Screeching sound in fan area

[Steve D.]

63, 327

When accelerator is bumped from idle, I get a screeching noise that sounds like a fan blade rubbing against the shroud. The noise is not sustained, and stops after initial acceleration. I pretty sure it's not the fan because the shroud clearance is more than an inch, and by observation there is no wobble. The fan is secure and I have checked the belts and the pullies and all seems ok. Two other possibilities come to mind: the fan clutch and the water pump. Both are new, but with my recent experience with a "new" coil, I'm not ruling anything out. Any suggestions about how to pin down the noise source short of trial and error replacement of fan clutch and/or water pump?

Steve

[Edward J.]

Re: Screeching sound in fan area

Steve, is there loose fan belt? When not tight enough they tend to squeel on start-up and on acceleration.

[Timothy B.]

Re: Screeching sound in fan area

Steve,

Take the water pump belt off and run the engine. If the squeel stops you know it's narrowed down to W/P, belt, or fan clutch. At that point you can remove the fan and bolt the pulley snug and run the engine again to further narrow it down.

Look at the pulleys to see if they are warped and wobble when the engine runs, also, you can use a bar of soap gently on the belt to see if it quiets?? My 63 makes a low RPM noise but I know it's the W/P.

[Steve D.]

Re: Screeching sound in fan area

Thanks. I hadn't focused on the fact that the fan, pump and alternator aren't required for short runs. I'll check this afternoon. This shakedown is touching more bases than I expected.

Steve

[Steven B.]

Re: Screeching sound in fan area

Steve, if after narrowing it down---all very good suggestions given---and you think it may be the belt take a bar of soap and rub on the belt where it runs in the pulley to see if that stops the squeeling of the tightened belt.

Steve

[Edward J.]

Re: Screeching sound in fan area

Steve, most of the time belt squeel on start-up is generally a loose alternator belt, if the belt squeels say when you turn the wheel, its a p/sterring belt, If you have a/cond. and you turn the compressor on you get a squeel the compressor belt needs adjustment.

One small note, the reproduction belts seem to have a problem if you over tighten them. (There short lived)

[Bob R.]

Re: Screeching sound in fan area

You may also want to check your motor mount. A broken motor mount will allow the engine to raise up and strike the fan shroud.

[Clark K.]

Re: Screeching sound in fan area

Steve, if after narrowing it down---all very good suggestions given---and you think it may be the belt take a bar of soap and rub on the belt where it runs in the pulley to see if that stops the squeeling of the tightened belt.

Steve

Safety Note: do not do this with the engine running!
-Clark

[Paul J.]

Re: Screeching sound in fan area

Steve,

The soap trick is the VERY FIRST thing that you try. You put it on one belt at a time and rev the engine, until you find the belt making the noise. If you don't find that it's a belt then move on to the next steps. If you use a bar of soap, you need to have the engine running, but if you use liquid soap you can can do it with the engine off. Remember, you only need the smallest amount of soap.

Paul