Daniel here, Melbourne based new member! Have arrived with a high recommendation from a friend who is a member on here also. Here for the long haul!
In recent times, I have taken ownership of a 2010 2.0L Impreza, 4AET with full documented service history. At the moment, it has 115,000klms (70~k miles). The only slight issue I have now is mentioned below - which I am hoping to clarify and have rectified.
To very briefly explain it - at around 60-65kmh, with the foot on the gas. As soon as I let go of the gas and the car coast/decelerate, a noise not too dissimilar to a higher pitched sound "weeeeeeeeeeeeeeee" is heard. It is not obnoxiously loud, but is noticeable - a higher pitched noise - and as the car slows, the noise also winds down until around 10-15kmh, where it clears.
The noise is NOT present on acceleration - literally only with the foot off the gas/decelerating from the above speeds. Not heard at idle either.
As I mentioned above, the car has a full documented service history - the timing chain/tensioner was serviced by a Subi dealer at the 95,000klm mark, a year and a half ago. Transmission was also serviced in the last 10,000ks.
Being relatively mechanically minded (but not a pro by any standards) - it sounds like some sort of bearing noise, which I have read a little that it "may" be. Hence, I am asking this question of trying to eliminate the guesswork - if anyone does have any pointers or advice, I would greatly appreciate it.
Cheers - D
- AUSUBARU ELDER
- Posts: 5287
- Joined: Sat May 30, 2009 10:15 am
- Location: Australind closer to where they divided by zero
A video if you can of the noise in the area of the driver would be great. please don't do a Blair witch project and try to follow the noise, just have the phone set up in the general area of the noise and record the noise as it happens.
Since the noise occurs under deceleration, could it be a vacuum leak or similar (I know you said it sounds mechanical)? Or does it sound different? It's possible there is e.g. an EGR leak (if the car has one still, most modern vehicles don't need it anymore) or some other 'whistle' caused by some other induction control manifestation. As you said the timing chain/tension was done (relatively) recently, it's possible something didn't get tightened up or refitted properly and has worked its way loose.
One way to check whether it is vacuum or mechanical may be to slip the transmission temporarily into neutral whilst decelerating (coast) and see what happens. Also try shifting manually and see if the noise follows the revs or perhaps the gear. Try revving the engine and letting it settle back to idle too whilst coasting in neutral may help isolate e.g. transmission vs engine?
Ex- 2010 Forester Diesel