Search results

Well my "new to me" xj that is tapping at idle has a broken #6 piston skirt. We found pieces in the oil pan. Sounded exactly like a lifter tapping. Only made noise at idle. $600 engine from the salvage yard with 130k miles on it, and $500 labor at the shop and im back in business.

Old thread! I never did fix it. I Sold the jeep 6 months ago still tapping at idle. It never got better or worse. Flexplate wasnt cracked or loose. Im thinking its a collapsed lifter. Fast forward to now, I just brought home a new to me, built, 97 XJ. It has 130,000 on it, and guess what, it...

OK i just went outside and fired it up for the first time today. Its about 30 degrees outside and the engine and oil were cold. It was perfectly silent for about 5 minutes of idling. Then slowly an intermittent clicking started. Then as it got to operating temp (about 8 - 10 minutes of idling)...

I havent checked the purge valve but it never crossed my mind! I will go out and check it right now. What does it do? and why would an oil change affect it? Also, would plugging off the CCV inlet change the noise on that thing?

The CCV that Im talking about is the one at the front of the valve cover. Its not even really a valve...Just an open elbow. It has a plastic tube running over to the Air filter box. The noise seems to match the RPM's. Its not a solid sound like a "hammer smacking an iron block" but its loud...

98 XJ, 4.0, AW4, 139,000 miles I have a pronounced Tap/knock at idle that can be heard from several feet away and even in the cabin if you turn off the radio. I changed the oil and added 15w40 Rotella (Ive heard good things about the ZDDP, etc)and a quart of lucas to hopefully quiet it down...