1989 Jeep Cherokee TAPPING IN MOTOR

The jeep inline 6 is a great motor and can go alot of miles with regular service and maintenance. But somtimes things just where out and weaken over time. Sounds like a lifter has just gotten a little weak. After being driven awhile it quites down. Just normal wear on the lifter itself could cause this or it might be getting a weak oil pump. Probably not. Also the pushrod for this lifter may be clogged up a little and not passing the proper amount of oil. What weight of oil are you running?? You may add some STP at normal oil changes and lesson the noise a little, and you might need to tighten the tappet down just a touch on that one valve. The whistling??? Is this in the engine compartment?? Sounds like a vaccuum leak to me. Check all your vac lines in and around the intake. Let me know if this helps. Curt

ADD THIS TO THE GREAT ADVISE THE TECHNICIAN HAS GIVEN YOU. I HAD A KNOCK IN MY JEEP ENGINE AND THOUGHT I HAD SERIOUS PROBLEM. ON A WHIM I JACKED UP TRUCK REMOVED FLYWHEEL INSPECTION COVER AND CHECKED TORQUE CONVERTER BOLTS AND 1 HAD BACKED OUT TAPPING BLOCK.I WAS A HAPPY CAMPER. MAY NOT BE THE CASE WITH YOURS BUT WORTH CHECKING.

thanks for your input