Cold Start Chirp

[bgrif005]

I have a chirp coming from the rear of the engine on cold start up. When i say cold start up, i do not mean its cold outside, just that the engine has cooled down completely since last driven. the sound is barely heard in the engine bay, but can be heard more from under the truck - sounding like its coming from the oil pan or where where the tranny and engine meet. lower the rpm's the more the chirp can be heard. in idle you can hear it the mostits not loud or anything and not a squeal, just moderate chirp. once the engine takes 2 or 3 mins to warm its gone.

 

i have already had it at the dealer and the replaced serp belt - said the PS pulley was out of alignment and the serp belt was fraying and needed to be replaced. however, this did nothing for the chirp.

 

any ideas?

[bgrif005]

no ideas?

[VMax2007]

Bird nest?

[68haywagon]

I have a similar problem among others. The truck is at the dealer now. I'll get it back on Tues and I'll find out if they fixed it.

 

Mike

[bgrif005]

I have a similar problem among others. The truck is at the dealer now. I'll get it back on Tues and I'll find out if they fixed it.

 

Mike

 

 

did they say they located the problem? or are you still in the dark?

[fbachman]

Mine does that too.... I noticed on mine that I get it with the AC on (engine cold), and it goes away when AC gets turned off). Mine isn't BAD --- it's just noticable. IT was also hard to figure out what side of the engine it was eminating from.

 

IT almost sounds like a chirping belt, or pulley. At first I was paniked and thought it was the dreaded lifter noise --- but after further investigation, mine clearly doesn't sound like tapping lifters.

 

Please let us know what they find...

[pckhalil]

I've got a similar noise that I only hear when both the engine and outside temp are cold. It's definitely coming from the lower, rear part of the engine.

[Nick The Great]

It's probably not this, but

 

http://www.gm-trucks.com/forums/index.php?showtopic=48960

 

My 99 Chevy RCSB would do this. It seemed like it would only do it if the outside temperature was ~50° or less. After the engine warmed up, it would stop. I would spray belt dressing, and I also tried penetrating oil. Both helped the squeak. The mechanic got pissed when he found out. But that's another thread . . . Eventually they replaced the belt and idler pulley. I had them do this while they were replacing my starter. (Separate Issue)

 

But my 2007 Chevy CC does this a little bit too. Someday once it's nice out, I'll probably try the above mentioned thread. Again, sorry if this isn't what you're looking for.

 

[bgrif005]

do these new generation GM engines have timing belt or chain? could that squeak/chirp? thats where the sound seems to be coming from.

[VMax2007]

do these new generation GM engines have timing belt or chain? could that squeak/chirp? thats where the sound seems to be coming from.

 

Timing Chain. All Cam-in-Block (non-OHC) GM engines have timing chains.

[bgrif005]

do these new generation GM engines have timing belt or chain? could that squeak/chirp? thats where the sound seems to be coming from.

 

Timing Chain. All Cam-in-Block (non-OHC) GM engines have timing chains.

 

 

 

well i guess a chain couldn't make that noise.

[bgrif005]

I have a similar problem among others. The truck is at the dealer now. I'll get it back on Tues and I'll find out if they fixed it.

 

Mike

 

 

Mike,

 

Let me know what happened when you get it...cause and fix.

[bgrif005]

sorry to bring this up again, but the noise is continuing to get a little louder and sticking around longer after start up.

 

update: took a screw driver (using it as a stethescope) and found that its not the tranny, not the fly wheel, but seems to come directly from something above the fly wheel though. I just can't figure it out. I can hear the sound more prevalent fromt he driver's side fender than the pass side. This sound is just like a belt going bad, but the sound is not coming from the belt at all. another thing i notice is when the tranny is in park and i drop it into D or R and the rpm's drop 50 rpms or so the sound gets louder.

 

I am going to take it back to the dealer soon, but they dont seem to be very good at locating the sound since it only happens on cold starts and only lasts for 2-3 mins, so iam trying to give them a few places to look.

 

Mike, did they fix your problem?

[gvbhunt]

sorry to bring this up again, but the noise is continuing to get a little louder and sticking around longer after start up.

 

update: took a screw driver (using it as a stethescope) and found that its not the tranny, not the fly wheel, but seems to come directly from something above the fly wheel though. I just can't figure it out. I can hear the sound more prevalent fromt he driver's side fender than the pass side. This sound is just like a belt going bad, but the sound is not coming from the belt at all. another thing i notice is when the tranny is in park and i drop it into D or R and the rpm's drop 50 rpms or so the sound gets louder.

 

I am going to take it back to the dealer soon, but they dont seem to be very good at locating the sound since it only happens on cold starts and only lasts for 2-3 mins, so iam trying to give them a few places to look.

 

Mike, did they fix your problem?

my 2005 Silverado did that when it was cold outside. I figured out that it was the bearings in the starter going out. When there was no load on the starter (i.e. right after the engine started and the bendix released) it would squeal until it stopped turning. Try your little stethescope tool there.

 

edit...Sorry, just saw the 2-3 minutes thing. Probably not the same thing but if it only lasted for a second, that would be my guess.

[saxdogg]

This is probably not helpful, but I think a prev poster has the right track...I think it's the ac compressor coming on at startup. I've had a few cars (not gm) that did this as well. Heard mine do it the last three days...