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-   -   Cylinder misfire again. LIM or Head gasket? (http://www.grandamgt.com/forum/showthread.php?t=90576)

mach158 07-16-2014 01:06 PM

Cylinder misfire again. LIM or Head gasket?
 
I have a 2004 grand am with the 3.4. I am having problems again with a misfire in cylinder 1 (code 301) When engine is cold I can start it and it will idle rough and can smell unburned gas and after 15-20 seconds it smooths out and runs fine. If i try to drive in that 20 seconds it will bog down and have no power.

I have replaced the spark plug in this cylinder twice due to cracking of the plug. It has new wires as well.

My main concern is this may be a LIM issue or headgasket putting coolant onto that plug and causing the plug to go bad. I have no had a chance to dive in to look at it yet but last time I replaced the plug it showed no signs of being a LIM issue. Found no coolant in the oil or external signs. The only other thing I notice is i will gradually loose coolant over a long period of time. Like after 2 months my low coolant light will come on and only for a short period of time.

I am fine with doing a headgasket or LIM repair I would just hate to go through all that work for something I may be over looking so thoughts on this matter would be great.

Dave Carney 07-25-2014 06:32 PM

1 Attachment(s)
I think it's your head gasket. Cylinder #1 is generally where they blow. Here is a pic of my wife's engine (2002 Grand Am) that I took during my teardown. Note how nice and clean the #1 piston is from the steam cleaning action of the leaking coolant.

Go ahead and tear it down, use a good felpro headgasket and the problem solver LIM gasket while you are at it. They are worth fixing.

plastic_indian 07-25-2014 09:43 PM

"cracking of the plug"? The old sparker shows an actual fracture in the porcelain insulator around the electrode? Fracturing a tip is typically caused only by a foreign body in the chamber or gross detonation in the affected cylinder. What flavor coolant is this power plant running? Green coolant leaves a telltale signature in a wet hole, but Dex often is misread. Post a pic of the offending plug. Contrary to popular belief, 3400s don't pop head gaskets with much frequency absent a legitimate overheat condition. If the plug tip is truly cracked, the head should come off for the purpose of inspecting the chamber for debris, if nothing else. If "cracked" is actually carbon tracking, a HG problem is not ruled out, but other problems can be ruled out before going to the bother of yanking the head; any liquid (coolant, wet fuel) can induce the spark to track down the tip to ground and leave a tracer. Does this cylinder post comparable compression/leakdown numbers to other cylinders, hot and cold?

Dave Carney 07-26-2014 06:18 AM

Quote:

Originally Posted by plastic_indian (Post 1252701)
Contrary to popular belief, 3400s don't pop head gaskets with much frequency absent a legitimate overheat condition.

I don't think that's true particularly if you read all the posts here, but I will just go on record as saying my wife's car had only 51k miles (easy miles) on it and had never overheated in the slightest. We also did a LIM at 22k. We had missing coolant and eventually tell tale white exhaust smoke.

plastic_indian 07-28-2014 08:39 PM

Quote:

Originally Posted by Dave Carney (Post 1252710)
I don't think that's true particularly if you read all the posts here, but I will just go on record as saying my wife's car had only 51k miles (easy miles) on it and had never overheated in the slightest. We also did a LIM at 22k. We had missing coolant and eventually tell tale white exhaust smoke.

As always, Your Mileage May Vary, but from the perspective of an automotive professional, the percentage of 60 degree head failures occurring in concert with an overheat is very near 100% in personal experience. Phrased another way, those 3x00 head failures accompanied with "it never overheated!" stories, in my own experience, typically presented low on coolant with evidence of long standing coolant leak problems.

AaronGTR 07-29-2014 05:06 AM

I'm with Mark on this one. Head gasket failures are actually not that common on these engines unless they overheat. That's not to say it can't happen, but it would be in the minority of cases.

mach158 08-10-2014 07:07 PM

Sorry for the delayed response, I thought I subscribed to this thread and never got an e-mail so I forgot all about it.

The car has about 90k miles on it and I have been putting the universal (or so it says its good with all coolants) coolant which is green in the car. I haven't had to add any for awhile and have not had a problem for the past couple weeks.

When I say the plug cracked I am referring to the porcelain outside of the cylinder. I have not noted any issues inside the cylinder with the spark plug. It could possibly be installer error I guess but I find it hard to believe the time frame is so far apart from install to issues if I cracked it during install.


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