1998 Grand Am, 2.4L - Differential? Transaxle?

FEINNISH

MEMBER
1998 PONTIAC GRAND AM

Car is a 1998 Grand AM SE, 150k miles, 2.4L Twin Cam engine. I have had various things replaced in the engine over the last two years. The car has been running fine for 6-8 months. However, 3 days ago, the car suddenly started making a loud 'groaning' noise during my freeway commute. No changes in performance, just a noise. It made me think I was dragging a cardboard box or something. When I got home I checked under the hood and the noise seemed to be coming from everywhere, but nothing in particular. - Upon further inspection I noticed that when I put the car in gear, reverse etc, the noise went away. But, when putting it back in park, the noise comes back. Also, when in gear the noise is gone, but as I accelerate while driving, the noise returns. - Took the car to my mechanic and he thought it might be a motor mount, or transmission mount. However, he called me yesterday and said he'd ruled that out, all mounts seem fine. He now thinks it might be a 'differential'? Or perhaps something with the transaxle? Because when he put the car on the lift, he can't get the car to make the noise, confirming it only occurs when physically driving the vehicle. - He says that assures him it's not the transmission, but one of these other issues. - Is there a differential in a front wheel drive? Can he be on the right track? Is this an expensive fix? He says it wouldn't be worth fixing, in consideration of the cars value. - Can you shed some light for me? Thanking you, in advance. :

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

If it makes a growling sound when you get up to 35mph or so you have a wheel bearing problem. You seem to be saying the car makes noise sitting still tho? If so check the power steering pump, the rack and pinion part bolts to the car against the firewall, and you may be hearing tranfered noise! If you rule that out the tranny pump is the only other thing that could make noise while not moving!