77 Nova makes noise when in park?

My son has a 77 Nova with the 6 cylinder and auto tranny. He called the other day and said it made a pop noise and he could feel it in the accelerator. He stopped checked the oil and it was really low, fill it back up to full. It started right up, but make a knocking type noice when in park, he decided since he was a mile from home he might as well drive it since the damage probably was already done. He put it in gear and drove it home, it never made a noise all the way home. Got home and put it in park and it made the knocking noise again. Anyone have any ideas, he lives 300 miles away so I don't have access to the car. I told him I would check around to see if I could find anything out.

Any help appreciated.

Thanks,
Bob

Something could be wrong with the transmission. I would tell him to definatly check the Transmission fluid and see what it looks like. If its dark brown thats not good also if it smells burned. Even if the transmission fluid isnt brown or smells burnt, i would get it checked out anyway somewhere, like AAMCO or some automotive place. GOOD LUCK!

Universal Joint. Does it do it when he shifts into any gear? My guess (90% sure) would be a U Joint from the way you describe it.

Rob

Damn you know what I didnt even think about that. I totally agree with Rob.

u fudged your oil pump now things are banging

If it only does this in park, and not at all in gear, I would look at the flexplate and the torque converter bolts. The flexplate could be cracked, and the converter bolts could be loose. Causing it to rattle or knock when there is not pressure on it (in park or Neutral), and causing it to stop when there is pressure on it, or when it is in gear. My 88 pickup did this.

If it only does this in park, and not at all in gear, I would look at the flexplate and the torque converter bolts. The flexplate could be cracked, and the converter bolts could be loose. Causing it to rattle or knock when there is not pressure on it (in park or Neutral), and causing it to stop when there is pressure on it, or when it is in gear. My 88 pickup did this.
i had the same problem.... in park or neutral id hear this knocking noise
took me for ever to figure out the problem...
this is what i found

http://www.geocities.com/simplebliss107/broken_parts.html

I've seen this before, my $$ is on a cracked flex plate. Get under the car safely, drop the flywheel inspection pan. See if anything fell into the pan first. Make a chalk mark on the flywheel, rotate the engine around and look closely with a flash light, you should see a crack or will be able to tell if the converter is loose.

Bob