Mysterious metal on metal squeak

[silverhawk184]

Hello,

I have a 97 Ranger that, despite it's age, has been going strong.
For the past while, it has had a mysterious squeak.

It only happens when it is up to temp (45mph+ for a few miles).
I have ruled out it being a wheel/drivetrain bearing as it has occurred at the drive through window.
I have ruled out it being an engine bearing as it still happens when I cut off the engine while coasting down the road.
I have ruled out it being a transmission bearing as when I preform the engine test, and put it in neutral, it still squeaks.

I am at a loss as to what it could be. My best guess is an exhaust bracket gets loose when it is hot and then makes noise. I have not been able to wiggle it while cold and get a squeak out of it though.

Does anyone have any idea on what to look for?

Thank you in advance.

 

[telsar]

Perhaps its the idler pulley or tensioner pulley for the drive belt.

 

[RayInStl]

Perhaps its the idler pulley or tensioner pulley for the drive belt.

He said it still happens with the truck in neutral and the engine off while coasting. The engine would not be turning in this instance.

Where does the sound seem to come from? Front? Back? Driver side? Passenger side?

Is the sound constant? Does it pulsate? Does it chirp once and then it's silent for a while? Does it increase with vehicle speed?

 

[lvwill]

Could be a dry u-joint on its way out.

 

[silverhawk184]

Thank you for the comments guys. I spent over an hour driving around town today, trying to catch this evasive creature on film.

After 10 minutes of 45+, I first heard it at a stoplight. I turned into the first neighborhood and it stopped before I was able to get it.

Then I drove a couple more miles and pulled into a parking lot while it was chirping, left it running, parking break set and walked around to hear where it was coming from. I had about 5 seconds to figure it out before my aftermarket electric radiator fan came on and bogged the engine down for a split second and it went away. I was able to tell it was coming from the front, passenger side.

Further down the road, it started again and I pulled into a gas station where it went away. It seems to only chirp while hot, and as soon as I park, it cools down and stops.

On my way back, I took a back road (30mph) and noticed that it was chirping if I floored the gas while the clutch was fully engaged. Given that it is a 4 banger with the A/C on, I doubt it was able to spin the clutch. It didn't rev, but the engine does get louder as the throttle opens.

Speaking of the clutch, I did replace it, the rear main seal, the slave cylinder, and the pilot bearing back in Oct 2015. Come to think of it, it was squeaking before then too. (I don't drive it often)

When I pulled into the driveway, it was squeaking and was able to get a recording.

https://photos.google.com/search/_tv_Videos/photo/AF1QipPFnK31VZGZOpF9xUaPRa2gkrit3a215XQjKGdp

It does not seem to be related to the rpms exactly, but chirps when it hits certain harmonics. Please let me know what you think!

 

[Kurt.king870s]

Kinda a long shot, but i've seen exhaust gaskets lose their seal and they would squeal because they would vibrate (in this case between the exhaust manifold and the head) but that was a turbo diesel, so it had alot of back pressure which caused the squeal to be Hella loud.......but if you have a manifold getting a bit loose, that could be your sound......and the manifold could flex a little when it gets hot and lose its seal. Just a thought

Nvm, I just realized that he said it keeps going when the engine is off. This is probably not your issue.

 

[Curious Hound]

Here's another long shot...

mechanical fan clutch?