1997 Pontiac Grand Prix

JLHOLDEN

MEMBER
1997 PONTIAC GRAND PRIX
6 CYL
FWD
AUTOMATIC
188,000 MILES

Car is making a deep grinding sound like rims are rubbing on something, but I have run it off the ground, and there is nothing visibly rubbing. You can hear it really good inside the car, but not so good outside, or underneath. Weird thing is that when it does it going down the road, it lightly wiggles the car like a warped rotor? Trans shifts good, and has had a fluid change recently, but the original owner had never changed it. We bought the car with about 180,000 on it. Free revving the engine doesn't change anything, and shifting to neutral doesn't change the frequency or tone.

Items that have been replaced up front: brake rotors, brake pads, both hub bearings, both outer tie rod ends.

Any help or suggestions would be greatly appreciated.

2 Replies

DLOBI

MEMBER
125 POSTS

When you have it up off the ground the suspension is hanging down, not compressed with the cars weight on it so that could make clearence that isn't there when the cars weight is on the tires.

Maybe from under the car, with it up, you can look for things that may show signs of being rubbed. Clean or shiny spots.

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Wednesday, October 29th, 2008 AT 6:16 PM

JLHOLDEN

MEMBER
5 POSTS

When you have it up off the ground the suspension is hanging down, not compressed with the cars weight on it so that could make clearence that isn't there when the cars weight is on the tires.

Maybe from under the car, with it up, you can look for things that may show signs of being rubbed. Clean or shiny spots.[/Quote:33e971a72e]

I was under the car for quite awhile tonight, and did not find evidence to indicate that anything was rubbing. Checked the wheel bearings just for the heck of it, and they were tight - just replaced them.

Did the stethescope on the trans, and could not hear anything like the sound (zzzdddd zzzzzddd -goes faster as you pick up speed). This tells me it is either transmission, axles, or wheels. I initially thought maybe the wheels were rubbing on the calipers, or maybe a wheel weight was rubbing, but there is tons of room between the wheel and the caliper.

I will pull the wheels off the front tomorrow after work and take another good look behind the wheels & in the wheel house to see if there is anything suspect.

Guess I'll just HAVE to ride the ZX-14 to work. ;-)

No strange noises or vibrations out of that machine. Lol right up to 170mph (so far).

Question: Has anyone heard of the transmission in these cars having issues like this rubbing / deep grinding noise?

I used to work at a trans shop in Flint Michigan, and have heard of other trannies having center support failures due to poor lubrication. But I have been out of the mainstream for a bit now, so I am not sure which ones are trouble these days.

Anyone run into this situation before?

I even had the tires balanced & rotated, which did solve a slight vibration between 60-80mph, but it didn't help this issue.

Maybe I will get lucky and it will be like a carrier / differential bearing or something that I can get to easily to fix (trans has a bolt on carrier housing).

Help me Car Pros!

No Gnews is Bad Gnews!

Please give me some good Gnews!

Thanks for your time (and great tolerance for my poor attempts at late night humor).

JLHolden

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Wednesday, October 29th, 2008 AT 10:27 PM