Squeaking pulley?

[L-Mo99]

Another thing it does is when I turn the truck off it has a sound like it's winding down. Not sure if this helps with diagnosing but I haven't found any threads that mention it.

 

[Jason Rosie]

I have the exact problem on my 99 yukon, that's why I just joined. Exactly what you described, but mine almost sounds like it's coming from the bell housing. My tyranny shifts just fine but I suspect possibly a torque converter bearing. I'll check back to see what you guys say and I'll let you know what I find on mine.

 

[Jason Rosie]

Lois, is your noise a loud rhythmic screeching?

 

[Jason Rosie]

L-Mo, check this out... I've never seen this before. I lubed up all my pulleys and nothing changed, and I don't think the repetitive screaching is coming from my bell housing. My yukon came with a K&N intake on it and I hope yours does too because when I put my hand on the intake between the throttle body and the air filter and push it back towards the cab, tada! The metallic chirping goes away completely, even when I rev it up manually at the throttle body linkage. When I pull the intake forward towards the grille it comes back! I think I will go back to a factory intake. I think the metal breather tube that goes from the K&N intake to the passenger side valve cover rubs on a rocker arm or the cam. Will update soon, hope this helps

 

[L-Mo99]

L-Mo, check this out... I've never seen this before. I lubed up all my pulleys and nothing changed, and I don't think the repetitive screaching is coming from my bell housing. My yukon came with a K&N intake on it and I hope yours does too because when I put my hand on the intake between the throttle body and the air filter and push it back towards the cab, tada! The metallic chirping goes away completely, even when I rev it up manually at the throttle body linkage. When I pull the intake forward towards the grille it comes back! I think I will go back to a factory intake. I think the metal breather tube that goes from the K&N intake to the passenger side valve cover rubs on a rocker arm or the cam. Will update soon, hope this helps

I'm going to check this out today.thank you for the input.

 

[Holic]

I had a similar problem on my 99 LT 4x4 5.7, but mine chirped quietly from the start and got louder as the engine warmed up (if memory serves)... I changed idler, serpentine (twice), tensioner, a/c compressor (that needed replaced anyway), alternator (180). Nothing worked. Just before I lit the thing on fire, a mechanic down the street gave me a tip to change the serpentine "brand." I thought "yeah, sure." I was using the AC delco, but once I put a gatorback on it... No more squeek.

 

[L-Mo99]

L-Mo, check this out... I've never seen this before. I lubed up all my pulleys and nothing changed, and I don't think the repetitive screaching is coming from my bell housing. My yukon came with a K&N intake on it and I hope yours does too because when I put my hand on the intake between the throttle body and the air filter and push it back towards the cab, tada! The metallic chirping goes away completely, even when I rev it up manually at the throttle body linkage. When I pull the intake forward towards the grille it comes back! I think I will go back to a factory intake. I think the metal breather tube that goes from the K&N intake to the passenger side valve cover rubs on a rocker arm or the cam. Will update soon, hope this helps

I have a factory intake and tried messing with it a little to see if there were anything changes but that didn't work unfortunately.

 

[L-Mo99]

I had a similar problem on my 99 LT 4x4 5.7, but mine chirped quietly from the start and got louder as the engine warmed up (if memory serves)... I changed idler, serpentine (twice), tensioner, a/c compressor (that needed replaced anyway), alternator (180). Nothing worked. Just before I lit the thing on fire, a mechanic down the street gave me a tip to change the serpentine "brand." I thought "yeah, sure." I was using the AC delco, but once I put a gatorback on it... No more squeek.

Went with the gatorback and I thought reduced the noise slightly but after driving for a little while it's just as loud again.

 

[Contend997]

It sounds like you have a bad bearing in one of you pullies spray each with wd40 one at a time. Then the one that stops the squeak change