I noticed that my Jeep has been making a distinct clapping noise any time the engine is not up to operating temperature. It sounds worst on cold mornings, but becomes quieter as the engine warms up. The noise is RPM dependent, so I’m assuming it has something to do with the engine. The noise is not …

Jeep cold engine noise

VDCdriver December 24, 2011, 3:39am 4

Yes, all of the lifters would need to be replaced, if they are indeed the source of the problem.