As pevious posted under: Hammering / knocking noise on 4.0L6 '99 Cherokee it seems, I am much closer to finding the source of the noise now. For the last hour, I have spent listening to the engine at idle, air-con and auxiliary fan off.. No mistake, the noise is coming from the engine, around cylinder 5 or 6. The noise is also clearly audible around the left wheel house. It cycles on and off. It goes like: tick, tick, tick....increasingly loud for about 10-15 seconds, stops completely with a few seconds silence in between, and starts again. The cycle lengths are not completely even, with variations of within a few seconds. Some cycles are louder, some cycles softer, and sometimes, there is a longer brake in between the cycles.
What could that be?
Thanks again. I feel, I am much closer to solving this riddle now.
Regards,
Robert