Another round of diagnose that noise?

[spotdog14]

New noise. Comes from the front end I believe, definitely engine. Only happens at highway speeds when accelerating at high RPM's. Its a squeal, I'm thinking either idler pulley or belt tensioner.

So far the alternator is working fine, but should I look into water pump pulley?

Anything else I should check?

Thank you.

**Edit**
Figured I should add a little more information, 130k on the motor, all original pulleys as well as alternator and water pump.

 

[Flexpedition]

Is the serpentine belt original as well? A/C tends to apply the most load, so does the noise happen with or without the compressor running? Any noise at all with the truck parked & hood open? Is there slack in the belt?

Although widely considered a band-aid solution, aerosol belt dressing does offer some advantages - tackiness on rollers, swell and conditioning of dry & stretched rubber, even if minor, and will buy some time until you have a moment to address the issue. I'd try a can of the CRC brand. If it yields no relief, then pulley and/or the tensioner would be the next logical points, along with a new belt.

I've read on a few Ford forums that (aftermarket) Gates belt tensioners are not as good as they once were, so my advice would be to use Motorcraftt. Gates does still make a good belt.

 

[spotdog14]

Is the serpentine belt original as well? A/C tends to apply the most load, so does the noise happen with or without the compressor running? Any noise at all with the truck parked & hood open? Is there slack in the belt?

Although widely considered a band-aid solution, aerosol belt dressing does offer some advantages - tackiness on rollers, swell and conditioning of dry & stretched rubber, even if minor, and will buy some time until you have a moment to address the issue. I'd try a can of the CRC brand. If it yields no relief, then pulley and/or the tensioner would be the next logical points, along with a new belt.

I've read on a few Ford forums that (aftermarket) Gates belt tensioners are not as good as they once were, so my advice would be to use Motorcraftt. Gates does still make a good belt.

Yes the belt is original as well. What my ultimate plan is if I decide one of the pulleys is the problem is to just replace both pulleys, belt tensioner and belt.

The belt is in good shape, no cracks, and the tensioner is working extremely well, I couldn't get it to move without really trying so no slack in the bet itself. With the truck in park and hood open I do not hear the sound at all (just your typical timing chain rattle). It also doesn't happen with city driving, or under 60 mph driving. Its only when going over 70 and then accelerating that I hear the noise. At the time the AC was off.

Thanks for the tip on aftermarket. I noticed there are a few brands and think I might just stick with Motorcraft.

 

[Gamecock]

I have a whining noise in my engine that just started. Had Ford diagnose while it was in for an oil change. Its a bearing in the alternator pulley. Unfortunately they say you can just replace the pulley and bearing. Want $900 parts & labor. LOL, no thank you. I find someone else to do it.

 

[Habbibie]

Check your idler pullies, those are usually the first to go out. Place your hand on them (while car is off obviously) and push, they should be firm without any clicking.