Clunk/pop on start up

I've got a 98 xj with a 4.0l, aw4, 68k miles. Every once in a while, when I start it up, it makes a clunk right before the motor starts up. The noise occurs when I'm cranking the starter, and it sounds like its coming from the driver side of the engine compartment. Almost sounds like a backfire, but when it starts up (after maybe 2 seconds of cranking) it runs fine. No CEL.

Anyone experience this?

Erik

I'm willing to bet its a motor mount.

Thats the only time it does it though, during start up. If it was a motor mount, wouldn't it do it when i was driving? I do drive/wheel pretty hard.

Could be your cat. Mine did that for years until I replaced it and notice that the clunk had disappeared. The innards of the cat had totally separated from the body and was rolling around in there like a rock.

Try and put it in 4x4 Low range and get on it hard.....if it is a motor mount, you will know then.