Noises

[jtre]

Finally with my truck back on the road and holding coolant/oil, i want to see if I can address a couple noises.

The first is a very high pitched tweeting (sort of sounds like a very annoying bird) that occurs when I hit a bump (of course I took it out to try it tonight, but it is quiet...maybe the rain tonight affected it)..thinking a bad ball joint or bushing....Should I use some silicone WD 40 on one part at a time (when the noise comes back) to determine which part is affected?

Second issue: since I have owned my truck, I have heard a whine on acceleration/deceleration that sounds sort of like a turbo: it increases pitch as I accelerate, and decreases pitch as i decelerate. I have heard it is possibly a pinion bearing in the front or rear end? (doing a diff/T-case service soon, hopefully that will get rid of the noise or at least extend the life of them). I also hear a low pitched growl when backing out of my driveway or slowly pulling into a parking spot) Anything else to suspect with that type of symptom?

 

[J_C]

I could be way off but my two guesses are the high pitched sound is an HVAC blower bearing wearing out, and the turbo sound is a steering pump low on fluid or with air in the system. Low pitched growl, an exhaust leak.

I expect that I'm wrong about one if not all but a high pitched sound tends to come from high frequency of oscillation, something moving fast not a ball joint or bushing. A whine that varies with RPM tends to be an internal engine part or something belt driven. Getting under the hood while a helper revs the engine might help. The growl, since it happens at low speed, maybe in park or maybe not, someone on the ground closer to potential noise sources.

 

[jtre]

the tweeting sound is independent of the HVAC. possible on the pump, but i have full fluid and no leaks that I know of, so I am not sure about how air would get in there. Is the silicone WD40 test valid for bushings? That would be a fairly easy way to eliminate a possibility

 

[J_C]

Anything you spray into bushings will quiet them, even a soapy solution (while it's still wet), so long as you spray enough to get it in where the noise (might) be.

Edit: I mean rubber bushings. Metal bushings aka bearings like you'd find in a motor should get light oil.