Ok, I need some serious help!!

I have a 2003 Jeep Grand Cherokee 4.0L petrol straight 6, now I have been suffering with a loud tapping noise that I would normally say is the tappets, but this only happens when the engine is cold then gets louder then just stops when the engine warms up, the tapping does not fade away, it just stops dead!! like a switch has turned on! got to add that you do not hear this when you 1st start up, only after a few seconds (10-15) the tapping starts.

But also when the engine is warm, you can hear this tapping (not as loud) in cycles, see if i can put this in to words!! the tapping starts off softly then builds in loudness, then just stops, again like a switch has tripped, then it does this again and again!!

Have had this checked by Chrysler - !!!! no help yet!!

Can anyone HELP!
Martin

 

mine also taps alittle in the morning it goes away when i hit the gas a few times .then its off like a switch the rest of the day .i want to make sure the channels are clean for the oil they might be blocked

 

What brand of oil filter do you have on it? When I bought my current 98 XJ it did the same thing. It had a Fram oil filter on it. I changed out the filter and it went away. You want to run a Wix, Napa Gold or a Mopar filter. Fram filters are garbage and can cause a lot of problems on our Jeep 4.0's.

 

Two things tap on our Jeeps lifters and or piston skirts. The problem is usually the first. Use an oil filter other than fram some MMO or CD2 oil detergent, the tap may not go away(it's usually there to stay)
Bought my 90 with the tap at 248,000mi
now at 433,000 still tapping.