Okay folks. I have an 85 monte carlo ss that is mostly stock and original. On my drive to work this morning I noticed a slight thumping noise as I accelerated. It doesn't make any noise when I am standing still. And it gets faster as I go faster. I will put it up on jacks and do real diagnostics tonight when I get home. I'm just looking for your opinions on what it could be so that I don't waste time checking things that it isn't.

1. something in the tire. I inspected what was exposed when it was parked. It could be a rock in the tread and on the 15% of the tire that's touching the ground.
2. u joints. They are original after all.
3. wheel bearings. I don't know if they're original or not. I replaced the lower ball joint a while back but managed to do it without taking the rotor off.

Any other thoughts? Also these tires have been on there since I bought the car. So I know there is a slight chance that there is a loose belt in one right?

Thanks guys,
Andiamo

 

Make sure your lug nuts are tight. I had a sound similar to what you are describing not to long ago and I had a couple of loose lug nuts. Hopefully this is the easy fix.

 

If it sounds similar to having a flat tire it could be that one of the belts in the tire has separated. You can do a quick check for this by swapping the wheel with the rear one and see if the noise/vibration transfers to the rear of the car. If it does you need new tires (replace both front at the same time). If it does turn out to be a separated belt get it taken care of asap. Driving on it is dangerous as the tire could burst at any time.