3.4 head gaskets, exhaust, timing problems

[rossgt]

Hello,

I'm not a regular here... and for those who have replied to me in the past you know I have one messed up 3.4 that I havent been able to fix...

I was talking to some people from w-body and they suggested i describe what my car does and maybe you guys can help better.

This is a 1992 3.4... auto... in a GP.

When I start the car cold, it will start up alright, idles at about 1000. However, the exhuast chugs and spits out whitish gray smoke for about 10 or 15 seconds and stops, but continues to chug. The engine also shakes. it idles and runs rough... but still runs.
If I were to shut the car off and start it again, the only way i can get the ignition to catch is by reving the car, and eventually it will start, and shoot out the same white smoke. If i dont give it a little gas it will stall.
The oil is like an amber/honey/caramel color...
This all happened after the pulley on the timing belts went at 100k... and after the mechanic "fixed" the car it was acting this way. Ive been told it is the head gaskets, but i dont see how they would be shot from a timing belt failure.
Im at school right now and dont see the car for weeks, which is why i havent fixed it yet. However, I would appreciate it alot if someone with good 3.4 knowledge would enlighten me on what could be wrong, if its the HG or something else.

Thank You.

[pbui3057]

I would do the simple things first. Check wires, plugs, filters, etc. You never know you might get lucky. Also check compression and the things that are easy to get to without much wrenching. No use in tearing it all apart if you can check the easier things first.

The next thing I would do is to have your timing checked again. You put fixed in quotation marks which to me means that it isn't quite right from the beginning. Maybe take it to a different mechanic or retime it yourself. There are a couple of good guides on this site that shows you how to check the timing.

I always thought that white smoke meant burning water or coolant so it is a possibility to have the head gaskets leaky. Has your car ever overheated or anything like that?

After you have the timing rechecked, check the upper and lower intake manifolds. Those seem to be the easiest gaskets to check as far as gaskets go. Or so everyone here says.

After that, take it to the GM dealership and for $90 have them do a diagnostic on it. They can usually pinpoint a problem and tell you what the problem is without actually doing the repair work. Then you can either do it yourself or have them do it. Whatever you decide to do, try the easy small stuff first.

[873.1]

exact symptoms of a blown head gasket.

[rossgt]

Thanks guys...

I just dont see why the HG's would go when the timing belt went, but who knows... I'm trying to avoid replacing the engine and doing a rebuild, but to figure out what is going on would be a big help.

The mechanic, who is a fly by night type of guy, said that it was the HG. It does show the signs, but I had heard that it could be something else.

Any, thanks for your help... I appreciate it!

[PlatinumZ34]

the white puffs could be caused by timing, if the puffs smell like gas.

When my car is started in command start and in "Command Start Idle" as i call it, it will chug a little bit here and there letting out some gas (white puffs of smoke, it does it when it floods in one or two cylinders). The command start messes with my ECU, it doesn't deliver spark at the right time and i think it completely misses the 5th cylinder to be honest, but anyways. As soon as its out of CSI (command start idle) it runs fine with no chugging or white smoke, so its definately not a HG for me, since obviously it stops, and i can smell the gas as it puffs. And its not the ECU everythings fine without the command start, the intelligent man who wired it and knocked off 800 vaccum lines can answer your questions as to why the command start would do that.

My bet is plugs, wires, coils, timing. Check those. Trust me, you'd know if it was a HG, people behind you wouldn't be able to see through your smoke.

since its whitish gray as you said, i'd say its flooding but whatever, if he says headgasket then go for it, he's the mechanic.... looking for money :P

[rossgt]

after the startup, it only smokes when i step on the gas an excellarate. Its not like a giant cloud of smoke, but defiently noticeable.

The mechanic who worked on it before I owned i t when this happened was trying to get the lady to sell it to him, so who knows what he did in there. He kicked me out of his shop when i went to ask about it, becuase I owned the car.

I wanted to figure out what is really wrong in there, so i didnt tear everything up for nothing. Again, thanks for your time and help.

[bud36light]

try a plug check first. You can usually find a blown head gasket by the color. If there is no dif then at least check the timing. Ive never tried this but somebody here said if you time both banks of cam flats up it will start and run but sound and run like shit.

[rossgt]

Well someone told me that if the timing chain or timing is off it could be causing this problem. It only did this after the timing belts were changed... so maybe the mechanic didnt kknow what he was doing and the timing is off?

[Juglenaut]

The engine may also be burning lean in a few cylinders over the other ones, going on from what was said earlier. In proportion, flooding is a over rich state compared to adjacent cylinders, same as when a lean condition exsist compared to the adjacent cylinders the outcome would be about the same.

I would check timing then check fuel delivery, or check fuel delivery first.

I got White smoke puffs on Accel from losing fire in 2 cylinders, 2 bearly working injectors causing a lean practically dead fire, and two worn out plugs coupled with a stiff fuel filter that was about to sieze. My engine gluged like a crazy and was twice as loud as it were if it was running on all 6, sounded like a Ricer wind up fart toy lol. Of course I had flow thru muffs.

[rossgt]

jeglenaut, did this occur to your car after a specific event?

[RednBlack]

Thanks guys...

I just dont see why the HG's would go when the timing belt went, but who knows... I'm trying to avoid replacing the engine and doing a rebuild, but to figure out what is going on would be a big help.

The mechanic, who is a fly by night type of guy, said that it was the HG. It does show the signs, but I had heard that it could be something else.

Any, thanks for your help... I appreciate it!

Could be the other way around. Old timing belt gave way when the head gasket blew..

[rossgt]

It was a new-er belt, the pulleys went... so who knows what went on in there.

[PlatinumZ34]

it's starting to sound more and more like a headgasket as you go on.
If its white when you accelerate and its enough to notice then its probably a headgasket.

o and as a side note, i just purged my injectors... wow... i didn't think it would make a difference but it pulls a hell of alot harder/more consistently then it did before in second gear... i didn't really get to test anything else yet, it also stopped chugging in CSI . So looks like my next purchase is some new injectors.

[bud36light]

My #4 head gasket blew. I got a barely visible puff of white smoke at start up only. This fouled the #4 plug a couple of times b4 I figured out it was blown.

[rossgt]

Hmmm...

I really hope its not the HG. The cam timing would be easier to get fixed. Would it be possible for the HG to go when the timing belt slips off? I dont know, it just seems to me that it would be more likely that this hillbilly mechanic didnt do the cam timing right when he "fixed" it... and just told the owner that it was the HG becuase it has similar symptoms.