In Denial---No More
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 3,088
Likes: 1
From: NC
In Denial---No More
OK Guys/Girls...My 2001 Coupe A4 has got the dreaded piston slap ...I Think??? I've heard the diesel sound when it's cold since the day I got it. It has 7300 miles now and though it hasn't gotten any worse, I think I've got to bite the bullet and take it up with GM. It is most noticeable at startup and then slowly diminishes but it sounds horrible at about 1500RPM. The car runs strong but I'm afraid to really get on it. Anyway, it's winter and getting cold in NJ so I thought this is a great time to have it worked on if GM agrees. Here's my question(s): Can y'all give me any advice as to how to approach the dealer? I bought the car in AC but would like to have the work done closer to home at Dayton Chevy. Any NJ owners have experience with them? They do sell and service alot of Vettes and their techs seem to be enthusiasts. Are there any things I should look out for? I'm expecting the worst...Ya' know like "They all sound that way" or "That's normal" or worse yet :bs: "I don't hear anything." My only mods so far are the Corsa Indy/X-Pipe and the Donaldson Blackwing. Would you suggest removing the Wing and re-installing the intake before embarking on this journey? Any and all input welcomed...George :confused:
Burning Brakes
Joined: May 2001
Posts: 918
Likes: 1
From: New Orleans, LA
Re: In Denial---No More (georgec114)
I don't know if this will help you, but here is a quote from Hib Halverson's article from the fall 2001 edition of the C5 Registry newsletter:
"This piston knock anomoly that has been occurring in some 97-01 engines after start-ups in cold weather is not a durability concern. It's a pleasibility issue on which there was enough input from customers that GM made a production change. Like the revised rings, there's no performance advantage in switching to tighter clearance and the polymer coated piston. Those hearing a cold piston knock are better off ignoring it until the engine warms a little, rather than subjecting themselves to the stress of a dialog with a GM dealer intended to force repair or replacement of the engine."
Personally, I can put up with a little knock, rather than have a dealership mechanic tearing through my engine.
"This piston knock anomoly that has been occurring in some 97-01 engines after start-ups in cold weather is not a durability concern. It's a pleasibility issue on which there was enough input from customers that GM made a production change. Like the revised rings, there's no performance advantage in switching to tighter clearance and the polymer coated piston. Those hearing a cold piston knock are better off ignoring it until the engine warms a little, rather than subjecting themselves to the stress of a dialog with a GM dealer intended to force repair or replacement of the engine."
Personally, I can put up with a little knock, rather than have a dealership mechanic tearing through my engine.
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 3,088
Likes: 1
From: NC
Re: In Denial---No More (vette2001c5)
Personally, I can put up with a little knock, rather than have a dealership mechanic tearing through my engine.
I understand and agree with the fear...But would it be best to at least have the so called "problem" entered into the system just in case this turns out to be more than just a "pleasibility" issue? I've been reading some threads where the owners have gone through h$ll with dealers ringing and replacing pistons. I'd like to avoid this. Have any owners with this noise actually experienced a failure or catastrophic event in normal driving?
Team Owner
Joined: Dec 2001
Posts: 33,865
Likes: 0
From: Last - We are with you my friend
St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11
Re: In Denial---No More (georgec114)
If it is not too bad, and you can live with it, like you have been doing, wait until the very last moment to take it to the dealer i.e. warranty about to expire :boxing
Racer
Joined: May 2001
Posts: 259
Likes: 0
From: El Paso, TX
Re: In Denial---No More (vette2001c5)
Personally, I can put up with a little knock, rather than have a dealership mechanic tearing through my engine.
Advanced
Joined: Sep 2000
Posts: 93
Likes: 0
From: Stanley NC
Re: In Denial---No More (georgec114)
George,
This is a tough call as others have said. I have the famous whistling manifold on my 2001 and I have scheduled the repair with my dealer. So far I 've had good luck with this particular dealer. I'm just praying they don't mess up my car. This is a fairly simple repair, though. Redoing pistons or rings would give me pause. I would document it under warranty and at least start the process with the dealer you believe is best for the task. You can always say no before proceeding if you see or hear something that makes you nervous about their work. We paid big bucks for these cars, we shouldn't have to live with these annoyances. Start the ball rolling and see where it leads, but as you predicted, be ready for stall tactics, indifference and ignorance. Find a dealer you can trust. This may take some time. Good luck.
This is a tough call as others have said. I have the famous whistling manifold on my 2001 and I have scheduled the repair with my dealer. So far I 've had good luck with this particular dealer. I'm just praying they don't mess up my car. This is a fairly simple repair, though. Redoing pistons or rings would give me pause. I would document it under warranty and at least start the process with the dealer you believe is best for the task. You can always say no before proceeding if you see or hear something that makes you nervous about their work. We paid big bucks for these cars, we shouldn't have to live with these annoyances. Start the ball rolling and see where it leads, but as you predicted, be ready for stall tactics, indifference and ignorance. Find a dealer you can trust. This may take some time. Good luck.
Melting Slicks
Joined: Mar 2001
Posts: 3,259
Likes: 62
From: League City TX
Re: In Denial---No More (Wolfster)
I can agree with you guys to a point.
I.E.: It is an expensive car so...
We must remember that it is an expensive high-performance car. A little piston slap is normal when you are dealing with strong pistons. I personally would'nt want the extra friction associated with a tighter clearance when cold (the clearance gets tighter when it gets hot).
I.E.: It is an expensive car so...
We must remember that it is an expensive high-performance car. A little piston slap is normal when you are dealing with strong pistons. I personally would'nt want the extra friction associated with a tighter clearance when cold (the clearance gets tighter when it gets hot).
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Burning Brakes
Joined: Mar 2001
Posts: 938
Likes: 16
From: North Carolina
Re: In Denial---No More (georgec114)
George - I bought my 99 from AC as well and would take it back there if I needed any service done. I don't live very far from Dayton and have seen some C5s in the show room, but haven't heard much (good or bad) about this dealer.
I know the AC dealer does a large volume and their repair staff would have extensive experience with the C5. It's like choosing a doctor.
I'm one of those folks where the piston slap would bother me. It's not supposed to be there and I'd want it fixed. Hope things work out for you and your car.
[Modified by Sniper168gr, 10:39 PM 1/6/2002]
I know the AC dealer does a large volume and their repair staff would have extensive experience with the C5. It's like choosing a doctor.
I'm one of those folks where the piston slap would bother me. It's not supposed to be there and I'd want it fixed. Hope things work out for you and your car.
[Modified by Sniper168gr, 10:39 PM 1/6/2002]
Le Mans Master
Joined: Aug 1999
Posts: 5,411
Likes: 2
From: N Carolina 08 Z51 Coupe
Re: In Denial---No More (georgec114)
Let it be.... If it works fine when its warmed up, then you don't have a problem, why open up a bag a worms for nothing?
All the Honda cars I have ever owned are loud with knocks and ticks, until it comes up to operating temps. Then it runs and sounds like a swiss watch.
Same with the C5. I get some noise but ignore it until the engine gets up to normal temps... thats when you should start listening...
Mike
All the Honda cars I have ever owned are loud with knocks and ticks, until it comes up to operating temps. Then it runs and sounds like a swiss watch.
Same with the C5. I get some noise but ignore it until the engine gets up to normal temps... thats when you should start listening...
Mike
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 3,088
Likes: 1
From: NC
Re: In Denial---No More (silversport)
It's not so much the noise that bothers me (the Corsa's do enough to drown it out)...It's really the long term effects fo wear and tear...I tend to keep my vehicles a long time with low mileage. My '76 Vette was ten years old with 75K miles on it. I haven't found definitive data to show the piston noise is detrimental to long term use. I'll put it in the system and let y'all know what happens...Thanks to all...GeorgeC
Instructor
Joined: Jul 2001
Posts: 170
Likes: 0
From: Tucker Georgia
Re: In Denial---No More (georgec114)
Now I know what I am hearing, I noticed this "noise" when it got cold here in ATlanta. I only have 2400 miles on my 2001 vert. It seems to quiet down if I let it idle and drive slow for several minutes. What is the repair for this..I don't know what to ask for at the dealer or do I leave it alone if it won't hurt other components....Dogdoc, THANKS GUYS!!! :nonod:
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 3,088
Likes: 1
From: NC
Re: In Denial---No More (Sniper168gr)
Sniper...Thanks for the info...Yeah Kerbeck seems to be the dealer of choice, but it is pretty far from Readington. The info I get about Dayton (other than they just do not haggle on price) is from an owner I met there with a blue Y2K coupe named Mark, who was pretty satisfied with Dayton's handling of issues and from my boss who had a Ford Contours SVO and they did a transmission replace beautifully...Now that's a far cry from a C5 engine build, but he said they hire experienced techs who have their own Vettes. I think I'll at least pay them a visit and Kerbeck as well...GeorgeC :flag
Le Mans Master
Joined: Sep 2000
Posts: 5,027
Likes: 320
From: N. CA
Piston Knock
I also had the cold engine knock in my Z06. But after hitting the rev limiter more times than I have fingers to count, the knock is GONE! :D
Yeah, give it some good `ol blasts and see if that don't take care of the carbon that has built up in the chamber. Sure worked for me.
Sounded like a diesel engine in the cold taking off :U
but no more!
Maybe a decarbonization would take care of it in your case.
Yeah, give it some good `ol blasts and see if that don't take care of the carbon that has built up in the chamber. Sure worked for me.
Sounded like a diesel engine in the cold taking off :U
but no more!
Maybe a decarbonization would take care of it in your case.
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 3,088
Likes: 1
From: NC
Re: Piston Knock (BOBSZ06)
Bob, Not sure if that's the official GM fix?!?!? ;)
I do admit to babying it a little too much though. Actually, it is amazing how few opportunities I get to really get on it. You can't go two blocks in NJ without running into some sort of law enforcement. Matter of fact, a few weeks ago I got behind this caravan of all black SUV's...They were holding me up so I blew by them. I realized this caravan all had US Gov. plates heading into NYC and were probably filled with secret service or FBI types. No fingers were displayed. But I'm sure I got their attention.
I think this weekend the weather will be nicer and the roads will be cleared off, I'll "wind 'er up a bit."...GeorgeC :)
I do admit to babying it a little too much though. Actually, it is amazing how few opportunities I get to really get on it. You can't go two blocks in NJ without running into some sort of law enforcement. Matter of fact, a few weeks ago I got behind this caravan of all black SUV's...They were holding me up so I blew by them. I realized this caravan all had US Gov. plates heading into NYC and were probably filled with secret service or FBI types. No fingers were displayed. But I'm sure I got their attention.
I think this weekend the weather will be nicer and the roads will be cleared off, I'll "wind 'er up a bit."...GeorgeC :)
Team Owner
Joined: Sep 2000
Posts: 25,019
Likes: 2,712
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Re: Piston Knock (georgec114)
My car has a noise that might be piston slap- it goes away when the engine warms up a little. But the noise doesn't start until a minute or two after engine start, and I thought that piston slap would begin immediately. Any advice?
Instructor
Joined: Jun 2000
Posts: 190
Likes: 0
From: Ozark Mountains
Re: Piston Knock (georgec114)
Hib speaks the truth.
I had a '76 Corvette with an L-82 engine (detuned LT1) that had forged pistons which knocked when cold. The alloy they were made of expanded a lot when they warmed up requiring cold clearance to be such that they knocked when cold. It had 50,000 miles on it when I tore it down to fix "the problem". I wasted my time and money! Everything was still perfect, no damage what-so-ever.
Just turn up the radio for a minute or two until the engine warms up a bit.
I had a '76 Corvette with an L-82 engine (detuned LT1) that had forged pistons which knocked when cold. The alloy they were made of expanded a lot when they warmed up requiring cold clearance to be such that they knocked when cold. It had 50,000 miles on it when I tore it down to fix "the problem". I wasted my time and money! Everything was still perfect, no damage what-so-ever.
Just turn up the radio for a minute or two until the engine warms up a bit.