"Chirp" on shutdown.

[TurboTahoe]

Hi guys,

On the Tahoe the engine does a 'chirp' noise right when shutting down. There is no 'run on' or anything of that sort (i.e. it doesn't keep turning...), but it does give an audible chirp when I shut it off. The Suburban doesn't do this at all.

Can you guys hazard a guess as to what it might be?

Thanks,

Rob

 

[turboaudi]

mine does it when the belt wears i think my tensinor is weak pull your belt & see if it goes away

 

[bison]

Alternator and tensioner idler pulley are good candidates

 

[ak diesel driver]

my dads and my brothers cummins both do it everytime

 

[BigBlueChevy]

I "X3" checking the tensioner. Usually what happens there is the spring in the tensioner becomes weak over time and is unable to keep the belt at the tension its supposed to. So when you take all your accessories that are turning at various RPM's and bring them to that sudden halt, the belt slips on the crank pulley giving that chirp.

 

[schiker]

I'd say belt too. That is the only thing that can chirp I think. For me anyway seems the tensioner always stretches a belt out eventually and I look for a belt with good grip or nice thick and soft rubbery back side to reduce any chirping/squeal.

 

[tanman_2006]

My 93 has the tensioner squeak everyone is talking about.

My 95's turbo had a bearing out and was squeaking on shut down just after i bought it. Stole the turbo off my 94 and installed injectors and glows, all better! I wish i woulda know about the ATT when I had the problem.

Hope you just have a belt problem!

 

[iamdave0887]

Neither of my trucks do it. My pickup used to clunk when being shut down. That ended up being the crank pulley. A new one solved that issue.

I'd look of the crank pulley and all the other pulleys for play/looseness with the belt off, or any strange noise when spinning(dry bearing, etc). If anything it'll help you rule each item out.

 

[WarWagon]

I put a bigger CS-144 alt on my 6.5's and it chirps the belt on shutdown. They make roller clutches on alternators to allow them to spin down and not chirp the belt. 2008 Duramax's have them IRC.

Check the dampers! Harmonic balancer and the rubber belt damper for the crank pulley.

 

[Crankme69]

My truck does it, on mine it's from the down pipe

 

[TurboTahoe]

I put a bigger CS-144 alt on my 6.5's and it chirps the belt on shutdown. They make roller clutches on alternators to allow them to spin down and not chirp the belt. 2008 Duramax's have them IRC.

Check the dampers! Harmonic balancer and the rubber belt damper for the crank pulley.

To be honest, that's what I was concerned about, that the harmonic balancer might be going out. I'll do the usual visual inspection.

Thanks for all the hints and suggestions.

Sincerely,

Rob