat problems as well as clean the maf and see if that helps. Thanks for giving me a place to start for now!

armith
01-10-2008, 01:46 PM
I can't believe I didn't find this thread sooner.. BUMP...

I have been suffering with constant misfires, laggy acceleration from a stop, can hear the misses thru the exhaust.. Cold start it and put the car in gear within 30 (longer on cold days) seconds of starting it and it acts like it wants to stall then surges.. Basically I've been posting vicariously thru cgouch2. It all started back just before GAP 03 with the surging.. Then graduated up to misfires and eventually to all symptoms above. He're what I've done so far.

compression check @ around 120k tested good

plugs replaced @ 44k, 75k, 130k, 155k
wires replaced @ 44k, 130k, 155k
coil packs replaced @ 130k
ignition module replaced @155k
IAC replaced @100k
upper O2 sensor replaced @75k
LIM replaced @ don't exactly remember
stock MAF swap to rule out dirty MAF (borrowed from friend) @44k
put stock air intake with original air filter. 44k, 75k
100,000 mile full tune up. @105k
cleaners and additives to clear any blockages. @ regular intervals.

186k+ now and I'm running out of ideas. At this point I'm sure it'd be just passed off as "engine getting tired"

Injectors, EGR, MAP are all I can think of.. Of course I've let this problem persist for the last 120,000+ miles so I've gotten used to it. I like to think with it fastly approaching 200k and with the bruised quality history our cars have, I sometimes feel lucky that its made it this long and been as reliable as its been.

nate2023
01-11-2008, 02:53 PM
i had a similar problem for a while could not figure it out, it was throwing misfire codes randomly then i turned the corner and gave it a little gas and the tranny was slipping and the engine wouldn't go above 2k RPM, i pulled over and waited, after that it was back to normal but still hesitating. I checked my Tranny level and it was low, i added fluid and it hasn't came back since. Just trying to help.

drew_c14
01-12-2008, 08:13 AM
I can't believe I didn't find this thread sooner.. BUMP...

I have been suffering with constant misfires, laggy acceleration from a stop, can hear the misses thru the exhaust.. Cold start it and put the car in gear within 30 (longer on cold days) seconds of starting it and it acts like it wants to stall then surges.. Basically I've been posting vicariously thru cgouch2. It all started back just before GAP 03 with the surging.. Then graduated up to misfires and eventually to all symptoms above. He're what I've done so far.

compression check @ around 120k tested good

plugs replaced @ 44k, 75k, 130k, 155k
wires replaced @ 44k, 130k, 155k
coil packs replaced @ 130k
ignition module replaced @155k
IAC replaced @100k
upper O2 sensor replaced @75k
LIM replaced @ don't exactly remember
stock MAF swap to rule out dirty MAF (borrowed from friend) @44k
put stock air intake with original air filter. 44k, 75k
100,000 mile full tune up. @105k
cleaners and additives to clear any blockages. @ regular intervals.

186k+ now and I'm running out of ideas. At this point I'm sure it'd be just passed off as "engine getting tired"

Injectors, EGR, MAP are all I can think of.. Of course I've let this problem persist for the last 120,000+ miles so I've gotten used to it. I like to think with it fastly approaching 200k and with the bruised quality history our cars have, I sometimes feel lucky that its made it this long and been as reliable as its been.

Pull your upper manifold and check the resistance across the injectors. The book says to can do it at the PCM but because of the common ground it's not an accurate reading.
If you've changed everything you've said than I think your looking at a couple bad injectors or a knock sensor.
To test your EGR, take it off, which you have to do pull the upper manifold anyway so do this first. Find a piece of plastic or something to seal up the hole where the EGR mounts. Block it off and start the engine, if the engine runs better like this than replace the EGR.
I would also check for vacuum leaks, just take a propane torch, minus the flame of course, and spray propane anound all of the vacuum lines you can find while the engine is running. If the RPM's spike you found a leak.

gectek
01-13-2008, 07:08 PM
ya first off you dont have to take the intake off, just test at the wiring harness connector right by the alternator, second dont use propane, just squirt some carb cleaner around the intake for a vacuum leak.

drew_c14
01-13-2008, 08:50 PM
Carb cleaner is fine if you have a big leak and you know where to find it. Which would rather defeat the purpose of the test anyway. But if you're looking for a small leak, like the kind that would cause a lean misfire, they are usually much harder to find. You have to get a pretty goos sized amount of carb cleaner into the system to get the RPMs to change. It only takes a little propane.