High pitched engine noise

[jupoa]

My '97 460 used to only make a high pitched noise under extreme load with WOT but now it is making it almost constantly. Just the volume varies with load, not the pitch. It sounds electronically generated because of the constant high pitch. I would think a bearing failing or wind noise would vary in pitch. Of course, it sounds like its coming from anywhere and everywhere.

So far, it doesn't seem to affect performance in any way. It is just annoying and worrisome.

Thanks for any response.

[Lt46]

Well, I'll give you something to look at. My 97 460 became very noisey one day and it turned out to be the EGR valve. Don't ask me what happened, cuz I don't know but replacing it quieted the thing down. Had to have a buddy drive while I had my doghouse slid back and me laying on top of the engine to narrow down exactly what was making noise. Good luck.

[1skatingrin]

I had a sound that varied with rpm. turned out to be the radio.

[jupoa]

LT46

Where did you find an EGR valve? I've looked on Ebay and several parts places and cannot find anything like mine. It has a position sensor built onto the top of the vacuum part of the housing. Looks expensive and I already broke it taking it off.

[Lt46]

Got mine from Ford. Wish I saved the box w/ part # but didn't. Sorry.

[RVhauler]

Check the fan clutch

[ga traveler]

We had several power steering pump bearing failures in this time period. I think this could be a PS pump bearing. You might try lubing the power steering pump bearing.

[Bushman512003]

Years ago had a bad belt make a sound that was hard to track down a new belt fixed it up.Just a idea.Good luck

[jupoa]

Found the correct EGR valve at NAPA and installed it. Thought it worked at first but the noise came back worse than ever after about an hour of driving.

Replacing the belts (2 polygrove flat belts) and checking all the pulley bearings while the belts was off the next step planned. I thought it would be very difficult because the only apparent access to the front of the engine is from the bottom and I couldn't see any way to get the fan shroud out of the way. Turns out, if I cut the front wheels to the left, I there's just barely enough room to loosen the alternator from the side and remove the front belt. When I cut the wheels to the right, there is just barely enough room to get a long wrench onto the tensioning pulley from the side. By hooking a cargo strap onto the other end of the wrench and the frame below, I torqued the pulley enough to remove the rear belt. Getting them over the fan inside the shroud just involved slipping them over one blade at a time as I turned the fan. Replacing the belts just pretty much involved reversing the above steps.

None of the pulley bearings seemed to feel bad so I just cleaned the pulley faces with solvent before replacing the belts. It's quiet at idle but it's not unusual for it to be quiet when it's cold. Will test drive in a couple weeks.

Tip: AutoRock sent me the wrong size belts even though I chose the belts from their menu for the 1997 F53 460.

[RoyM]

What rv hauler said. The fan clutch could be seized so the fan turns all the time.

[jupoa]

RVhauler and RoyM,

Thanks for your replies.

The fan spins freely with the pulleys off. With the engine off and the pulleys back on it won't spin freely but I can turn it without much effort. Is it supposed to spin freely with the pulleys on or is some amount of drag normal?

[TNMike]

Do you have the numbers of the correct belts?

[jupoa]

TNMike,

The belts that came off were Motocraft F4UA8620 AU1A and F2TD8620 BB. After finding that the RockAuto belts wouldn't fit, I just took the original belts to a local auto parts store to make sure the one's they sold me would be the same size. One is a 6PK1510 595K6 and the other is in a position where the number is not visible just now.

[Bushman512003]

the fan pully should have some resistance with belts on .