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General Forums => The Mess Hall => Topic started by: matmastin on March 19, 2010, 02:58:03 AM

Title: Whining/screeching noise with foot off the gas
Post by: matmastin on March 19, 2010, 02:58:03 AM

My 95 YJ makes a high-pitched screech/whining noise when I take my foot off the gas, after driving at highway speed for a while.  It does it any time my foot is off the gas pedal.  It sounds like my belt is slipping, but it is not.  It will usually go away momentarily when I stop at a red light.  It also does it between gears when my foot is off the gas and cluch is depressed - stops as soon as I touch gas. I have tried to get up there to open the hood to see what it is, but it has always stopped by the time I can get the hood open.  Anyone ever heard of this?

Title: Re: Whining/screeching noise with foot off the gas
Post by: sharpxmen on March 19, 2010, 07:54:01 AM

Quote from: matmastin on March 19, 2010, 02:58:03 AM

My 95 YJ makes a high-pitched screech/whining noise when I take my foot off the gas, after driving at highway speed for a while.  It does it any time my foot is off the gas pedal.  It sounds like my belt is slipping, but it is not.  It will usually go away momentarily when I stop at a red light.  It also does it between gears when my foot is off the gas and cluch is depressed - stops as soon as I touch gas. I have tried to get up there to open the hood to see what it is, but it has always stopped by the time I can get the hood open.  Anyone ever heard of this?

i would've say the same thing (the belt) although that is more when you accelerate not the other way around.

for a test take the tube off the throttle body (the one that comes from the air filter) and see if it still does it, i'm thinking might be something with the air box, air filter or velocity insert (air whistling thru somehow).

that's the best i can come up with.

Title: Re: Whining/screeching noise with foot off the gas
Post by: Jeffy on March 19, 2010, 07:38:30 PM

Water-pump bearing?

Title: Re: Whining/screeching noise with foot off the gas
Post by: sharpxmen on March 19, 2010, 07:50:34 PM

Quote from: Jeffy on March 19, 2010, 07:38:30 PM

Water-pump bearing?

but why only when decelerating?

i wonder if it's not some vac line that does that.

Title: Re: Whining/screeching noise with foot off the gas
Post by: Jeffy on March 19, 2010, 08:04:24 PM

Quote from: sharpxmen on March 19, 2010, 07:50:34 PM

but why only when decelerating?

i wonder if it's not some vac line that does that.

I don't think it's the belt since it's not consistent.  Although eh could try cranking the wheel to one side and force the pump to run at peak pressure which should cause the belt to squeal if it's too loose.

I don't think anything else would make a similar noise other then maybe a bearing, idle, water pump or alternator.

Brake chirp is different as well.  Intake would make a whistle or a sucking sound that I wouldn't think would be loud enough to sound like a belt.

Title: Re: Whining/screeching noise with foot off the gas
Post by: dwtaylorpdx on March 20, 2010, 02:25:12 PM

I've had a Transmission Input shaft Pilot Bearing do this before.....
The one in the back of the crank.

Dave

Title: Re: Whining/screeching noise with foot off the gas
Post by: ChuckC806 on March 21, 2010, 01:17:09 PM

I had this same problem.  It'd go away when under acceleration, but at the stop sign/light or just starting it up, it'd start squealing and I'd have to hit the gas a little.  I thought that I had the belt tightened up like it should be, but took it to my buddy's shop and he tightened it up some more and haven't heard a peep out of it since.  Even with the heater/ac on.