2000 engine knock on startup when cold
Thread Starter
2nd Gear
Joined: Feb 2008
Posts: 2
Likes: 0
2000 engine knock on startup when cold
When cold, upon startup and in gear there is a noise like a bearing knock. Knock goes away after 2 or 3 blocks. noise seems to be gettting louder. I park the car on a slight incline with front end down. Have taken to dealer several times and never here this knock. Does anyone know what this might be?
Burning Brakes
Joined: Jul 2004
Posts: 932
Likes: 0
From: Las Cruces New Mexico
I have a 2000 coupe with A4 and hear the same thing until I get out of the subdivision. I have read on other posts that for our year model it is common (don't remember why though) and almost everyone who had the problem said the noise went away after it warmed up a little. I did not do a search but if you type in engine knock on the search you will find a lot of posts about it.
Racer
Joined: Jan 2007
Posts: 303
Likes: 0
From: Tulsa Ok
I have a 2K vert and its made that same knock sound since I bought it 2 years ago seems to be worse when I get close to oil change time. I think this is whats refered to as piston slap and they all do it. Bassspring
6th Gear
Joined: Jun 2001
Posts: 6
Likes: 0
From: Leland NC
My 2000 Vert also knocks on cold startup. But knock only seems to last about 2 blocks, maybe a minute or less. I suspect it is piston slap which I have heard is a common problem, but not a serious one. Otherwise the car runs great. I'm considering going to 10W-30 Mobil-1 on my summer oil change to see if that makes a difference. Box stock auto ran 105 / 13.7 1/4. Uses no oil & seems OK otherwise.
Burning Brakes
Joined: Mar 2006
Posts: 750
Likes: 82
From: Bedford IN
Doesn't sound good. I have a 99' with 108000 and have never heard this. I don't think that I would write it off as "Common". Not with a knock that sounds like a rod. Are you sure it isn't valve train noise?
Pro
Joined: Sep 2007
Posts: 735
Likes: 7
From: Bucks County Pa
Who's That Knocking
Hi, I've heard that quite a few of the c5's up to 2001 have a tendency to make a tapping or knocking sound, some from day one, on first startup of the day. My 03 doesn't but my 02 chrysler 300m has a tendency to . To me it sounds like valve tapping. I found that using a much better OIL FILTER with a good check valve in it cuts down on it dramatically, to the point that I seldom hear it anymore, going back to a lesser filter brings it back again. Don't know if that will work for the vette , but it's worth a try. Although it may be piston slap. I read somewhere that GM redesigned the piston skirt after 01.
Good Luck.
Good Luck.
Last edited by bestvettever; Feb 25, 2008 at 11:49 PM.
Drifting
Joined: Jun 2002
Posts: 1,945
Likes: 41
From: Corinth TX
Sounds like the notorious piston slap. Mine has had it for it's entire life. There is/was a TSB on this I believe. I think GM had a problem with their trucks doing the same thing but I can't recall off hand. My friends cars all have this as well. I have noticed that it changed depending on the oil I used. But then again that could have been attributed to my steady loss of hearing.
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Drifting
Joined: Feb 2007
Posts: 1,993
Likes: 7
From: LaPine Oregon
read and be of good cheer......................
Very common, not to worry. Read:http://forums.corvetteforum.com/show....php?t=1950088
Advanced
Joined: Mar 2006
Posts: 70
Likes: 0
From: Bellefonte PA
All I hear from mine is a tapping on cold start that sounds like valvetrain noise. My last car was a DOHC that I put heavier valve springs and Ti retainers in, so im used to lots of valvetrain noise.
Burning Brakes
Joined: Mar 2006
Posts: 750
Likes: 82
From: Bedford IN
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
pistonslap.com.
most of the c5s as well as other GM engines have it and it is perfectly normal.. Its the nature of the beast. goes away after engine is warmed up.. I noticed mine after 3 months, Most people will say they don't have it but have never really paid attention to the issue or are in denial. The issue was supposedly resolved on 2002 models, however many folks still report piston slap. The noise is irritating but I have just learned to live with it for a few minutes.. the borla stingers help too!!
most of the c5s as well as other GM engines have it and it is perfectly normal.. Its the nature of the beast. goes away after engine is warmed up.. I noticed mine after 3 months, Most people will say they don't have it but have never really paid attention to the issue or are in denial. The issue was supposedly resolved on 2002 models, however many folks still report piston slap. The noise is irritating but I have just learned to live with it for a few minutes.. the borla stingers help too!!
Drifting
Joined: Feb 2007
Posts: 1,993
Likes: 7
From: LaPine Oregon
John Juriga; GM Engineer for the LS1/LS6..........
..........stated at a press conference at Irwindale in 2002, that because of a limited number of customer complaints , a new piston was introduced to production in mid April of '01 that resolved the issue. This piston has a anti-friction coating ( the first Gen 3 engine to use this technology ) and that the pistion to bore tolerance was reduced. No measureable power loss was seen. Addressing the piston knock anomoly was more to please the possible complaints rather than being a performance or durability issue.
As with most all advances, Corvette leads the way to passing technology to the rest of the GM line , as most GM truck engines now enjoy this same anti-friction piston design.
As with most all advances, Corvette leads the way to passing technology to the rest of the GM line , as most GM truck engines now enjoy this same anti-friction piston design.
Racer
Joined: Aug 2007
Posts: 497
Likes: 0
From: Monrovia California
my duramax knocks my tahoe did it and my 01 c5 does it slightly when very cold also slight lifter noise. All said to be "normal" my nephew works for GM and has stated that the c5 is normal per his profession ASE certified monkey. His fix is to crank up the tunes for first 2 miles of driving then lower to comfortable listening level.
