legalins

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

mike348

My sons truck 5.3 LS motor has been doing it for 200,000 miles and still going strong. My o4 has never done it.

1badf350

My 2000 coupe has done it since I bought it. Had 48k on it then, has 73k on it now. I'll let you know if it blows up.

RSchleder

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!

c5vetteski

the lifters are hydrolic so the need a few min to pump up with oil its normal to have this happen. 99c5

legalins

To ALL,

Thanks for the info. and feedback!

minitech

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.

tlc0706

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

dgrant3830

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.

minitech

Just to be clear. You say lifters in the LS1 are worn out at 32,000 miles?

SUPERCRUZ

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.

SUPERCRUZ

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.

dgrant3830

NO, they shouldn't be worn out that early. I must have mis-read it. Thank You for catching that.

Secret237

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.

itzza427

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!!!

BLOWNBLUEZ06

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.

30yrw8

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.

capevettes

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.

dieseldave56

According to John Joriga,GM Asst Chief Engineer for the Gen 3 engine ; cold piston slap has been an anomoly in some LS engines from 1997 and is not a durability concern. In mid April of 2001 GM addressed the limited number of complaints by reducing piston to cylinder wall dimension with new pistons that had a anti friction polymer coating on the skirts.

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.

legalins

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