Need Help

[GPLady]

Can someone help me. I need to know which gaskets I need to purchase when replacing valve lifters in an 02 Grand Prix GTP V6 3.8L Supercharged. Any advice would be welcomed.

[GTP Dad]

Welcome to AF!!

You will need the upper and lower intake manifold gasket set. Along with a set of valve cover gaskets. Check with the store when you go to purchase the gasket set. If you tell them what you are doing they should be able to help you out with everything you need. Also, don't forget fresh oil and coolant as you will need both if you pull the upper and lower intake manifolds also this would be a good time to change the thermostat.

[GPLady]

Thanks GTP dad. I have one concern on the replacement of the lifters. I am not a mechanic, but know a little about cars. How can I be sure it is the lifters that are bad. When I start the car it has a very loud tapping noise and has gotten worse over the months. It started the end of last year, but only did it for about 3 weeks then quit. It just started making this noise again about a month ago. My neighbor, who has his own shop, heard the noise and wanted to be there when I cold started the car the next morning. He was there the next morning and listened when I started the car. He told me I had several lifters that were bad and that I may as well replace all of them while they had the engine apart. My concern is, how can I be sure it is the lifters. I would hate to spend all this money on parts and labor only to find out it is not the lifters. Is there a possibility it could be something else? The only reason I ask is that I have been ripped off by other mechanics and do not have a lot of trust in them. Once again any advice will be greatly appreciated.

[doctorhrdware]

If you can record the noise and post it here for the people here to listen to the noise.

[GPLady]

Sorry doctorhrdware but have nothing to record the noise. Also, this may sound silly, buy how would you "listen" to it online, LOL. Not making fun, just curious.

[doctorhrdware]

Well it is not a silly or dumb question since you do not know. The only dumb or silly question is one that is never asked. I have a cell phone that I can record audio and video and you then post it on utube and post the link to the utube recording.

[GPLady]

Morning doctorhrdware, I will see what I can do to record the noise. Might not have any luck but will try. If I cannot record the noise, is there another way to determine if it is the lifters? I just want to be sure the right thing gets fixed and not get the lifters fixed only to find out its something else. Trying to be sure and cost effective.

[richtazz]

Keeping it simple (since you admitted not knowing a lot about cars), the lifters in your engine have hydraulic adjusters in them. When they go bad, the hydraulics get weak, causing the valve train to make noise due to being out of adjustment. When the mechanic gets the valve covers off, if any of the pushrods (it's a hollow tube that sits in the top of the lifter and connects it to the rocker arm) are loose, then the lifters are collapsed and the cause of your noise.

[GPLady]

Thanks Rich, I kind of know what you are talking about concerning the lifters as I have a diagram of the internal engine components. It helps me understand things a little easier. My mechanic told me to put in a pint of Marvel Mystery Oil to see if that would quiet the lifters. It did not. He told me to leave it in for a week then have an oil change. I plan on getting the lifters replaced in about two weeks so will it hurt to not to do the oil change until he replaces the lifters? The reason I am asking is that when they do the lifters I know they will have to do an oil change. I am also having him install new spark plugs as the car is missing really bad. Also will it further damage the engine by driving it for the next couple of weeks until I have the work done? I do not drive it unless absolutely necessary. When I start the car, I wait until the tapping noise has completely stopped before I move the car. This I know allows time for the oil to get to the lifters.

[richtazz]

Hmm...being an 02 model and since it's missing, you may want to have the catalytic converter checked. The resultant back-pressure build-up can cause noises similar to lifters ticking due to knock/ping. There is a GM TSB regarding known issues with the converters in 01-02 Grand Prix's clogging up. If your car has less than 120k miles on it, it may be covered under an extended warranty for free (if the converter is bad).

[GPLady]

Rich, what is a GM TSB. My GTP has only 58,000 miles on it. I do not have any warranties on the car. If it is the catalytic converter being clogged, would this cause the car to seem like it doesn't have enough power to start the car(the only thing I can say to describe what happens). I have noticed several times that when I first start the car, its like there isn't enough power to make it run right. Does that make sense? It really runs rough, like it isn't firing on all the cylinders. It really scares me every time I start it. That is why I am wondering if it is the lifters and not something else. Just trying to pinpoint the problem. Even my mechanic told me it is so odd for a car with so few miles on it to be having several lifters go bad. God this car is driving me crazy. One time when I started the car and it was doing this with the not running right, my check engine light came on. I took it and had the code read and was told it was misfiring on cylinder 4. That is why I bought new spark plugs. The man told me to start there on the missing. Then proceeded to list a million other things I could do. Yeah right, like I have thousands of dollars to throw away. NOT.

[richtazz]

A GM TSB is a Technical Service Bulletin that they issue to dealers service depts when there is a known issue. This covers the known bad catalytic converters for 7 years/120k miles and is valid even if you're not the original owner beyond any new car warranties that have long since expired. Call your local GM dealer and see if your car may still be covered. If the converter is indeed bad, it may be a free fix.

Also, since the misfire is in cylinder 4, do you use 87 octane gas on a regular basis, or do you put in premium as required according to your owners manual? 87 octane causes preignition and knock (especially at higher RPM when the supercharger is making boost) which can destroy your engine, and cylinder 4 seems to be the one to fail first due to this issue.