I have a 1998 2.4L Grand Am GT. There is a loud popping noise under the car when I turn and go forward or reverse. We have changed out the struts, A frame bushings, the ball joints, sway bar bushings, strut mounts, drive axles, bearings and so forth. Some guy said that it might be the sub-frame assembly where it meets the uni-body. Can I get some advice? Thanks.

Welcome to the forum. Have you checked your CV boots / grease?

Aside from that, he might be right about the sub-frame assembly. Have you checked all the bolts for snugness?

Welcome to the forum. Have you checked your CV boots / grease?

Aside from that, he might be right about the sub-frame assembly. Have you checked all the bolts for snugness?

They are all new. All the bolts are tight and have been retightened just to make sure.

any loose plastic in the fenderwells, or around the wheel, or where the pitman arms would touch under the car. Just a thought.

any loose plastic in the fenderwells, or around the wheel, or where the pitman arms would touch under the car. Just a thought.

Yes sir. We checked all clearances and there isn't anything rubbing. We even removed both A arms and installed new bushings and torqued the bolts down. We are really baffled.

Is it pop or a crunch sound? And does it happen either way you turn? I'm thinking several things, and a couple are ugly. First, worn cv joints will make a popping sound when they first start to fail, then turn into a crunching sound when they get really bad. Second, defective ball joints as they will pop when you turn the wheel. Third, sticking bearing plate in the strut mounts, I had this happen with new bearings, one turned out to be defective. Fourth, and the really ugly one, a weak spot in the unibody allowing the sub frame to walk around a bit with a big chunk of floor attached to it.

Is it pop or a crunch sound? And does it happen either way you turn? I'm thinking several things, and a couple are ugly. First, worn cv joints will make a popping sound when they first start to fail, then turn into a crunching sound when they get really bad. Second, defective ball joints as they will pop when you turn the wheel. Third, sticking bearing plate in the strut mounts, I had this happen with new bearings, one turned out to be defective. Fourth, and the really ugly one, a weak spot in the unibody allowing the sub frame to walk around a bit with a big chunk of floor attached to it.

Thank you for responding. The cv joints are brand new, no miles, the ball joints are the same, brand new. Also the bearing plates and the struts, not to mention the A arm bushings and the stabilizer bushings and link pins. The entire front end has been gone through basically. It must be the sub-frame assembly. Thank you again.

RobertPatt, this noise is when you turn either way. When you accelerate does it get worse(louder) and feel like it doesnt want to move? I had an 93' GA and it had the problem i described, it was the transmission. the plantery gears were broken. Hopfully this isnt your case, since you've spent quiet a deal of time and money already on the new parts. Good Luck

Thank you for your info. We will check that again. It seems to only happen when I turn about 60% of the way. Forward or reverse, only on take off, one pop. Loud pop.