Is this really a cracked engine block? [Archive] - GrandAmGT.com Forum

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MikeSilverGT
12-04-2008, 10:47 PM
Okay I've searched but the shop is giving me conflicting info... So my 2002 GAGT (52K miles) is leaking oil into the coolant, but NO coolant into the oil. The leak is very slow since my oil level isn't dropping much, but enough to gunk up my coolant every 6000 miles.

The shop used some dyes and still can't figure out where the leak is. I think it may be the LIM going out. They said that's possible, but aren't so sure because there's no coolant in the oil.

Here's where I get really worried, the tech at the shop thinks I may have a very small crack in the engine block causing this. He was going to call some engine shops for advice, but wants to pull the LIM to verify.

Any ideas or comments? It's getting old flushing the coolant every 6k miles, but I'd imagine replacing the engine block would suck as well.

Edit: Also the computer was throwing the P1189 code, which has to do with the oil pressure sensor, but never illuminated an idiot light.

cardude007617
12-04-2008, 10:57 PM
well you can def have an internal LIM leak. and its the worst kind cuz most people dont check their fluids on a regular basis. either way i would try to conserve miles on the car, cuz either way you put it, the oil and coolant are getting warn out faster than they should be and can/will eventually cause more sever engine damage than what you already may have.

any smoke or odors out of the exhaust?

MikeSilverGT
12-04-2008, 11:07 PM
Occasionally there is a very small puff of smoke when I start the engine, but otherwise I haven't noticed anything strange with the exhaust.
The oil does pretty well, but I change it often (syn Penzoil platinum every 3k).

I spooned some of the coolant into a white dish and it appeared to have oil streaks in it, but I wouldn't have guessed an oil leak as the dispstick stays pretty constant. Just the coolant tank filling up with peanut butter about every other oil change...

Also, the car doesn't run hot at all. There is a bit of bubbling from the coolant tank right after I turn it off though...

cardude007617
12-04-2008, 11:19 PM
idk, 3400s have pretty tough blocks... id doubt it would crack unless you overheated or something else... which you havent mentioned so all i can do is assume that nothing of that nature happened

350rs
12-04-2008, 11:24 PM
its a crack somewhere. no doubt about it. could just be in the head though. or just a head gasket. coolant IS getting into your crankcase. thats why your not noticing a level change. STOP DRIVING IT!! your causeing more damage than you know.. could be something as small as a LIM gasket. could be a head gasket. honestly i doubt its your block or head. do you run this thing hard and put it up wet? felpro has a problem solver gasket. when you do these gaskets be sure you replace the gaskets with these new ones. they are metal with a " rubber band" around the water jackets.

if i were you i would go ahead and do the head gaskets too. honestly it would only be a few more hours of work to change those when youve already got the full intake off. bring the heads to a reputable shop nearby to have them rebuild and decked. closely inspect the deck on your block for cracks when you clean it. pay close attention to thin areas. between cylinders, cylinder wall to water jacket. anything thin. use a magnifying glass if you have one. if anything looks suspicious. pull it out ( the engine..) and see if that same shop can do anything for it. it may be able to be sleeved. however, by the time you go through all those expenses you may be better off to get a new block.

haha i just noticed all the negativity in this post.. chances are its nothing more than the LIM gasket. good luck

cardude007617
12-04-2008, 11:31 PM
well the coolant in oil part screams LIM gasket... lets just hope for your wallet's sake, that all it is

AaronGTR
12-04-2008, 11:35 PM
It's hard to say. I can tell you this much... a failing LIM gasket usually causes coolant to get in the oil, not the other way around. The cooling system is under pressure when it gets hot and if the LIM gasket goes bad the coolant will leak out where the cooling passages go from the head to the LIM. It gets into the oil drip channels and into the oil pan from there. There are no oil passages that are under pressure though going between the head and LIM, so oil getting into the coolant there would be very unusual. Typically if any oil leaks it goes down the outside of the block from the center of the valley between the heads, and is usually from not properly applying the RTV sealer.


About the coolant gunking up, are you absolutely SURE that it's oil in the coolant? Some of the long life coolants, and especially the old formula dexcool that originally came in these cars, will get gunky build up in some places if the cooling system isn't bled and filled properly and they are exposed to air when they get hot. They make a pinkish or yellowish sludge where they contact air.

The 1189 code is for the engine oil pressure switch circuit. It really is just a switch and not a sensor, in that it doesn't tell the pcm what the oil pressure is. The pcm supplies 12v power to the switch and it is open when there is oil pressure above 5psi, so the circuit is open and the power goes nowhere. If the pressure drops below 5psi while the engine is running, the low oil pres light will come on. However, if the ignition key is on but the engine has not been cranked yet, and the switch detects pressure for more than 10 seconds, the pcm will set code 1189. It will turn on the MIL lamp only if it fails this test for two consecutive trips, and will turn it off and delete the code and 40 consecutive trips without a malfunction.

Basically what you need to do is inspect the harness plug and sensor plug to make sure they are clean and getting good contact. You might want to take it out of the block too and make sure the end isn't plugged up. Then inspect the wiring harness going to it and make sure there is no damage. Lastly make sure the engine and pcm ground connections are clean and secure. A poor ground can cause a lot of electrical issues. If none of those fixes it, then either the switch is bad, or there actually is a problem causing the code. If the oil system is pressurized while the engine is off, it could be residual pressure in the cooling system doing it. However I'd think a crack in the block big enough to do that would be causing cross contamination both ways.

MikeSilverGT
12-04-2008, 11:48 PM
No worries about driving, it will stay in the shop until this is resolved. I don't run the car hard at all. I idle it when I start until the piston slap goes away and am easy otherwise in my driving. (Not sure what putting it up wet means...)

The car has never overheated, though it was rear ended about a year ago. That wasn't too bad, she sorta went under me and impacted right at the license plate, bent up the borla.

So, you think it's most likely either the head gasket or the LIM gasket? The engine block idea kinda came out of left field. I'll be having a shop do this, should I just tell them to pull the intake manifold and find out? And if they do, they'll be able to see any of the other possible problems?

Aaron, thanks, yeah, I do think it is oil, but not 100% positive. All the coolant in the tank had turned brown this time, but with black streaks and bubbles (sorta like oil in water). I believe the shop thinks it is oil in the coolant as well. That is what is throwing everyone off: the oil is clean, but the coolant isn't. Also, this is very new dexcool, maybe 8 months old.

lone_wolf025
12-05-2008, 12:52 AM
Hope it turns out to be nothing, but I have seen dexcool go gunky especially when mixed with green stuff...I did that once and it looked like oil in the coolant. Keep us posted.

GA2000GTSpeed
12-05-2008, 02:19 AM
honestly i wouldnt put dexcool back in once ur done. ive had nothing but problems with that crap. ive had my car for only 40xxx miles and have had to change the lim twice. and for gm to flush the cloolent cause of the crap they put in. abd ive also been told that dexcooleats through gaskets... idk if thats true but it seems like it.

and when my lim leaked it just leaked coolent out of the engine out onto to ground and it got bad...

Malaclypse
12-05-2008, 10:59 PM
honestly i wouldnt put dexcool back in once ur done. ive had nothing but problems with that crap. ive had my car for only 40xxx miles and have had to change the lim twice. and for gm to flush the cloolent cause of the crap they put in. abd ive also been told that dexcooleats through gaskets... idk if thats true but it seems like it.

and when my lim leaked it just leaked coolent out of the engine out onto to ground and it got bad...

Dexcool isn't the issue at all. A retarded gasket design is, however.

Sounds like all that needs to happen to the OP's car is a LIM gasket change and go from there. Crack in the block? More likely that's what this "tech" is smoking. Noone in the automotive industry worth their weight in grease would suggest a cracked block on a 3400 unless the LIM gaskets have already been replaced with the updated design.

stewartfn18
12-06-2008, 11:02 AM
Dexcool isn't the issue at all. A retarded gasket design is, however.

x2

PhantomLover007
12-06-2008, 11:06 AM
The ONLY way that you could have cracked the block is if you had COMPLETELY ran out of coolant (ie: busted hose, etc) That's the way I had cracked the head on my old LeMans.

MikeSilverGT
12-06-2008, 02:47 PM
Thanks for the advice guys. Well, he called around and got some other people that think it has to be the block as well. Although, I agree it doesn't make much sense that no coolant is getting into the oil. I can't really wrap my head around it either way (The LIM gaskets or a crack) since the oil is always at a lower pressure than the coolant.

I talked to the shop again and they were positive that it's oil in the coolant, so I gave them the okay to pull the intake off. We'll know next week as either they find a crack or it's gaskets.

On the bright side, if it is a crack they seemed confident that it could be welded.

We shall see.

lone_wolf025
12-06-2008, 03:08 PM
Thanks for the advice guys. Well, he called around and got some other people that think it has to be the block as well. Although, I agree it doesn't make much sense that no coolant is getting into the oil. I can't really wrap my head around it either way (The LIM gaskets or a crack) since the oil is always at a lower pressure than the coolant.

I talked to the shop again and they were positive that it's oil in the coolant, so I gave them the okay to pull the intake off. We'll know next week as either they find a crack or it's gaskets.

On the bright side, if it is a crack they seemed confident that it could be welded.

We shall see.

If they say so...if you're not the original owner, its possible someone abused it in the past and the crack is just now starting to become a problem. I suspect once they take apart the intake they'll find the evidence they're looking for, be it a crack or not.

MikeSilverGT
12-06-2008, 03:22 PM
Well, I am the original owner, thanks to 60 months 0.0% APR and their "keep america rolling" campaign... I've pretty much babied it since day 1 and still has a bit of the new car smell.

Also, it's never overheated. I'm pretty suprised about that, especially lately with the coolant gunking up. I've never seen it above 220 and that was with a bad cap. Though I run the heat all the time.

Malaclypse
12-06-2008, 09:00 PM
They'll find that the old-style gaskets have disintigrated as they tend to. Then they'll replace gaskets and send you down the road.

What're they going to see once they get in there anyways? All the coolant jackets that aren't on the head are blocked by the webbing across the valley and the camshaft.

MikeSilverGT
12-08-2008, 06:02 PM
Just an update, but they took off the manifold and the gaskets are (shockingly) good. No cracks were noticed, so they think a cylinder head is cracked. The tech had no idea how that would have happened beyond a manufacturing defect, so I called GM.

Never start a phone call with "Now I know it's no longer under warrenty..." The pontiac help line will hang up on you.

Second call, I got the guy's name first and he set up as if it was part of the dexcool settlement. I don't think it will be resolved that way, but we shall see. Since I'm at 52,800 miles, they may still cover me under the powertrain warrenty, although the car is 6 years old, so they may not.

Anyhow, I'm having it towed to the dealer to be diagnosed. Sort of fitting, that I will be having it towed back to the dealership where I bought it.

lone_wolf025
12-08-2008, 06:17 PM
Hmm interesting. Well keep us posted on any further updates.

PhantomLover007
12-08-2008, 07:05 PM
^^ Ditto

MikeSilverGT
12-12-2008, 07:53 AM
Problem solved. The cylinder head was warped.

I don't get it though, the car has NEVER overheated.

What a nice $2000 Chrsitmas gift for the Grand Am.

350rs
12-12-2008, 01:44 PM
thats part of the downfall with aluminum parts. they are weaker than cast. dosent take much to mess them up. thats the exact reason i wont put aluminum heads on my camaro.

MikeSilverGT
12-12-2008, 05:48 PM
Yeah, sounds like a good plan to stick with cast iron. My next mods are going to be the low temp thermostat and casper's fan switch.

In hindsight though, it explains the misfires. My interceptor gauge was reading a few misfires (2-6 a min at idle, less on highway) but I figured it was normal since it didn't throw a code or an idiot light. But there have been 0 since I got it back (for 30 miles). The power difference is pretty noticable now that I have that compression back too. Go figure.

So to sum it up: Oil in your coolant, clean oil, and a few misfires might mean your cylinder head is warped, but not cracked.

I love the car, but I think I'm done with domestics. No need for crap like this at 52k with the temp gauge never having gotten even to the 3/4 mark.

PhantomLover007
12-12-2008, 05:53 PM
thats part of the downfall with aluminum parts. they are weaker than cast. dosent take much to mess them up. thats the exact reason i wont put aluminum heads on my camaro.

But that's the cost of light go-fast parts in a GA so you can hit 13's... lol

Malaclypse
12-12-2008, 08:42 PM
Yeah, sounds like a good plan to stick with cast iron. My next mods are going to be the low temp thermostat and casper's fan switch.

In hindsight though, it explains the misfires. My interceptor gauge was reading a few misfires (2-6 a min at idle, less on highway) but I figured it was normal since it didn't throw a code or an idiot light. But there have been 0 since I got it back (for 30 miles). The power difference is pretty noticable now that I have that compression back too. Go figure.

So to sum it up: Oil in your coolant, clean oil, and a few misfires might mean your cylinder head is warped, but not cracked.

I love the car, but I think I'm done with domestics. No need for crap like this at 52k with the temp gauge never having gotten even to the 3/4 mark.

A headgasket on these motors isn't exactly a common occourence. So its not exactly fair to condem all domestics because of one faulty gasket. Especially considering that the vast majority of 3400s probably never need head gaskets.

Now if you want to start griping about Northstar headgaskets and lower crankcase leaks? Yeah.... that's a pretty retarded issue.

MikeSilverGT
12-12-2008, 11:42 PM
A headgasket on these motors isn't exactly a common occourence. So its not exactly fair to condem all domestics because of one faulty gasket. Especially considering that the vast majority of 3400s probably never need head gaskets.

Now if you want to start griping about Northstar headgaskets and lower crankcase leaks? Yeah.... that's a pretty retarded issue.

Yeah, I know. I was just pissed off because GM was kinda nasty on the phone telling me it must have been driver habits. Not like I was demanding a freebie, just the mechanic at the first shop felt that on a fairly low milage car a warped cylinder head shouldn't have happened and was telling me to contact them.

Oh well, it runs a ton better now and the piston slap is less noticable! :woot: