I have a 2008 Subaru Legacy with about 57K miles on it.  Recently, I've noticed a slight grinding sound whenever I accelerate, particularly when the car reaches certain speeds. The sound appears to be coming from under the car near the front.  It is most noticeable when the car is around 25 to 30 mph but I can hear it slightly at some other speeds also.  There is no sound when slowing down or braking... and this happens when going straight.

 

Does this point to a problem with the transmission?

 

I had the transmission oil changed (and front/rear differential fluids) about 4 years ago when the car had 34K on it.

 

Should I get another transmission oil change or what else do you recommend?

 

Thanks

 

you never hear the noise at idle?

 

would the sound change if you lightly engage the brakes?

 

have the brakes ever been changed on the car?

 

could be the caliper(s) are dragging.

The brakes have been changed on this car.  I don't hear the same sound while braking or when the car is slowing down. The sound is only present while accelerating and as the car passes certain speeds... so I assume that it when the transmission is shifting.

 

On a side note, this car is VERY loud on a cold start. But when started later after a short drive (when the engine is warm), the start up is not very loud.   I've had several other cars (not Subaru) and never experienced the same level of noise at a cold start.

Have you checked the front differential fluid level?

 

Anyway you may need a mechanic to drive/check-out the car.

we can infer automatic - but in the future tell vehicle/year/engine/trans when diagnosing.

 

heat shield?  they get rusty, loose, and rattle at certain speeds sometimes?

 

can you describe the noise more?  like when it does it and variations or how consistent it is?

 

sounds like a front differential.

inner CV joints can make noise when accelerating too

 

if you think it's front diff related (transmission) - have the fluid drained and ask them to check for particles/material in the fluid.

or if you're really sure - just ask them to diagnose it so you don't pay for an unecessary fluid change.

Edited October 7, 201510 yr by grossgary