I've got a 2008 GT. I bought it with 32k on it and it is now at about 63k. There is a strange whine from the engine. Not related to transmission because it does it in neutral (manual transmission). Sounds like a mechanical whine that increases with rpms...

Regular oil changes since I've had the car (about a year) and no real abuse (at least since I've had it). No one has said anything about shavings or anything in oil at changes and I am not burning oil. Regular temperatures and warm ups and acceleration... Just this weird noise. Almost like a supercharger or one of those old fire engine sirens.

Replaced alternator when I bought it. Could that be going bad (assuming I got a bad one)? Voltmeter (which is near useless) shows "... normal." Water pump or A/C pump? Engine temps are "... normal" and A/C kept me reasonably cool during the Georgia Summer.

The whine is loud enough to discern at idle when you are outside of the car at the front. You also hear it over the exhaust note in the cockpit. But again, the car otherwise runs out fine and I am noticing no irregularity.

New member and any help appreciated from someone who may experienced something similar. I don't have one of those auto-stethoscopes so I can't really pinpoint it other than what I've set out.

Thanks in advance for any input.

JKC

 

Another way to describe sound is like when you run a tire on rollers and grind it to a stop. If that makes sense. Or, maybe even a wearing belt? I'll take a look at those when I head out to lunch.

JKC

 

if the sound is from the front of the engine it is likely a/c, alt, or power steering pump. It might also be the belt tensioner pulley bearing. Water pump sometimes wine, but not a lot. Belts normally just break.

1. If the noise get louder as you turn the steering wheel add power steering fluid.
2. The alt is on the top center of the engine so if noise is from it you'll likely be able to tell it.
3. It could be ac and if the noise is louder under the front of the car than from the top that might be it.

Take off the belt a spin a few things by hand. If you feel a drag or wine you likely found it.

 

Make sure you listen with AC on and off. I heard a noise in a drive thru one day while in neutral and turned off the AC, it went away.

 

Thanks, guys. I will give that a listen.

It does not seem like power steering, because those usually kinda groan, but I'll give that a try. Agree on water pump. Had one of those fail and it just rattled like a diesel until it failed.

Will check with A/C on and off. I run my compressor all the time to control humidity and haven't thought of that. I'll also give it a closer listen with the hood up.

JKC

 

Make sure you have your battery fully charged and the car is cold.

Remove the drive belt and start the car. Is the sound still there? Then it's engine related. If it's gone, it's an accessory problem.

 

Listen to your idler pulleys on the belt drive up front, could be a bearing going out.

 

I would check the idler pulleys. When I test drove mine before I bought it it had a whine, it was an idler pulley.

 

When I left work last night I opened the hood and listened and it seems to be coming from the front, where the accessories are. I did not hear anything from the passenger side.

Pulling the belt is a great idea but I don't have the time to do that anymore.

Forgive my ignorance, I have a working understanding of engines and systems, but about a B - level. Not quite a gear head, but I get the concepts and stuff. Idler Pulley seems to be a tensioner or reducing/increasing pulley in the belt system... Correct?

I have a mechanic I trust, I think what I am going to do is pop by there and point out some of our discussion to see what they think.

I appreciate the input. This is my son's car (on loan to me) and I've had similar, positive experiences and interactions on the forum for my own car. It helps a lot.

I will report back when I find out what is going on so someone else might benefit.

Take it easy,

JKC

 

Idler pulleys are the ones that are free spinning, the tensioner has an idler pulley, the other idler pulleys are bolted to the engine cover. besides the idler pulleys, the only other pulleys are on the accessories, the power steering pump is low on the drivers side, the water pump is in the center, the crank pulley is at the center bottom, the alternator is at the center top, the air conditioning compressor is on the passengers side for a 2008 mustang GT...



so #'s 3, 5, 7, 9 are the 4 idler's