New pistons (which rings)?

[theplayer]

I have posted a lot on here in "lifter noise on 02 coupe" about my car. After taking my car into the dealer this time GM told dealer that I needed 8 new pistons to solve my cold start knock problem. So they ordered 8 new pistons. I got the "we'll put the biggest piston in the biggest hole" speech. Here's where I need advice. Dealer said they typically use the old rings on the new pistons when they do this. I asked about new rings but he said that I would probably use oil at first if they put new rings in. My car has 9200 miles on it. So, is it ok for them to use the old rings or do I need to make them give me new rings? How will I know if it will seal properly after they do this?

 

[dmrodco]

WARNING !!! they are trying to cheap you out ! make them fit every piston with the bare minimum clearance and use zero end gap rings . The knock is piston slap caused by too much piston to cylinder wall clearance. they know this they just want to get rid of you long enough to let the warranty run out then your on your own......

 

[theplayer]

Yes I know it's piston slap due to incorrect tolerances. Are you saying make them use new rings and not the old ones? What are zero end gap rings?

 

[dmrodco]

correct do not use the old rings they are just trying to short cut the reassembly . they would have to hone the cylinder walls and fit new rings. IF they wanted to do it right. zero end gap rings give you a better seal since they have no end gap. less chance of any blow by or oil getting around them. Its really a longevity issue. whenever you put new pistons in you should always put new rings. they are cheap insurance. also its too easy for a sloppy mechanic to crack the rings taking them off. you would never know its cracked until its too late then your into a big time rebuild if it doesn't hose up the block too bad.

 

[theplayer]

Sounds like there is too much of a chance for me to be worse off than I was before I let them open the engine. I can request new rings they said. Do they normally come already on the pistons because the dealer wasn't sure. He was going to check. It's suppose to be a good idea to hone the cylinder if you put new rings on and I know they won't do that. I just hope my cylinders are scored are there is some sign of damage so I can just get a new motor.

 

[ron]

The Player, I don't know where you live in AR, but since I live there, too, I have learned that the dealer with a great deal of experience with Vettes and engine problems is located in Fayetville. Members of the Ft. Smith Corvette club have had excellent results at this dealership. Just a thought. I don't know if you have that option, etc. If GM was adamant about not replacing with new rings, I would buy them out of pocket before I would allow the old ones to be reused. Again, my opinion-even though I believe like all postings, that GM should ante up and do the job right. Good luck!

Ron

 

[vettenuts]

I have some noise when my 02 starts, doesn't sound enough for piston slap though. How loud was your car that they are changing the pistons?

 

[theplayer]

Ron: I live in Russellville and am dealing with the dealer here. GM said that the dealer was going out of there way to help me because some dealers just say "it's normall". I don have the right to request new rings and I will if they replace the pistons. I am still hoping that damage is done so I can just get a new motor.
vettenuts: My 02 has 9300 miles on it now. I am the second owner. The first owner took the car in for the knock but was told it was normall. Mine knocks for 4 to 5 minutes when I start it and it is at amibient temperature. It quits knocking when the temp is at abouit 180. At first you can't really here it due to the fast idle. After it leaves the fast idle you can here the knock. It's a sound you have to listen for and is best heard when you stand at the doors of the car. It sounds like it is coming from under the engine or from the bottom. It's not loud but if you know engines you know its knocking. The service manager said that all make noise but mine is louder and lasts longer than it should. If your knocks for longer than a minute after a start and you can hear the knock have it checked to see what they say.