Engine chattery when cold?
Thread Starter
Instructor
Joined: Oct 2008
Posts: 239
Likes: 10
From: Uxbridge Ontario
Engine chattery when cold?
Bought my first vette a couple of months ago, a 2000 coupe with 32,000miles on it. When I first start it up the motor is very chattery, the valves seem to be very chattery, this only last until the motor is warmed up, after that when the motor is warm it seems fine.
Is this normal?
Thanks,
Rob
Is this normal?
Thanks,
Rob
Melting Slicks
Joined: Nov 2006
Posts: 2,431
Likes: 3
From: Iowa City Iowa
Be happy,don't worry!
It's the nature of the beast! I almost didn't buy my 2000 with 38k miles till the dealer started up 4 other C5's and they ALL clicked away. My car now has 65k miles and runs like a champ. Forget about it and enjoy!
Safety Car
Joined: Mar 2007
Posts: 3,518
Likes: 37
One issue with the 2000 that was fixed in 2001 is a chattering noise "at garage maneuver speed" according to info from GM. I had that and it was sometimes embarrassing with the loud chattering when pulling up somewhere.
Can check for that by opening the hood and while someone else moves slowly looking at the top belt tensioner. It is the tensioner chattering.
GM fix is to install a better tensioner and an alternator with a clutch.
I fixed mine by just replacing the tensioner. Easy and about $35.00 from auto parts store.
Can check for that by opening the hood and while someone else moves slowly looking at the top belt tensioner. It is the tensioner chattering.
GM fix is to install a better tensioner and an alternator with a clutch.
I fixed mine by just replacing the tensioner. Easy and about $35.00 from auto parts store.
Safety Car
Joined: Jan 2007
Posts: 4,225
Likes: 0
From: The Great Truth: "There ain't no free lunch"
St. Jude Donor '08-'09-'10-'11
My truck is a 5.3 1999 Z71. Sounds like a diesel when it's cranked. Three or four minutes, noise is gone. 170,000 miles and still going
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Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Chances are the lifters are bleeding down when cold. When that starts to happen, they are simply wearing out. Nothing unusual about that as nothing lasts forever. Pull the heads and drop in 16 new ones, put her back together and go.
Safety Car
Joined: Mar 2007
Posts: 3,518
Likes: 37
Just to be clear. You say lifters in the LS1 are worn out at 32,000 miles?
Burning Brakes
Joined: Mar 2003
Posts: 1,156
Likes: 2
From: Arlington VA
Have you ever considered the possibility the noise is the dreaded piston slap issue so often discussed on this forum. You might try running a carbon depletion service on the car to remove carbon buildup on the tops of the pistons and backs for the intake valves. Worth a shot. I recommend using BG 44K . Run a can in a couple of tanks of fuel and see if this improves the issue. BG products are only sold in professional shops so you will need to visit your local garage or dealer to pick up a few cans. I run this stuff in all my cars every 7500mi to control carbon. If the previous owner never did anything to control carbon, good bet this may be contributing to your issue. Good luck with it.
Burning Brakes
Joined: Mar 2003
Posts: 1,156
Likes: 2
From: Arlington VA
I am going to make another recommendation to you that may also be of some help. If you have not changed the oil recently, change it out with a fresh supply of Mobile 1 5W30 or another high quality synthetic motor oil. Add a bottle of ZMax micro lubricant to the oil change.
The reason I say this is that I recenty had a H/C package installed on my 03. Car had a slight valve tick at 2200 RPM which is fairly common on a big cam car. No noise above that RPM or below that RPM. I drove the car that way for about 2500mi. I did my Fall oil change and decided to try the ZMax to see what it would do. Noise is gone. I am a believer and plan to put the ZMax in every year during my annual oil change.
Again, good luck with your issue. My recommendation are a lot cheaper than tearing into your motor or just living with the issue. Hope this helps you out.
The reason I say this is that I recenty had a H/C package installed on my 03. Car had a slight valve tick at 2200 RPM which is fairly common on a big cam car. No noise above that RPM or below that RPM. I drove the car that way for about 2500mi. I did my Fall oil change and decided to try the ZMax to see what it would do. Noise is gone. I am a believer and plan to put the ZMax in every year during my annual oil change.
Again, good luck with your issue. My recommendation are a lot cheaper than tearing into your motor or just living with the issue. Hope this helps you out.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
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From: Van Buren Arkansas
Wounded Warrior Escort '11
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
I understand that this may also be Injector noise, be sure where the noise is coming form, I have an A/C clutch making this type of noise, but only sometimes and for less than 30 seconds after it's started.
The ONLY good oil additive is something with Moly in it.
The ONLY good oil additive is something with Moly in it.
Last edited by Secret237; Nov 8, 2008 at 01:49 AM.
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
Have you ever considered the possibility the noise is the dreaded piston slap issue so often discussed on this forum. You might try running a carbon depletion service on the car to remove carbon buildup on the tops of the pistons and backs for the intake valves. Worth a shot. I recommend using BG 44K . Run a can in a couple of tanks of fuel and see if this improves the issue. BG products are only sold in professional shops so you will need to visit your local garage or dealer to pick up a few cans. I run this stuff in all my cars every 7500mi to control carbon. If the previous owner never did anything to control carbon, good bet this may be contributing to your issue. Good luck with it.
Yep piston slap might be in there,,,guess it depends how loud it is whether it is slap ,lifters or tensioner. At least in mine the slap is pretty subtle and goes away pretty quickly. Must admit this is my first motor with forged pistons and even though it was a faint sound it was a bit unnerving till I got used to it!!!
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
On my rice powered Mitsubishi, my lifters would tick. I took it to the dealer under warranty and they told me that it was obvious that I used tank oil from an oil change place. They told me to use bottled oil and it would go away. I thought it was total
, but when I changed to good bottled oil, it went away. I then began to learn how crappy the oil pumped out of the tanks really was. I highly recommend that no one ever uses oil from the tanks at oil change places in any vehicle they own.
, but when I changed to good bottled oil, it went away. I then began to learn how crappy the oil pumped out of the tanks really was. I highly recommend that no one ever uses oil from the tanks at oil change places in any vehicle they own.
Cruising
Joined: May 2006
Posts: 12
Likes: 0
From: Overland ark Kansas
I have a 2001 Coupe that has had the piston slap since new. It sounds horrible when starting on a cold day. Not a problem on warm summer days. GM extended my warranty to 6/60 on the engine after I complained. I have 50,000 miles and no issues, although the clattering continues on cold starts on cold days. GM told me this is normal and occurs in pickups and SUV's as well (they have extended warranties for those vehicles if you complain). They claim it should not affect the longterm reliability of the engine. These motors are also susceptible to carbon build up, so my dealer suggested I run a bottle of a GM carbon buster through a tank of gas a couple time a year. It seems to help a little. Even "spirited" driving doesn't seem to keep the carbon away, so I run the GM additive. Hope this helps.
CF Community Team
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Piston slap on an LS1 is not that uncommon nor is it a problem. When the engine is cold the pistons have a little room inside the bore. You don't want them too tight because once the engine warms up the pistons will expand. If you took two identical engines, one with some piston slap and the other without, the engine with the piston slap will probably make more horsepower due to reduced friction. Most race cars are built that way and they sound it when they start up. A little piston slap is nothing to worry about as long as it goes away when the engine is warm.
Drifting
Joined: Feb 2007
Posts: 1,993
Likes: 7
From: LaPine Oregon
Piston slap on an LS1 is not that uncommon nor is it a problem. When the engine is cold the pistons have a little room inside the bore. You don't want them too tight because once the engine warms up the pistons will expand. If you took two identical engines, one with some piston slap and the other without, the engine with the piston slap will probably make more horsepower due to reduced friction. Most race cars are built that way and they sound it when they start up. A little piston slap is nothing to worry about as long as it goes away when the engine is warm.
Joriga also added that GM had not seen a measurable hit from a power stand point because of the tighter tolerance and increased associated friction. GM addresssed this issue as a customer 'pleasabilty' becasue of the numbers of concerned customers. Like the reivised rings, the installation of the new pistons will not add any performance advantages.
This new piston was continuned thru the '02 M/Y.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 239
Likes: 10
From: Uxbridge Ontario
Thanks again to all for the replies and great advice. I think I will try a carbon depleter in the spring when I take it out of storage for the winter. This sounds like its fairly common and its nothing I should really worry about then, based on what I have read.
I can now rest a little easier knowing this.
Thanks again (what a great site)
Rob
I can now rest a little easier knowing this.
Thanks again (what a great site)
Rob