Chirp, Chirp, Chirp.....:(

[lamerem]

Been a while since I last posted, but I have a head scratcher..

2011 Tahoe, 5.3 Flex, VIN 0, 105,000 miles. It has this little annoying chirp, chirp, chirp sound coming from the engine compartment. The noise is intermittent, and speeds up with the RPM's. Sometimes it is not there when the engine is cold. Here is what I have done so far:

• Removed the belt, ran the engine...no chirping sounds.
• Replaced the idler pulley as it had some play in it.
• Replaced the entire belt tensioner assembly (2 years ago the dealer replaced this).
• New belt about a year ago, Dayco Premium.
• I used a little WD-40 on the alternator shaft, no change in the noise.
• I sprayed a little WD-40 into the holes on the front of the Water pump pulley, no change.

I really feel it is the water pump, but I know that noises project all over in the engine compartment. Last year while getting new tires at Firestone I asked them to investigate it. Their response was that it was the alternator, of course they wanted to replace it. I asked them to get a new GM part and they said they use NAPA, nope sorry. I am not snobby, but I learned along time ago to only replace parts with OEM new from ACDELCO. That being said i don't go to the dealer, I get the part number and source it online. So I passed on their offer, and that brings me to today. I am hoping someone with a similar issue can point me in the right direction here.

 

[Fless]

@lamerem, I think that's pretty typical of the Vortecs, having the belt chirp. Had the same issue when I picked up my '04 Hoe early last year. It came with no useful maintenance records, and one of the things I did right away was change the tensioners and belts. Used the Gatorback belts (I think they're called Continental Elite Poly V now). Cured the chirp.

One other thing -- when I had the belts off I cleaned the pulleys, new and old. And replaced the idler pulley too.

 

[lamerem]

I guess maybe it could be the belt, that would make me a lot happier. Is there anyway to test the theory before buying one? I know back in the day we would spray dressing on it, but I've read that we can't do that on these new serpentine belts. Someone also said try baby powder on the belt, that sounds like a joy when the fan kicks on.

 

[Doubeleive]

or you could just loosen the belt and spin the alternator by hand and see if it that is the source of the noise or not, ditto for anything else that can turn by hand.

 

[lamerem]

I've turned them all by hand and nothing noticeable.

 

[Doubeleive]

well if this doesn't stop the squeak then its definitely hardware
https://www.walmart.com/ip/Prestone...35&wl11=local&wl12=16817510&wl13=5231&veh=sem

 

[HiHoeSilver]

Mine is the AC tensioner.....

 

[Doubeleive]

 

[lamerem]

Mine doesn't have an AC tensioner. The AC belt is a pain to change too. But, FLESS got me thinking about belts. I may just invest in the Continental Elite/Gator-back belts. They make one for the AC that stretches for installation and then firms up once installed. It has had great reviews. They look like quality belts as well. I think I will do the water test to see if the chirp goes away. I am not really into cracking the cooling system open to change the WP if I don't have too. That being said, if it was the WP it would facilitate a nice new coolant change. Ugh, I hate winter vehicle repairs...

 

[kbuskill]

You can try the old bar of soap on the belt with the engine running trick.

Alternatively, you should check to make sure all your pulleys are lining up. Sometimes people change out things like the power steering pump and don't get the pulley lined back up correctly with the other pulleys and it will cause this squealing/chirping noise.

 

[lamerem]

I've owned the truck since new, and there haven't been any other repairs. This noise just started one day, not sure why. Can pulleys get out of alignment?

 

[kbuskill]

I've owned the truck since new, and there haven't been any other repairs. This noise just started one day, not sure why. Can pulleys get out of alignment?

They shouldn't unless the bearings are failing and letting the shaft walk.... but if that is the case then you obviously have bigger problems.

It was just a suggestion of something that is often overlooked. I was unaware that you were the one and only owner so I thought perhaps something may have been changed without your knowledge.

 

[swathdiver]

Get a long extension or breaker bar and use it as a stethescope while the motor is running and chirping. As a young man I was just learning the importance of fuel pressure when my engine started making a chirping sound, melted two pistons! The next time I done did it deliberate, no way was I going to lose a race to some poser in his RX-7, we both kept turning up the boost until his exploded and mine melted only one piston this time. I drove that baby home 60 miles and had a new piston installed after work the next night.

 

[iamdub]

James said it- get or "make" a stethoscope. I bought a cheap mechanic's stethoscope from Harbor Freight years ago and it has saved me tons of frustration. You can remove the belt and spin pulleys all day, but it's very difficult to replicate the lateral load the belt places on those accessory's bearings, which may be the source of the noise.

 

[kbuskill]

Kinda off topic, but not to far... I learned something today. I was unaware that the newer trucks don't have a tensioner on the AC belt... my 08 does but I guess they changed up sometime later.

 

[lamerem]

Well I think I made some headway in the area of diagnoses. I ran the truck and put a little water on the main belt, chirp noise went away. So that tells me the belt is glazed, or out of align. Interestingly enough it was cold out and I had the defrost on, as soon as water hit the AC belt it was slipping like a deer on ice. So on the to do list, new AC belt, new main belt, and possible a tensioner for good measure.

I am looking at the Continental Elite (GatorBack) belts, any opinions?

 

[iamdub]

Kinda off topic, but not to far... I learned something today. I was unaware that the newer trucks don't have a tensioner on the AC belt... my 08 does but I guess they changed up sometime later.

I think '09+. My '13 Express work van shredded the A/C belt when a pebble lodged itself in a groove on the pulley. I had the passenger side of the van up on a curb in an Autozone parking lot and was trying to wedge it on with screwdrivers. It wasn't gonna happen. I drove the 4 hours home in 90+ degree heat with the windows down (loud as fcuk in that van!). I had a shop slip it on in 10 minutes the next day with the required special tool.

At the time, I still had an accessory drive bracket from a Gen3 (tensioner A/C setup) in my garage and I swore I was gonna swap it on my Tahoe that weekend if it had the rubber band belt setup.

 

[iamdub]

Well I think I made some headway in the area of diagnoses. I ran the truck and put a little water on the main belt, chirp noise went away. So that tells me the belt is glazed, or out of align. Interestingly enough it was cold out and I had the defrost on, as soon as water hit the AC belt it was slipping like a deer on ice. So on the to do list, new AC belt, new main belt, and possible a tensioner for good measure.

I am looking at the Continental Elite (GatorBack) belts, any opinions?

Can't go wrong with that one. I recently replaced both of my belts and used Gates K040378 and K060935.

 

[Doubeleive]

Kinda off topic, but not to far... I learned something today. I was unaware that the newer trucks don't have a tensioner on the AC belt... my 08 does but I guess they changed up sometime later.

I thought all of the 07-14 had no tensioner?, maybe if yours starts squeaking you can delete it and just use the new belt?
the one on my 2000 squeaked when it was cold out and my 03 Silverado does now also.

 

[kbuskill]

I thought all of the 07-14 had no tensioner?, maybe if yours starts squeaking you can delete it and just use the new belt?
the one on my 2000 squeaked when it was cold out and my 03 Silverado does now also.

Nope... my '08 Suburban LTZ has a tensioner on the A/C belt and I certainly plan to keep it that way. Seems idiotic to swap to a different style belt that requires "special" tools when there was nothing wrong with the old style.