I have had my 2001 C-5 coupe for a year and a half now. Got it brand new. There are no alterations what so ever on the car. I have had the oil changed with Mobil One 5w30 4 times. I check my oil level very often my consumption is about 1 qt every 3500 miles. The vehicle has 22,000 miles. I drive in Texas on wide-open roads. Early on I noticed when the vehicle is first started and is at ambient temp anywhere from 30 to 100 F there is a tapping/clicking sound with a slight hint of rap from the bottom end of the engine towards the rear of the block more so than forward. This is almost characteristic to lifter noise. This noise can be heard from 30 feet away. Once the engine reaches operating temperature the noise goes away. Then if the car is parked for an hour and the oil cools off some, and the engine is restarted the same sound occurs again until operating temperature is reached once again. I had taken the car to the dealer at first sign of this at about 5000 miles. They let the car sit all day to cool off, then they ran it. They determined that this sound is normal and characteristic to an all aluminum engine and sent me on my way. As time has gone by it seams a little louder or I could just pay more attention to it now. I would like to know if this is normal as I know a few people with C-5's and they don't have this noise. I have asked other owners I have seen on the street as well and they don't have the noise. It seams to do a disservice to the character of the car when you walk out side at a public place and get in and entertain onlookers with rap-tap-tap-tap-click-rap-tap-tap-tap..... My other dilemma is when driving the car below 50 degrees F the front suspention creaks all the time when going over mild dips. If it is over 50 degrees there is no creaking at all. The car does have the STOCK performance suspension package, which I believe employed stiffer springs and a power steering cooler. The car has the active handling but not the adjustable shocks. Has anyone else experienced this or have knowledge to this and is it normal or what needs to be done. Thanks for your help on both issues. :skep:

 

some noise is normal but hard to know unless someone listens. Take it to a tuner and let them listen. Hard to describe noises with words. Should not really hear noise with the stock suspension. Listen to someone elses car that is stock. Any Vette guys near you on the forum hook up and compare. Also welcome to the forum :D :seeya

 

As noted above, it's hard to diagose a problem without hearing it. It makes sense to let a local tuner who's familiar with these have a listen.

Have you read this article? It may be of interest....
http://www.idavette.net/hib/02ls6/page5.htm

 

My 01 had a lifter go on it and so did a friend, in his case they tought it was comming from the bottom end. If this is it then they will change the cam and the lifter if not take it all out and clean it.

:chevy :chevy

 

Again it is hard to tell from your description how bad your noise is but my 97 has made a similar type of noise for the last 5.5 years. Its especially noticeable when I pull the car on the trailer and stand by it with the engine running. All I have to do is bend over a little and I can hear the noise coming from under the car. At first I thought it might be a bad rod bearing but after listening to quite a few other people comment on the subject I'm pretty it isn't. Otherwise, I would have blown it up at one time or another while accumulating the several thousand track miles the car has on it.

The suspension squeaks are from the composite springs. This is the second Vette I have had with the same noise. My 86 did the same thing. Depending on temperature the squeaking should go away after you drive the car for a while. It might last 15 or 20 minutes in the 30 to 35 degree range while at 0 degrees it might last until you put the car back in the garage.

Bill


[Modified by Bill Dearborn, 10:37 PM 1/28/2003]