2003 Excursion V10 76,000 miles w/ some up north salt exposure. A few weeks ago I would notice a faint squeal / high-pitch whine while driving through the neighborhood on my way to work everyday - but it would quit by the time I got to the open road. Today, the squeal was much worse and kept at it all the way to work at all speeds. I turned off the A/C - still there. The pitch of the squeal goes up and down with engine speed. And will do it in park. Under a good load (if I'm accelerating quickly), it will go away. Over the weekend, I rinsed off the motor and it seemed to make the issue worse. I have a new tensioner pulley and idler pulley on order but I might try shooting a little wd-40 on them to see if the noise goes away until the new pulley's arrive.

Any other thoughts?

 

Noise sitting still idling? Have to be moving, could be a brake pad. Dont hear it over noise when accelerating.

 

very faint while sitting idling - when I press the accelerator with the truck in park, it get's much louder changing pitch with engine speed.

 

Did you check the little rubber elbow that is attached to the front of the throttle body? They can get a small "crack" right in the bend and cause a whistling sound.

 

I shot the centers of the idler, alternator and tensioner pulley's with PB Blaster and took the truck for a spin - no whine. If it goes a couple more days without the noise, I think it's safe to assume it's one of those (which would be a huge relief!)

 

When I first got my truck it had a similar noise. I suspected the tensioner pulley, but my dad squirted some Windex on the belt and the noise went away. (Windex works as a temporary lube and evaporates with no residue.) I replaced the belt (which was cracked anyway) and the noise has been gone since.

If you do replace your belt, I recommend Amazon. They have it for $30.11 and no shipping for Prime members.

They also have the tensioner for $43.38.

 

You still here?

 

The bearings on the idler and tensioner are both replaceable and stock bearings, at least on my 04'. So you do not have to buy the entire pulley assembly. I actually removed the rubber seal on both bearings and greased them around 40k miles.

 

The pulley's aren't that expensive - but good info for future bearing replacement preventive maintenance.

The serp belt only has 2k miles on it so I assume it's one of the pulley's - the noise hasn't returned. Should be getting my new pulley's installed soon.

Thanks for your help.

 

Removed and replaced both tensioner and idler pulley's. I put the old tensioner pulley on my finger and spun it - felt like there were rocks in there in lieu of bearings. Noise gone, happy owner.

 

Good deal!

 

Gotta love the simple fixes.

 

Good to hear it's fixed.

Over the years that I've had modulars, every few years I hear the tensioner or idler pulley bearings making noise - so I just replace the entire thing, and the belt while I'm at it.

Now that I have a real hydraulic press, next time I'm going to find some heavy-duty bearing the right size and see what I come up with...