95 Grand Prix rear noise

[Melanie1854]

My son's 95 Grand Prix GTP has a low rumbling (?) sound coming from what sounds like the back end. It is almost like a bad bass speaker, but the sound is not coming from the speakers and is audible when radio is off. Had the rear tires pulled and put on rack for check..saw no problems but said the tires were kind of squared (an unbiased third party tire store said "not true"). Can only hear it at low speeds, but I'm sure it is there all the time, just inaudible due to speed. Any ideas? Rides fine, just concerned for young driver's safety. Thanks for any suggestions. Melanie

[slacker_53]

The only things at the rear of your sons Grand Prix that can make noise are 1) tires.....2) wheel bearings......3) brakes.......and lastly 4) fuel pump

With the noise you are describing, I would put my money on tires.

Do this, swap ends with the tires.....put the front on the back and the back on the front and see if that changes things.

That is probably the most inexpensive thing you can try.

Tires on the rear of the car, if their not rotated from time to time, will wear in an odd way because all they do is roll around and brake. The front tires will wear much better because they have torque applied to them contantly, keeping their wear pattern more true.

-slacker

[Melanie1854]

Thank you! I will send him your suggestions. Guess those tires might be the culprit after all. Really appreciate the feedback!

[kilroypr]

Well, I get the almost blown woofer sound from time to time and in my case is that the OEM exhaust system has some metal covers over the resonators and other parts of the system and with time they tend to loose a little and when idling or slow acceleration you can feel it since the oscillation on the exhaust system is higher do to a lower air flow and consecuently you feel the ratling noise

[slacker_53]

Originally Posted by kilroypr

Well, I get the almost blown woofer sound from time to time and in my case is that the OEM exhaust system has some metal covers over the resonators and other parts of the system and with time they tend to loose a little and when idling or slow acceleration you can feel it since the oscillation on the exhaust system is higher do to a lower air flow and consecuently you feel the ratling noise

If your rattle is comming from your cats, the cats have an 80,000 mile warranty. You can have them replaced.

-slacker

[kilroypr]

is that real? I tough would be 36 months/36k miles on all parts

[Melanie1854]

Interesting idea. I already emailed him and asked him to rotate the tires. I will let him know about this other as well. I really appreciate the advice! Many thanks.

[Melanie1854]

Now do either of you know anything about those ridiculous auto thermostat heaters in the 97's? I have one that is out of the twilight zone! (Gimme a knob any day!)

[slacker_53]

Originally Posted by kilroypr

is that real? I tough would be 36 months/36k miles on all parts

Emissions (of which the cats are part) have an 80,000 mile government imposed warranty. Now if the outter shields are rattling you may not get them replaced. But, most rattles in the cats are the guts coming loose, that is replacable under warranty.

-slacker