2002 g/a bought used. About 2 years ago (about 50K miles) started surging hesitating. Mechanic replaced intake manifold gasket...a few months later started doing same thing again. Diagnostic machine said O2 sensor bad: replaced. Car ran fine again until a month or so ago...service engine soon light came on again and diagnostic again said O2 sensor which we replaced again about a month ago...but now has started doing it again (very badly this time...almost didn't get home tonight). Worse when enging hot or ac is on. Tired of no one being able to diagnoseepair. Reply to ncroadkingdoc@ aol.com
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Driving the car would cause even more damage. I believe that the engine was being overheated , probably due to a faulty thermostat which is an inexpensive part. Now , coolant is getting into one of your cylinders , the chev dealer says the intake manifole , my guess would be the head gasket.
Either way , avoid dealerships and find a reputable small mechanics garage. If it is the intake manifold gasket , the job might not be too expensive. If it is the head gasket it could be somewhat more $$. At 80,000 miles , your car was due , or overdue for a new timing belt. The timing belt job and a head gasket repair could be done together to save some $$. Kinda hard to explain , but a mechanic could explain my logic..
Either way , the most important thing is to find someone who can properly diagnose the problem , AND THE CAUSE , and fix the right thing. No use doing a manifold gasket only to find out later that it is the head gasket.
AGAIN......... The dealership will be the most expensive place to have work done on your car , unless it is under warantee
Look at the intake manifold gasket. This problem appears to be common on 1990s series Chevrolet small truck engines. It is a time consuming job to replace the intake manifold gasket.
You can purchase an intake manifold gasket set from a local parts store. It should have the upper and lower intake gaskets contained in it. I see you plan on doing the valve cover gaskets as well. It might be a good idea to replace the plugs and wires at the same time to save some trouble down the road. I would recommend doing the oil change and change the thermostat at the same time as well.
If the top hose is hot and the bottom is cold, your definitely not getting circulation. You,ve already done alot of work to this vehicle so you have pretty much answered your own question. About the only thing left is the heater core. Of course, I dont want to be the one to tell you it is definitely the heater core because obviously I am not looking at the vehicle. But If i was a betting man, thats where my money would be.
take plug,wire,coil and swap with another cylinder if still #5 missing could be head gasket or intake gasket leaking could also be fuel delivery problem
completely agree with emissionwiz. intake manifold gasket needs replaced. it took me 12 hours to do mine 2 months ago (a known pontiac defect). buy the top of the line replacement metal gasket. pontiac used a plastic gasket when they produced this engine, 3.1, 3.6 and 3.8 engines all have the same problem. i took my time and also replaced the hoses, thermostat, etc. and lastly....after you finish adding coolant dont forget to bleed air out of the the system. the screw should be painted blue....nice weekend job...take your time.
×