I've got a 99 Cherokee Sport..thats making a strange noise at idle.Its like a low rumble that I can only hear in the vehicle.I first thought it was a loose exhaust vibrating on the frame but everythings clear on inspection.The motor runs like a champ and the noise seems to go away by itself.When I put it in gear I can hear it sometimes and when I shift to park it stops.I tried reving the motor to see if it got worse but it didn't...I've heard of flexplate problems with the auto transmission...anybody had to tackle this? I was also thinking maybe a bad motormount..the tranny mount looks fine...

 

Get a 2x4 and try to move the engine, if you can move the engine real easy you may need to change your mounts. For the flex plate crawl under your rig and take the inspection plate off. You can check for loose bolts (4ea) on your flex plate and you can also look for cracks in the plate (get a flash light). The cracks tend to show up around the mounting bolt holes.

 

start basic. fluids good? tune up situation? any thing else? mileage on jeep?

 

Its a 99 Sport I bought for my my kid...its got 150k on it.I've done a ton of work to it but this is driving me nuts.First I thought it was the exhaust manifold because the PO told me it was bad.I tackled that and the noise still is there.I've done the water pump,new radiator..all the tune up basics.I replaced the tranny line because they looked banged up and all the brakes and both front hubs.I've been reading through the threads and I think it may be the flexplate bolts..