Subaru Outbak 2.5 Cold Weather Squeal

subaru
outback

#1

Need some help determining the cause of a strange high-pitched squealing noise coming from the engine compartment of my 2008 Subaru Outback 2.5l automatic. The squeal happens only when the temperature is cold (below 32 degrees) AND I hit a bump. It happens more often the colder it is outside. The noise is definitely coming from the front of the car and seems like the passenger side but I can’t be sure. It happens with the blower fan/AC both on and off so I don’t think it is caused by that. It happens when the car is cold or driven for a while and warmed up. It occurs at both high & low speeds. I checked all my fluids under the hood and everything is filled as it should be. There are no lights (check engine or ABS) on. Does anyone have any ideas? Recommend any troubleshooting that I can try? I have not taken it to a mechanic yet as they might have a hard time reproducing the noise since it has to be below freezing and hit a decent bump. I attach a video that I took while driving last week on a 16 degree day and heard the squeal when I hit a bump. I had been driving for about 30 min when it occurred. I have more videos of the noise if needed.


#2

It seems from your description like it is some accessory or belt problem. Is this a transverse mounted engine? With all the pulleys on the passenger side? That would explain why you hear it towards the passenger side. It only happens when you go over a bump? That’s unusual but not unheard of, could be related to engine mounts having some slack in them, affects the pulley routing slightly when going over a bump.

Do you know whether the sound is related to the engine rpms vs the wheel speed? Can you get the same sound to occur with the engine in neutral, coasting? If so, that would be a clue the problem is one of the front drive axels rather than a belt.


#3

I agree. The only squealing I have heard from the engine compartment in cold weather has been from a drive belt; and an occasional mouse or squirrel.


#4

Thanks for the replies. No, it is not a transverse mounted engine. The sound does not seem to be related to engine RPM and/or wheel speed. Seems to happen at various RPMs & wheel speeds. I’ll try to see if I can produce the sound with the trans in neutral. It is quite possible it is the drive belt. It has the original belt(s) on it…85k miles. I think I’ll go ahead and replace the belt(s) and see what happens to the sound.


#5

Very interesting. My guess is that you might have a bad motor mount. When you hit the bump the engine gets thrown off kilter causing the pulleys to not all be perfectly aligned.

Did you recently have anything replaced like an alternator or something? Could be loose and throws itself out of alignment for a second. The sound is the belt realigning itself I think.


#6

My guess is that you have a component bearing binding, perhaps in the power steering pump, the AC compressor, or the alternator, and when it binds it either causes the belt to momentarily slip or makes noise itself. When you go over a bump, that lateral pulse might be enough to momentarily throw the failing component’s shaft to where the bearing binds.

You might be able to find it by removing the serpentine belt and/or drive belt(s) and checking each crank-driven component for slop. Each should spin true and none should have play either laterally or axially.


#7

+1 there mountainbike


#8

Original belts at 85k would definitely make them a prime candidate for squeal. Even if they look “good” and have no cracking, they can glaze enough to slip in cold weather. That doesn’t mean they are due to break, it does mean they can start to get on your nerves. It’s a good dea to have them changed regardless and have the pullies checked while doing it. At this time, I would suspect nothing more until proven otherwise during inspection.


#9

Did you get this figured out? I have the exact same problem and exactly same car and year, with higher mileage on it. I would love to see am answer to this issue. I know this thread is very old, but any updates?


#10

Sounds like an ordinary suspension rubber bushing squeak. I have never seen a belt squeak when hitting a bump.


#11

Whatever it is , it’s a pretty common thing to hear squeals and squeaks and bird chirping sounds from car’s, esp in colder weather. I walk about 2 blocks along a 25 mph street on the way to work, and this morning I noticed about one in every four cars driving by was making some kind of squeak or bird chirping sound. It was quite a cacophony.


#12

kulawrence - No, I haven’t figured this noise out yet but I sure would like to! I still get the noise when I hit a significant road bump when the outside temp is below 32 degrees. I’ve changed the serpentine belt and that made no difference. I’ve also replaced the front struts and that made no difference (was time to replace them due to mileage - I didn’t really think the noise was coming from them). My latest thinking is that it is some sort of pneumatic/hydraulic sound rather than a suspension noise. The sound seems to be coming from the right side of the vehicle from somewhere around the engine/transmission. I suspect it’s coming from the transmission. The other day it made the noise and I quickly shifted the transmission into neutral while the noise was occurring. It seemed to make the noise last longer (perhaps 5-6 seconds) and then it went away on it’s own as it always does. Keep me updated if you figure it out. I have not bothered to take it to a mechanic as it doesn’t seem to be affecting anything other than my ears.