unknown problem with 2004 Outback

[fraver]

I have a 2004 Subaru Outback with 120,000 or so miles on it with very few problems. For some time now I  have heard a sort of thumping like a tire sound on the highway. I've checked the tires several times and they are okay.Yesterday, when we returned home I noticed in our driveway, which was a little wet and soft, so the tracks were real clear, that what looked like for every tire rotation the track was rough like the wheels were dragging. I don't know how to explain it any better. If it helps, I had a front right cv joint replaced about a year ago which is about when the noise started. Any help would be very much appreciated.

[idosubaru]

each of these questions is specifically geared towards telling us something specific about a bearing, front diff, axle, tire, etc:

 

1.  is it always there at 1mph and 100mph?

2.  engine or speed related (sounds like it's speed related - tires)

3.  any smells - like something is hot?

4.  is there much heat

5.  differential fluid ever been changed?

6.  how OLD are the tires?  (not how many miles or tread depth)

7.  front or back and left or rear?

8.  does the noise change when turning at all?

9.  any vibrations or feel at all - you said you just "hear" it?

10. automatic or manual?

11.  if any automatic does the TRANSMISSION light blink 16 times at start up?
12. any check engine lights?

13.  if an automatic (and not VDC) - does it go away if you insert the FWD fuse?

 

my first guess on limited info is a bad tire.  rotating them and seeing if the noise "moves" can isolate it.

wheel bearing, torque bind...

 

aftermarket CV axles are really, really, bad.  i can't exaggerate how terrible they are.  but as you can tell you haven't given us much specific information, more details will help.

Edited March 16, 2014 by grossgary

[fraver]

 Thanks for your help. To answer your questions:  1. any speed, louder and faster with speed. 3.  no smells. 4.  no heat.  5.  I think not.  6. tires are good. 7. very hard to pinpoint.  8. same when turning. 9.  don't notice vibrations.  10.  automatic. 11.  don't really understand the question.  12.  no check engine lights   13.  don't understand.   What does aftermarket mean?  My personal  opinion is it's the cv joint but I'm no expert. Thanks.

[heartless]

11.  if any automatic does the TRANSMISSION light blink 16 times at start up?

 

There is a separate dash light for the transmission - something along the lines of "AT Temp" - does that light blink when you start the car?

Does it come on at all when starting the car? Normal operation it should come on steady for a few seconds, then go out. If it blinks there is a problem and a stored code in the TCU (transmission control unit).

 

 

 13.  if an automatic (and not VDC) - does it go away if you insert the FWD fuse?

 

There is a fuse holder - typically located under hood on the passenger side strut tower, towards the firewall - when a fuse is inserted, it forces the car into FWD mode only. Try putting a fuse in there - size doesnt really matter, completeing the circuit does - and driving the car - Is there any change in the behavior?

 

Aftermarket is any product that is not an OEM (original equipment manufacturer) product specific to the brand of vehicle. Manufacturers have very specific parts suppliers. Most parts store axles are "aftermarket", not always of the best quality, and they are frequently the cause of strange issues on Subarus.