03 Grand Prix 3.1L Noise accelerating/braking
So I have been suffering with a popping noise when I speed up, brake and sometimes on bumps. I replaced both upper strut(dogbone) mounts and lower engine mount, as well as transmission mount in last 2 weeks. Still hearing noise. Tested mounts by tapping pedal with parking brake on and less movement now but same noise while driving. CV axles are fairly new (about 60,000 miles, 270,000 on car) . Strut/coil spring assembly replaced about 60k ago. Noise is not evident when bouncing car on either side. Mechanic at tire place listed above as cause plus front stablizer bar movement (I have new stabilizer bar link bushings to install later today). I usually hear about 3 pops on accelerating hard and 1 loud one on braking hard. Any suggestions on things I might be missing would be appreciated.
Hey thanks for the reply! No, I don't feel it in the steering. Drivers side wheel bearing is good, Passenger side I replaced about a month ago, had a loud droning noise like being on an airplane. Checked play on both sides and sure enough, put a Moog bearing in and corrected that situation. Today I added a new Pass side outer tie rod end, after wrapping that up I did an experiment:
Kept the wheels off and while still on jack stands conducted the same test I saw recommended by a motor mount mfr on RockAuto. I had my son rev the engine with the parking brake and brakes on.....no noise though a fair amount of movement at that new lower mount, I'd say the engine shifts at least 2 full inches. Put wheels back on and lowered car, rev engine again with brake set, could hear those pops. Sounds like coming from pass side but can't see what the issue is. On top it looks like those square rubber pieces on the brackets that bolt to the frame above radiator travel the full range possible, so much play, wondering if I should get Delco replacements for those??? Lower mount just put in is hydraulic, maybe should have went solid???
I do find it interesting that the noise is prevalent with the load of the car on the suspension as opposed to on jack stands. Just dropped at garage, front tires almost bald, guess we'll see what alignment does.....
Let me know your thoughts
Kept the wheels off and while still on jack stands conducted the same test I saw recommended by a motor mount mfr on RockAuto. I had my son rev the engine with the parking brake and brakes on.....no noise though a fair amount of movement at that new lower mount, I'd say the engine shifts at least 2 full inches. Put wheels back on and lowered car, rev engine again with brake set, could hear those pops. Sounds like coming from pass side but can't see what the issue is. On top it looks like those square rubber pieces on the brackets that bolt to the frame above radiator travel the full range possible, so much play, wondering if I should get Delco replacements for those??? Lower mount just put in is hydraulic, maybe should have went solid???
I do find it interesting that the noise is prevalent with the load of the car on the suspension as opposed to on jack stands. Just dropped at garage, front tires almost bald, guess we'll see what alignment does.....
Let me know your thoughts
Thread
Thread Starter
Forum
Replies
Last Post
DeathDealer
General GM Chat
10
Jul 17, 2012 04:50 PM








