Brown residue near alternator??

I have a '22 with 25K miles and noticed this brown residue near the alternator. It appears to be coming from the accessory belt. It does not wipe off easily and I am certain it is not road dust or grime.

Has anyone seen this on their truck and know what the cause is? The belt appears OK but is it?

I have owned many vehicles and never seen anything like this.

TIA.

 

Looks like it was submerged in some muddy water. The residue on the alternator body does not make it seem like that is where it is coming from. Especially because the belt is coated entirely on its surface not just the edge.

 

Looks like the belt is rusted. The rubber top layer is gone. Even the nut is rusted. Dust or mud inside the tensioner

 

Thanks but, nope, not muddy water. It is like a brown dust or powder. It wipes off but not easily. Truck has never been through a puddle or off road other than a few dry dusty gravel roads and my gravel driveway. The only place the residue is is around the alternator.

 

It does look like the top cover may be gone, but I think the belt has a fiber reinforcement, not metal.
It almost looks like something has been dripping on it, the way those “sling” marks go across the alternator. I’d follow the belt around and look elsewhere.
Just a guess.

 

Check out your lower idler pullies. Sure looks like rust getting transferred to the belt. I alternator is sucking in the dust making it look worse there.

 

Taste it. Does it taste like rust or ink from printing on belt?
Only way to find out.

 

I would guess the residue could come from the A/C clutch then into the smooth idler pulleys impinching it onto the belt. The alt shaft looks a bit rusty. That belt looks rough not shiny which is odd

 

The rust is even on the lower hose. I would follow the belt and find the source. It does not look like the alternator. Good pick up though. Some people never look under the hood. Was there a reason you looked?

 

thank you. i know it resembles rust but i am certain it is not. i live in an arid area, no salt is used on the roads, etc. and there is no rust on any metal components elsewhere including the frame. it appears to be something coming from the belt. as i posted above, it is does not wipe off easily and i attached another photo of the area.

there are no squeaks or unusual noises at any time, and the truck is unbelievably quiet when idling. i have no performance issues or signs of fluid leaks anywhere.

as for how i noticed it, i take a look under the hood every week or two and check the oil. i first noticed it maybe a couple months ago and at the time thought it was just dust of some sort but is has gotten worse.

i do not live close to a dealer and dread the thought of taking it to them. i may stop by an independent shop that i trust and see if i can get their thoughts.

 

While I won't go as far as to taking a guess as to the cause, or it it's even an issue, I'm gonna go ahead and say the belt itself is the source.
If you don't see any other obvious signs or symptoms, I'd throw $50 bucks at a new belt.

2018 for reference..

 

The white stain looks like salt residue on top of the radiator shroud and on the vvti cover

 

A new belt is cheap, replace that one and eliminate it as a source. Not a bad thing to have on hand.

 

it is not road salt. i am on a well, and there are minerals in the water. that stain is from when i recently washed my truck.

 

Where do you live ?
What it looks like is it went through a salt bath at some point ,then sat and some exposed bare metal pieces got rusty.
Do you have a water softener?

 

as i posted above, the truck has never been exposed to salt and there is no rust anywhere - frame, welds, leaf springs, etc. are rust and mud free. it is not rust and i do not have a water softener.

 

There’s rust on the alternator bolt so there’s rust elsewhere also…..

 

how do you suppose the rust got evenly distributed on the belt and pulley?

 

I agree with these 2 . Maybe it’s just the belt itself . Defective

 

Rust from fine shavings. Something is/was rubbing. All it takes is a little bit of moisture/dew and those shavings rust up in an hour or so. Could be a pulley, bearing, etc. you’ll have to look around