Help Identifying Chirp During Cold Starts
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,821
From: Charlotte, NC (formerly Endicott, NY)
I don't hear a chirp. I hear a loud rapid tapping noise. To tell if it is temperature-related pull up your Tour Display on the Instrument Panel where you can see both the coolant and oil temps in digital format to the right of the speedo. Start the engine and note both the coolant and oil temps when the tapping stops. Do this a couple of times to see if the tapping stops at the same temps. My C5Z had the typical LS engine fairly loud piston slap after a cold start but the noise would always reduce and stop when the oil temp approached and then reached 110 degrees. Your tapping is about twice as fast as my piston slap so I figure it might be caused by something in the valve train.
Bill
Bill
Burning Brakes
Joined: Jan 2023
Posts: 800
Likes: 353
Unfortunately I can’t answer your question but I have this same noise in cold start with my mustang. Had it in to the dealer to get it documented and they said it was the belt. I explained to them how this was obviously not the case but they insisted on changing it anyway. To their surprise the sound did not go away. I don’t drive the car much so I’m living with it for now but I’d love to find an answer. I swear it’s coming from a pulley…….
Safety Car
Joined: Jun 2004
Posts: 4,986
Likes: 393
From: Stoney Creek Ontario
belt chirp is common with a 7 - 8 year old belt... put a new one on and it'll probably cure the noise...
