teeonehundred

so i landed a new jeep an 88 pioneer (gave it my version of a torture test) and just seems to be great HOWEVER on crank up it revs unusually high about 3500 rpm's to 4 grand (i hooked up a tach to it so i can see the rpm's) it sounds like a diesel running like crap. so i get out the ole stethoscope and listen to the bottom end and top end, it's almost the same sound as a bad rod bearing, knocking and all but the odd thing is i hear it from the top end much louder while listening with the stethoscope, i was 100% sure it was a bad rod bearing but now im not so sure the same sound comes while driving but go's away while accelerating but once i hold it at speed it'll be there but not as loud and when i let off the gas it stops, any ideas on what to check or how to check them? gotta do a rear main so i'll check the rods while im there for slop. would a dropped valve or bent valve make the same sound? thanks guys!

joe bob

valves could do it but try your stethiscope on the passenger side of the engine and give your camshaft a listen, if it seams thats where it gets the loudest pull the timing cover off and check for slop in the cam, mine ran great but the cam moved in & out about a quarter inch. needed new bearings

teeonehundred

check the sound at, i'll pull that cover today and let ya know what i find. thanks for the tip!
-happy