engine noise
 

hi after the engine is fully warmed up, I don't rev it when its cold,
It revs nice from 1k to 4500 but after 4500 rpm I hear a rattling clanking kind of noise. what could this be. car is not under load, as its still up on jackstands. Its a 1984 944 NA
thanks,
Jason

explain this noise a little more...is it from the engine/block/head? Around the engine? Tranny tunnel? Belt area?

Beings it happens so high up in the RPM band I would assume it's either something loose or your timing is off slightly. Why is the car on jackstands? Why are you free-revving a car on jack-stands?

Could be a bad water pump, tension pulleys, cam gear loose, broken clutch disk or pressure plate, throw out bearing, drive shaft bearings, power steering pulley on the end of the crank, idle pulleys (smooth ones). Could even be a loose framzel washer.

LOLOLOL I think what Socal is trying to tell you ....

... noises are hard to diagnose

so too add to this list........ it could be a the car rattling against the jackstands that it is mounted on....... :eek:

ok, well i guess i'll have to get the car off the jackstands, and start driving it to see where the noise is, the car is on jackstands because i bought it non running (i now know that i paid way to much for it) because it had sat for over 10years. I have the car almost road worthy now, with the timing belt how much could it be off and still run? as i could never find the top flywheel mark in the bellhousing, i centered the botom one and set it, then hand turned the engine over and felt no resistance so i though i was good.

You have to find the correct timing mark on the flywheel. Take the cover off of the bottom of the bell housing and turn the flywheel over with a large screw driver. Taking out the sparking bolts helps. Use a bright shop light. When you find the OT mark rub chaulk into it.

Check your belt timing including the balance belt. You could have a pulley on 170 degrees out and get some high rpm vibrations.

One thing you need to check right now, beings you never could find the propper fly mark, is that the valves aren't contacting. You need to make 4 full rotations of the crank with a wrench by hand and make sure that there is no direct interference in the travel.