Sounded like rod knock and then went away

Stroked777 · Oct 13, 2014

Mines a chirp and it's definitely coming from the front of the engine. To be exact the tensioner.

Stroked777 · Oct 13, 2014

Well did a little more digging and I can see the idler pulley on the alt. bracket is doing a lot of moving around. So atleast I found the culprit

Powerstroke Man 6.4 · Oct 14, 2014

I should check mine out soon LOL. Its starting to chirp again its only been 40K since the dealer changed the belt , tensioner and the idler pulley I wonder why its going out in short period of time? Its making the same noise it did when it went out last time.

Stroked777 · Oct 14, 2014

I had my pulley for the main drive replaced maybe about 50k ago and booth belts were done 40k ago along with the ac tensioner. But I now see it's the idler pulley that's right hinder the second altenator location that's bad

Stroked777 · Oct 14, 2014

So little update. Changed the pulley and the squeak is still there. I ruled out the entire main accessory drive by taking the belt off the balancer and the squeak was still there, that leaves just the AC drive, it's not the AC pump because the squeak is there pump engaged or not, leaving just the tensioner and the harmonic balancer. I sprayed so lube on the tensioner pully and that did nothing and it's not the arm it's self because it doesn't move at all. So now I'm leaving toward something behind the balancer. Is this possible that something behind it that making the sound? The sound starts when the engine is warmed up to operating temp? Could the oil deal leak I have do something with it? I never min the leak because is was never bad enough to leave a puddle on the ground or to make oil dissapear on the stick. What are your though one something behind the balancer causing the sound

May I add the belts are brand new at 75k and I'm at 113k now

webb06 · Oct 14, 2014

Stroked777 said:
So little update. Changed the pulley and the squeak is still there. I ruled out the entire main accessory drive by taking the belt off the balancer and the squeak was still there, that leaves just the AC drive, it's not the AC pump because the squeak is there pump engaged or not, leaving just the tensioner and the harmonic balancer. I sprayed so lube on the tensioner pully and that did nothing and it's not the arm it's self because it doesn't move at all. So now I'm leaving toward something behind the balancer. Is this possible that something behind it that making the sound? The sound starts when the engine is warmed up to operating temp? Could the oil deal leak I have do something with it? I never min the leak because is was never bad enough to leave a puddle on the ground or to make oil dissapear on the stick. What are your though one something behind the balancer causing the sound

May I add the belts are brand new at 75k and I'm at 113k now

Pull the AC belt off to completely rule out the compressor.

mandkole · Oct 14, 2014

spray a little water on the ribs of the belt. I dont recommend it, but Ive shot a mist of wd40 on the ribs of the belt also. if the noise changes at all, its the belt.

Stroked777 · Oct 15, 2014

What about a belt conditioner spray? but wouldn't a belt squeak all the time? And not just when the engine gets all the way warmed up?

Powerstroke Man 6.4 · Oct 15, 2014

I seem to have the same sqeak also when it warms up. Keep us updated.

mandkole · Oct 15, 2014

A brief shot of WD on the belt ribs wont hurt anything. It takes less and dries quickly so thats why I like it better than water for quick troubleshooting. No to belt dressing-- It was bad when it first came out for v-belts 40 years ago and it will quickly ruin a micro-v style belt.

Once the belt starts to chirp, it will do it forever. There is likely some misalignment in the components or slight mismatch in the pulley groove profiles that prematurely wears the belt. Its usually tolerance stack on the block casting bosses, the brackets, etc. Once the belt wears enough, it chirps.

When looking for misalignment, focus on the pulley spans that are very close to one another. Those are most sensitive.

Belt chirps are a very common troubleshooting complaint and a frequent source of belt specification discussion at OEMs.

Sideswipe505 · Oct 15, 2014

Yeah it can't hurt to test the belt out... I remember on a Corvette I had, it NEEDED gator belts, everything else would squeak. Drove me insane.

Stroked777 · Oct 15, 2014

Maybe I'll just throw a ac belt on it then. I replaced the idler pulley anyways because the old one was worn. Just weird that a belt would go bad with in 40k

mandkole · Oct 15, 2014

the belt would run for another 100k but it will be noisy. I tell ya we start new programs all the time and run the belt construction of the month looking for ways to cover up noise caused by a variety of things.