96 Legacy Outback 5M 2.2 problems

[CardinaA]

Hey,

My 96 Legacy Outback 5M 2.2 has recently developed two problems:

 

(1): There is a distinct "whirr" coming from the area of what I believe is the air conditioning compressor (or whatever contraption is located towards the driver's side, next to the alternator, running on a belt) that I hear during all engine speeds and driving conditions. I live in the north, so it's been difficult to test the A/C but the defog function seems to work fine. Are the compressors prone to failure? Could it be an alternator bearing (I swear the noise is coming from near the pulley attachment of the compressor, though)Any thoughts?

 

(2) When I'm driving above 45 and take my foot off the accelerator, I hear a vibration underneath the car that sounds like it's coming from the exhaust system. Then, if I abruptly depress the accelerator, I feel a clunk in the drivetrain and the vibration goes away. At even slow speeds, I can let off the gas (not hearing any vibration) and then punch the accelerator and feel "slack" in the drivetrain (that is accompained by a clunk). Any thoughts on this one?

[Lesbaru]

I have a 96 Legacy 2.2 5 spd.

 

1. I haven't had this problem (yet)... My air conditioner system burbles like a fishtank, but no whirring yet.

 

2. I have a bad baffle (dunno what that is, I'm just trusting the mechanic) that gives me a similar set of noises. The baffle is somewhere in the exhaust system, and I will get it fixed when I have more money.

 

Dunno if thats any help at all, but it's what I've got!

[wrxsubaru]

For the noise is probley a exhust heat shield. For the clunk it could be a broken trannie/engine mount.

[Setright]

I had a clunking noise, which would be loudest when I braked hard and suddenly. Replacing the transmission mount solved it. Worth a try, since these things do become softer with time and it's relatively easy/quick to replace.

 

Certainly, you also want to check the heat shields, just cut them off if they are making trouble.

[harborseal55]

For the "whirring" sound, you can use a mechanical stethescope (I got a great little one from Sears ~15 years ago I think for around $20 that you can REALLY identify noises through) or, less precise but still potentially adequate, use a piece of tubing (heater hose or similar-size stiff hose), or even a metal rod. Position one end to your ear and touch the other end on the different areas that have bearings, like your A/C compressor, alternator, water pump, and anything else that is run by your belts like idler pully/tensioner (I've replaced those idler bearings on a Toyota every 100K or so but don't remember if Subs have them). You should hear the whirring noise VERY clearly when you find the right area if it's one of these bearings going bad. Be careful not to catch your listening tool in any moving parts!

 

Note for checking your A/C compressor, test that two ways: one way with the compressor "off" (you can make sure that it's off by turning off the A/C and positioning the vent selection switch to anything other than the windshield defrost position, as the compressor will periodically engage in the defrost position even if the AC is turned off), and check it again with the compressor "on" by turning on the AC.

 

Regarding the drivetrain clunk and rattle noises, I'd jack up the car and (when the drivetrain has cooled down) climb underneath and simply bang around on things with your hand to see if something simply seems to be loose or noisy.

 

If nothing seems obviously loose, there are some boothstrap ways to check for gross U-Joint or rear axel problems that work at least on the older cars and I would think would still work with AWD. Jack up the rear end of the car (both tires off the ground) and try to easily rotate them back and forth with your hands. Now, the goal isn't to try to actually "turn" the wheels, but to see if you feel "play" or clunking when you move back and forth. If the rear end has play or if a U-joint is really bad, you might notice play or a clunk right there and see if you can tell whether the noise is coming from the rear end, driveshaft (probably the most likely culprit), or transmission (the least likely culprit). In my experience with bad U-joints on other cars (not Subs), a U-Joint (or driveshaft CV joint) can be going bad and, although not loose by hand, can make clunking sounds in addition to "clicking sounds" that one can hear from under the car while driving. Have someone drive the car SLOWLY down a QUIET alley (alleys are great because some of the sounds you're listening for get bounced back off nearby buildings and so are easier to hear) while you open the passenger door and try to listen for "clicking" from under the car. U-joint clicking sounds are not nearly as loud or noticable as those from front axels when the CV joints are going bad, but any clicking from them means they need to be replaced.

 

Good suggestions above to check the engine and transmission mounts too - they can break in half and allow the drivetrain to move around loosely.

 

Oops - perhaps it's the old Sierra Nevada bottle or tire jack still rolling around in the trunk after all these months.....

 

Good luck and hope it's something simple.

[SUBARU3]

If you have the Calsonic compressor, it might be the bearing in the clutch. I had to replace mine. (95 Impreza) The clutch can be removed from the compressor and replaced fairly easy. I'm told the compresors will outlast 2 clutches!

 

I would first look at the idler pulley bearing though. They fail too and get noisy.

 

Todd