chattering noise in engine

i have a problem that started a while ago, when my car was in second gear it would have this chattering noise coming from the engine, at first i tried tranny fluid, didnt work, after a while i noticed that it only did it after i had hit high rpm once or when i down shifted from 3rd to 2nd it would get kinda loud. now it always does it in 3rd gear bad. but today i went to adjust my valves because thats what i thought it might have been, when i was wiggling my exhaust valve for the number 2 cylinder it kind of made the same noise. the noise kinda sounds like the sound that your car make when its in a gear that is too high and it kinda shakes and chatters. please help, this is driving me insane.

Could be a very bad worn valve seal. Or squirls, more than likely squirls.

hey dude!

I think the chattering your hearing may be the differential gears in your tranny...mine does the same thing in the high rpm range in both first and second gear...doesn't matter what kind of stuff you put in the tranny..what can you say...these things are old

I had a chattering/ shuddering in my car when the cv shaft started coming out of the intermediate shaft, it would do it after downshifting at first, and usually only while cold...but then started to do it more and more, the splines were half way out of the hole....because the spring clip was nowhere to be found...

hey dude!

I think the chattering your hearing may be the differential gears in your tranny...mine does the same thing in the high rpm range in both first and second gear...doesn't matter what kind of stuff you put in the tranny..what can you say...these things are old

sounds like this may be it, my clutch is also about dead