Crazy screeching noise from '03 6.0

[tungsten]

Only happens when it’s cold. Like really cold -15c. I suspect the water pump. What say you?

 

[Doubeleive]

Only happens when it’s cold. Like really cold -15c. I suspect the water pump. What say you?

Exhaust leak+ noisy tensioner

 

[tungsten]

Exhaust leak+ noisy tensioner

Both tentioners just replaced,yes exhaust leak I know.Whats the screeching noise?

 

[tungsten]

I suppose one the new tension pulleys could be it?

 

[tungsten]

I replaced them when it was warm.both were noisy. Now that it’s cold the noise is here.
Crazy sound. I guess I could remove the a/c belt and see for starters.

 

[Doubeleive]

I replaced them when it was warm.both were noisy. Now that it’s cold the noise is here.
Crazy sound. I guess I could remove the a/c belt and see for starters.

sometimes the ac tendsioner's tend to be noisy when it is cold out even if brand new
try taking the ac belt off before you start it in the morning and see what it does
my 03 did that and it was annoying as hell

 

[MassHoe04]

Something on my belt/pulleys squeaks slightly once in a while.
Usually on cold start in the mornings and it is wet or very humid out. Squeaks a couple of minutes and stops. PO said it has always done that. My mechanic was not concerned over anything he saw with condition of any belts or pulleys.

 

[tungsten]

sometimes the ac tendsioner's tend to be noisy when it is cold out even if brand new
try taking the ac belt off before you start it in the morning and see what it does
my 03 did that and it was annoying as hell

Just removed the a/c belt,had to pull it into garage for heat.Backed it out now letting it sit in the cold. 5f right now brrrr

 

[Doubeleive]

Something on my belt/pulleys squeaks slightly once in a while.
Usually on cold start in the mornings and it is wet or very humid out. Squeaks a couple of minutes and stops. PO said it has always done that. My mechanic was not concerned over anything he saw with condition of any belts or pulleys.

ya that's pretty typical, I think that's why gm did away with the ac tensioner and went to a stretch belt

 

[tungsten]

Ok so started it again no noise. Yay.
Took it off gave it a spray and didn’t tighten the pulley bolt so much as it was pretty tight. Got it back on will see what happens.
Thanks

 

[OR VietVet]

I had same noise last winter and was belts. Can I ask, unless the belts way way new, why did you not do all tensioners, idlers and belts at the same time? What am I missing?

 

[tungsten]

I had same noise last winter and was belts. Can I ask, unless the belts way way new, why did you not do all tensioners, idlers and belts at the same time? What am I missing?

As far as I know theres only 2 idlers,replaced both.The main one is super easy takes 2 minutes.The a/c one is kinda a ***** if truck isnt jacked up.Im a big guy,as far as belts go Im cheap lol.

 

[OR VietVet]

Replace them now, you cheapskate and use good quality belts and splurge a bit.

 

[tungsten]

Replace them now, you cheapskate and use good quality belts and splurge a bit.

You know maybe its the belt and bearing making the noise? Crazy sound for a belt to make though.Ill stop and get new ones one day.At least now I know what it is I think.Didnt drive it with the a/c belt just hanging behind the main belt.Was scared it would get tangled up.

 

[OR VietVet]

I only experienced the problem in the cold and was not as cold here and I thought at first it was a vacuum leak. Two days of search and destroy led me to the belts. Took me two days because the temp was not as cold and was hard to duplicate the noise any longer than 1 minute at a time.

 

[tungsten]

So what is the function of the a/c pump in winter?

It comes on when defrost is engaged.

 

[Doubeleive]

So what is the function of the a/c pump in winter?

It comes on when defrost is engaged.

it acts as a dehumidifier

 

[tungsten]

it acts as a dehumidifier

Thats what I thought,My last truck had no belt ,it broke so I just left it until summer.Didnt have any issues,probably save on gas.
Humidity is not an issue here.

 

[Fless]

It's best for the a/c pump to run periodically all year 'round. There's a better chance for the seals to stay good.

 

[DBacon]

I had a similar problem years ago on a small block Chevy, due to misaligned pulleys.
As the serpentine belt traversed across the smooth tensioner pulley it was dragged sideways just 1/8". I had to move the alternator back 1/8" and it was finally quiet.
I discovered this by putting straight tubing in the grooves of the pulley before and after the tensioner pulley, and they didn't line up. I used carbon fiber tubing, about 4mm OD from my model airplane construction supplies.
It bugged me for years screeching on cold startups.