If lets say GM was to cover the replacement of my Rings and Pistons because of the oil consumption problem would it be possible to swap out the GM pistons for something better?

Of course I would pay the difference for the better set, but would GM go for that and if so then what would be a good replacement?

Has anyone tried going down this road?


thanks

 

You might be able to get them to install the pistons, but I bet you'd have a very difficult time getting them to provide any type of warranty for the work! Good luck!!!

 

Yep, I’ve been there. I went all the way to arbitration with the piston slap problem on my '02. The Better Business Bureau's arbitrator was selected at random from a list of licensed local arbitrators. The arbitrator and I were in his office in San Diego, and the GM representative from Bowling Green was on the speakerphone. I pled my case and introduced all my GM documents, and consumer letters, that I had downloaded from the Internet identifing the problem. I also introduced all my dealer’s work orders. I even had one of the dealer's work orders where the GM tech had written that the problem was cause by excessive tolerances between the piston and the cylinder wall. The proceedings were tape-recorded and the GM representative read a prewritten canned speech for the record. His speech lasted about 6 or 7 minutes, and basically all he said was that GM is aware of the piston slap problem and that the problem it is well documented. He read on that GM feels that the problem is well within acceptable tolerances and the piston slap problem, in GM’s opinion, does not negatively affect performance or safety, so it will not be corrected. Both myself and the GM rep on the phone had an opportunity for a summation at the end. I stated that I had purchased my vehicle new, off of the showroom floor, and I as a consumer should have the reasonable expectations that the product I’m buying if free from defects. I also mentioned that I had purchased GM’s 7-year extended warranty to avoid these types of problems. The GM rep's summation was basically that in GM’s opinion, if the C5 motor is driven too much, it can cause problems with carbon build up result in piston problems. he then said if it’s not driven enough, it can cause a problem with seals drying out and leaks. It sounded like a “no win” situation. At the end of the hearing, the arbitrator (who was a retired nuclear power plant supervisor) inspected my vehicle and listened to the tapping sound. Ten days later I received a letter from the Better Business Bureau stating the based on their arbitrator's recommendation, they were denying my claim. The arbitrator based his decision on the fact that GM claims that the problem is an “acceptable” problem. Go figure?

 

The fix for the excessive oil consumption problem (which is separate and unrelated to the piston slap problem) is limited to certain MY cars and also only involves the replacement of the #2 ring with a more aggressive Napier scraper ring. The problem was identified by GM engineers as being a function of high-rpm/low-load driving conditions which causes ring flutter which allows oil to migrate into the cc. When the re-ring is performed, the tech only replaces the #2 ring and must return the original pistons to their respective positions. Otherwise, the cylinders must be re-honed. The re-ring alone requires no machine work as such and so the shortblock can even remain in the car. Any additional work involved in replacing your pistons would most certainly have to be negotiated with the dealer.

FYI, below is the TSB outlining the fix for excessive oil consumption.

Best of luck in your repair.

Subject: Higher Than Expected Oil Consumption (Replace Rings and Engine Valley Cover)
Source: Chevrolet Dealer Technical Service Bulletin
Number: 01-06-01-023A

Models: 1999-2001 Chevrolet Camaro, 1999-2002 Chevrolet Corvette, 1999-2001 Pontiac Firebird, with 5.7L Engine (VINs G, S -- RPOs LS1, LS6)

This bulletin is being revised to add model years for the Corvette, information on the LS6 engine and parts information. Please discard Corporate Bulletin Number 01-06-01-023 (Section 6 - Engine).

Condition
Some owners may comment on higher than expected oil consumption. When checked, the oil consumption could be in the range of 400-600 miles per quart (700-1000 km/L).

On the LS6 engine only, the technician may find oil behind the engine throttle plate and in the intake manifold.

Cause
The cause for this condition may be an interaction between the piston rings and the cylinder bore in vehicles that are operated at higher RPMs -- typically manual transmission vehicles driven in a manner where the engine is frequently or consistently operating at greater than 3200 RPM.

On the LS6 engine only, the engine has a unique aluminum valley cover that has composite oil separating baffles and PCV plumbing incorporated. In some cases, the PCV baffle may not be properly sealed to the valley cover, causing oil to enter the PCV system.

Correction
On the LS6 engine only, replace the engine valley cover if oil is found behind the throttle body or in the intake manifold before replacing the piston ring. Refer to Engine Valley Cover Replacement in the Engine Mechanical - 5.7L subsection of the Corvette Service Manual.

A new set of piston rings is currently available through GMSPO. The new rings are part of a complete piston ring kit. Install only the number 2 compression ring and the oil expander ring from the piston ring kit. All other rings in the piston ring kit should be discarded. The original number 1 compression ring and the oil ring rails should be re-used in their original positions on the piston. All pistons should be used in the same cylinder bore.

Important
Do not dress or hone the cylinder bore. Nothing should be done to change the bore finish for this condition. Changing the bore finish may aggravate the condition.

Refer to the Unit Repair Manual for appropriate ring removal and replacement procedure.

The number 1 compression ring and the upper and lower oil expander rails are re-used because they are already broken in for the bore that they are in. The new number 2 compression ring is made with a very sharp edge that will break in quickly.

Changing only the piston rings noted, with no change in driving style, should change oil consumption to an acceptable level. Changes in driving style that reduce the amount of time spent at higher RPMs will also positively affect oil consumption.

In addition to the standard size piston ring kit listed below, a 0.25 mm oversized piston ring kit is available. The oversized piston ring kit should only be used in those rare instances where the cylinder bore size has been machined larger to accommodate the 0.25 mm oversized piston rings.

Parts Information

Part Number
Description
Qty

12568002
Valley Cover
1

88984247
Ring Kit, Piston
8

 

I had the rings replaced on mine for the oil consumption problem, but never thought about replacing the pistons. I doubt my dealer would have wanted to do that since it could affect the warranty and their liability. Don't know if they would have allowed me to sign a waiver, but I didn't want to anyway since I wanted the warranty to be in effect.

 

Thanks Guys.

I am burning through 1+ quarts of oil around every 800 miles which even GM thinks is too much.

Thanks Patches for the detail listing of what is done. I was under the impression that something more had to be done that is why I was considering new Pistons. If this is all that needs to be done (well I know it is no small job) then I will travel down the piston road another day with someone besides GM.

 

The GM replacement pistons are manufactured by Mahle and are very good pieces. Same manufacturer who makes C5R pistons for the factory ALMS racing team.

Unless you're going to supercharge or use nitrous oxide, I'd say stick w/ the new design GM/Mahle cast pistons and you'll be happy.

 

Good to know.... Thanks

 

I wish you good luck on even getting GM to replace your rings. My claim at my Arbitration Hearing with GM, was that my engine had piston slap (confirmed by the GM Technician) and that the engine was burning an excessive amount of oil. Part of the canned speech that the GM representative read into the record at the Arbitration Hearing was that burning a quart of oil every 1000 miles is not considered by GM to be excessive oil consumption. My only demand of GM was that they authorize the dealership to examine the pistons and rings for any excessive wear or possible defects. The GM representative wouldn’t even agree to that. My claim and request was completely denied. GM would authorize absolute nothing.

 

Merlin - I hear of weird stories where sometimes they don't cover it. My arguement would only be that if I am burning through 1+ quarts in 800 miles in the standard oil change life of 5K miles I would have used over 6 quarts of oil which is not acceptable even by GM.

Sorry to hear that you got the shaft without any lubrication....