Whining noise linked to RPM, what is this?
09-05-2023, 12:07 AM
#1
Whining noise linked to RPM, what is this?
My 04 Turbo has had an annoying whining sound for a while now but it has recently worsened to the point where driving through the city with the noise reflecting off walls and buildings you hear more whine than exhaust note.
The noise is linked directly to engine RPM's and can be heard when revving in neutral (listen to video below) but is most prevalent in lower gears at higher RPM's when under load. If you turn off PSM and the car starts in 1st and revs high before going to 2nd this is where it sounds worst of all.
At first I thought perhaps it was the gearbox or transfer case, but if that were the case it shouldn't happen revving in neutral. I have let the car coast down a hill in neutral too and I didn't hear anything so obviously not a diff.
My thoughts are it must be an accessory or idler pulley on the front of the engine. It does actually a sound a bit like a turbo 'death whine' but I haven't seen anything about that happening on these cars, not to say it's impossible but I would have thought a turbo failure would be accompanied by smoke and CEL, etc which my car doesn't have.
Any thoughts on what this could be are appreciated as I really want to hear that beautiful V8 exhaust note while driving, not this horrible high pitched whine!
The noise is linked directly to engine RPM's and can be heard when revving in neutral (listen to video below) but is most prevalent in lower gears at higher RPM's when under load. If you turn off PSM and the car starts in 1st and revs high before going to 2nd this is where it sounds worst of all.
At first I thought perhaps it was the gearbox or transfer case, but if that were the case it shouldn't happen revving in neutral. I have let the car coast down a hill in neutral too and I didn't hear anything so obviously not a diff.
My thoughts are it must be an accessory or idler pulley on the front of the engine. It does actually a sound a bit like a turbo 'death whine' but I haven't seen anything about that happening on these cars, not to say it's impossible but I would have thought a turbo failure would be accompanied by smoke and CEL, etc which my car doesn't have.
Any thoughts on what this could be are appreciated as I really want to hear that beautiful V8 exhaust note while driving, not this horrible high pitched whine!
Last edited by tassieporsche; 09-05-2023 at 12:37 AM.
09-05-2023, 09:19 AM
#2
RL Community Team
Rennlist Member
Rennlist Member
You're correct in thstbitsnone of your pulleys. This happened to me on my pickup after I changed a water pump. A few weeks later the tensioner pulley completely disintegrated on my way somewhere and then threw the serpentine belt. Luckily I coaster into the parking lot of an Advance auto parts and replaced it on the side of the road and was on my way again in 30 minutes.
Pull the belt and see which pulley(s) need replacing.
Pull the belt and see which pulley(s) need replacing.
The following users liked this post:
tassieporsche (09-08-2023)
09-08-2023, 09:22 PM
#3
Thanks for the reply.
I'll pull the serpentine belt off when I have the chance and see what I can find. Looks pretty hard to pull the belt off completely so maybe I'll just loosen the tensioner then spin each pulley individually until I find the suspect one.
I suspect that the power steering pump may also be the cause here, although the level is good in the reservoir and there are no evident leaks. Maybe an old seal that is letting air into the system but no fluid is getting out?
Noise does not change when I turn the wheels though.
On top of this my new valve body that I replaced last year is having shifting issues
It's a never ending journey with these old pigs haha
I'll pull the serpentine belt off when I have the chance and see what I can find. Looks pretty hard to pull the belt off completely so maybe I'll just loosen the tensioner then spin each pulley individually until I find the suspect one.
I suspect that the power steering pump may also be the cause here, although the level is good in the reservoir and there are no evident leaks. Maybe an old seal that is letting air into the system but no fluid is getting out?
Noise does not change when I turn the wheels though.
On top of this my new valve body that I replaced last year is having shifting issues
It's a never ending journey with these old pigs haha
