another mysterious, 30 year old truck noise thread LOL

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Vbb199

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Truck has recently started making a noise... it can only be heard with engine under load (driving), not sitting in park revving the motor, a "whirling" and "whining" can be audibly heard from the engine bay/tire area, driver side.

The noise im hearing is engine noise im almost sure. But idk where. Without fail, everytime i slow down to a stop sign, or light, you can hear the "whirling" slow down with the truck...... Just out of randomness, today on the way home, i turned the engine off with it in neutral going 55mph so i could hear the drivetrain/tires/etc without a noisey exhuast.... as soon as it was off, and trans in neutral, i couldnt hear a sound... As i slowed down approaching my driveway... no audible sound was made from the truck... theres an engine related noise that is only audible when the engine is on and under load. Wtf?


Its not the rear end, at least i think. Its not excessively hot or anything.

And as i said, it only is heard apparently when the engine is on and im rolling at the same time.
What gives?

I know this like a total game of shot in the dark, im only really posting to see if someone has heard of such noises at these very specific conditions before.

I can try to get a video, but the truck is pretty loud... i can almost "feel it" in the steering wheel when slowing down (engine on)

Im thinking PS pump since its old asf, recently developed a leak, and i let it get a little low....
I filled it back up, same ****.

Thoughts?

TIA
 

Jwernatl

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motor mount? - something under load engine twisting? Maybe trans mount or cracked bell housing?
 

bucket

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I dunno, your exhaust must not be too loud if you can here a faint noise under the hood :rofl:

When I got my '92 Camaro years ago, there's was a noise similar to what you describe. It sounded like a PS pump that was low on fluid, but only made the noise while driving. It turned out to be a pump noise in the 700r4. I had my favorite trans shop go through it and it has been fine since.
 

bucket

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Hopefully that's not your problem though.
 

Vbb199

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Hopefully that's not your problem though.


You're damn right, i hope not.
That 700r4 is still wet behind the ears!!!!!
 

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My vote is the ps pump too. Can you pull the belt off and go old school on a back road to see if the noise goes away?
 

Vbb199

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My vote is the ps pump too. Can you pull the belt off and go old school on a back road to see if the noise goes away?


Its serpentine, i would just have to get a belt that bypasses the pump.
 

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That's the 1st thing I'd check too, P/S pump.
I'd check all the pulley's as well, ,tensioner, water pump bearing. You can isolate the noise with a stethoscope (homemade).
 

Vbb199

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That's the 1st thing I'd check too, P/S pump.
I'd check all the pulley's as well, ,tensioner, water pump bearing. You can isolate the noise with a stethoscope (homemade).


I was thinking the same myself.
Im gonna pull my belt this evening and check pullies.

It doesnt make since though, why does it only do it under engine load? Seems like any of those pullies would make noise sitting in park
 

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Belt tensioner bearing?

Just a shot in the dark
You must be registered for see images attach
 

Vbb199

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Belt tensioner bearing?

Just a shot in the dark
You must be registered for see images attach



I will say, the tensioner itself started making a clicking sound last year when it started to get cold, so this is at least a good suggestion. Ive never fixed the clicking tensioner considering theyre like, minimum 50$
 

Vbb199

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Hear me out:

This noise did start after i did all the front end components and such, truck is pretty bad out of alignment, i deduced somehow in my own mind, what if the alignment is wack and putting excess stress on the steering pump?

I dont have to fight it to keep it on the road or anything, but i can see i have a passenger side toe in problem, and the tires dont perfectly go in a straight line... i havent felt like really fixing it considering today is alignment day, last weekend was front end day, and i got new tires like, tuesday or wednesday.

I intially assumed, maybe the tires are making the noise now.. its possible.

I will say on a side note, at certain speeds, and a specific harmonic frequency (engine rpm to vehicle speed), it can be heard the most. A very slight, (LIGHT) throttle tap makes the noise go away.

It happens in any gear, but only at vehicle speed or slowing down, im to assume "for now" its not the transmission, altho i did read story after stort last night about failed converter torington bearings, or clogged up fluid pumps......

Automatic transmissions dont scare me, but i DONT want to pull that trans out since it easily has less than 5,000 miles on it.
I dont make enough power to tear it up, it was built for 600hp.


Fluid is nice bright red (havent changed it since install of trans) but i did notice clutch dust on the dipstick, so possible clogged filter could be an explanation.
 
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