'92 DOHC ruined?

[rossgt]

HI,

I just came here from w-body...
I may be getting a 92 Petty Edition grand prix with the 3.4L DOHC but its got some problems.
Three years ago the timing belt went and supposedly it suffered valve damage. Since then it has been burning oil alot upon startup. Last week, the car stalled, the owner said that the engine was out of water (?) and after getting that fixed she has decided to retire the car.
Does anyone know what might really be wrong with it? she was kinda vague about the problems, but whatever it is it must be a result of this valve probelm...

Thanks guys,
-Ross

[Lyle's GTP]

Sounds like rediculously poor maintenance. Be prepared to rebuild the engine. Plus if it ran with no coolant, there is a good chance the head(s) could be cracked. (not conventionaly repairable) Also if the engine was treated like that, be sure the tranny needs work as well.

Lyle

[Lowerd1]

That owner will be the first to start bad mouthing the 3.4DOHC now. People like that are the ones that give this engine such a bad name. Well and the other owners working on them and smashing a finger. Shoot the words just fly out my mouth about it, GM, and anything else I can think of.

Its a non interferring motor so the valves may not be damaged. You are going to have to pull the heads to change most likely. Pull them and check the valves, and also check to see if maybe the head is warped or cracked. While you have the heads off might be a good times for MODS!

[rossgt]

Thanks guys,

Im hoping that there is some hope to at least keep the car running. Its pretty rare and I'd hate to see it go. The owner did take good care of the car, suprisingly enough. She had the timing belt changed at 60,000 miles, but its supposedly 'slipped off the pulley" one day around 120,00... resulting in the engine damage. She said she always had the oil changed, fluids full, stuff like that. I would suppose the coolant was leaking or something- whatever the problem with that was it was resolved and i just have the valve damage/oil burning to worry out

thanks for your help!

[Lowerd1]

Is it burning oil or just losing oil? If its losing oil, it may be a Leak like the pesky oring leak!

[rossgt]

its burning oil.... smokes alot out of the exhaust when you first start it up. My 95 GT leaks alot of oil tho

[pocket-rocket]

If it is on startup, and the engine has alot of miles on it, I wouldn't doubt it if the valve seals are going bad. You could just replace them with leaving the heads on, but if it already has that kind of mileage, why not just get a FelPro head gasket set (about $118 at Advance), have the head pressure checked and decked (most places clean them with this service), change the dist. O-ring, and change the timing belt if it has about 30k miles or more on it. This engine is not a pushrod, and does need some keeping on top of it to keep it in good conditionl

[rossgt]

Thanks,

I would like to try to do as much work on the engine myself to keep repairs down. She said it had vavle damage from when the timing belt fell off the pulley, how serious is that and can it be fixed?

[Lyle's GTP]

If the engine was running it couldn't be that bad. So it's definatily repairable.

Lyle

[pocket-rocket]

Like Lyle said, it is repairable. The engine is designed as an non interferance engine (the valves do not say hello to Mr. Piston when the belt breaks, or shreds in my one cars case). They did have the tolerances so close for the valves and pistons that if the belt let go at high rpm's, some cars do suffer valve damamge. We don't have any special valves in our engines (like sodium filled) so I don't thing valves are very expensive. If it really does have valve damage, when you get the new valves, be sure to lap them to get a good seal. I would even take out the old ones and do them to, to make sure they don't leak. And change that dist. o-ring while you have the heads off for sure, to save yourself a huge headache later.

[rossgt]

sounds like alot of fun...
just as long as i can keep it running i should be alright for the time being

thanks again!

[pocket-rocket]

Try to track down a Helms manual on ebay. It is the factory shop manual, and will make life easier.