2002 c5 Knock in motor
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
2002 c5 Knock in motor
I just took delivery of my 02 convertable on 10/3, when I started it up the next day it had a knock in the motor. I took it back to the dealer and they replaced all of the lifters (i asked them to replace the car but they refused) when I got the car back, the next day it made the same noise. I returned it to the dealer, they said it was a new noise and they would more than likly replace the motor (I didnt like that, I wanted a new car) The dealer kept it for two weeks and then told me that they have "some problems with pistons" and the noise was inherant of the new ls1. So they refuse to any thing about it, they did offer my a free extended warranty. I have started the lemon law program. Has anyone heard of this problem,and what has happened? This is my 3rd c5 and I never heard this noise before. Thanks for any info. vakavette
Le Mans Master
Joined: Sep 2001
Posts: 5,022
Likes: 1
From: TEXAS
Re: 2002 c5 Knock in motor (vaka)
Just some thoughts: Typically, normal sounds you will here are the fuel injectors and piston slap when cold. Not normal sounds are bent push rods, which has been a problem with the LS1. Note that all of the noises listed above sound very similar, so it's hard to tell which it is. Bent push rods occur when down shifting, causing the RPM's to rise too high. The rev limiter does not function when down shifting. Of course, your problem may not be any of these. If you pursue the Lemon Law, be sure to follow the instructions very closely and do everything you are supposed to do. There is a specific program to follow in order to be successful. Good Luck.
Safety Car
Joined: Mar 1999
Posts: 3,630
Likes: 8
From: Virginia Beach Virginia
Re: 2002 c5 Knock in motor (vaka)
Simple solution, go back to the dealer and let them allow you to start another brand new '02 on the lot. Listen to that one and see if there is a difference.
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
Re: 2002 c5 Knock in motor (Mark S.)
Thanks Mark, I did that with the three other vettes they had there plus I have done it with 5 others..NO NOISE!!.. Vakavette
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
Re: 2002 c5 Knock in motor (Buckmaster)
No mods, it has an auto, 93 octane. The car only had 15 miles on when the noise started. Also I didnt do any downshifting so bent pushrods are doutful, but possable. Thanks for the lemon law tip, the BBB has been very helpful. My hearing is going to be sometime within the next 30 days,will post results.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Re: 2002 c5 Knock in motor (vaka)
The first two weeks of 02 production used the left over pistons from 01. In 02, the pistons used were coated to prevent piston slap when cold. Check the production date of your car, this may be the problem. I have an 02 and the motor is quiet as a mouse, both cold and hot. I agree with you, with the crap the dealer has put you through, make them buy it back. Good luck, hope it comes out OK. From you description, the dealer is either an idiot or a liar.
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
Re: 2002 c5 Knock in motor (vettenuts)
The general service manager did mention a problem with "the wrong pistons" and said it had something to do with "plastics"??? I dont know about he dealer ether, anymore, over the last 12 months I have spent over $135,000 on cars with him. Iguess its time to look for a new dealer.
Pro
Joined: Jul 2001
Posts: 615
Likes: 2
From: Brea, California, USA
Re: 2002 c5 Knock in motor (vaka)
Have the same knocking noise that I was also told was "normal" While it doesnt seem to effect the performance it certainly doesnt sound like a very refined motor.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
Re: 2002 c5 Knock in motor (Chifo Jr)
It is hard to belive that ANY knock in a motor is normal. One of the problems I have with it is I dont keep my cars longer than 18 months to 2 yrs, and when I go to sell it what is a buyer going to say?? I feel it will devalue the car, I wouldent buy a used car with a knock in the motor.
Le Mans Master
Joined: Feb 1999
Posts: 6,269
Likes: 1
From: Richmond Ca
Re: 2002 c5 Knock in motor (123Gone)
If it is piston slap, it IS normal (if you don't have the new pistons.)
Thread Starter
Instructor
Joined: Nov 2001
Posts: 235
Likes: 0
From: Boca Grande Fl The Tarpon Capital Of The World Fl
Re: 2002 c5 Knock in motor (wwashing)
It does infact go away after warm up of 15 or 20 mins. If thats normal why do some have it some do not? vaka
Pro
Joined: Mar 2000
Posts: 690
Likes: 7
From: Bradenton, FL
Cruise-In II Veteran
Re: 2002 c5 Knock in motor (vaka)
Just for the record, both of our LS-1's exhibit some piston slap when cold, (way less than my L98 did). It goes away after about 30 seconds of operation however. Some of this is just a penalty for having a high performance engine with loose clearances.
If your car has a noticable knock after the engine begins to warm up (water temp hits 120 or so), you should be complaining about it.
If your car has a noticable knock after the engine begins to warm up (water temp hits 120 or so), you should be complaining about it.
Instructor
Joined: May 2001
Posts: 127
Likes: 1
From: Yorba Linda, CA,,,USA
Re: 2002 c5 Knock in motor (vaka)
Had the same problem on my 01. Seems that now it is not as pronounced with 6500 miles on it. I'm thinking it may be a ring seating thing. Perhaps the pistons are tracking better. I listened to several new C5s and they all sound somewhat different, but noiser than normal. You also have to remember that the aluminum block will transfer much more noise that a cast iron block. http://www.corvetteforum.cc/zeroimg/...Chevy_anim.gif
