Slight engine knock at idle on 98 TJ 4.0

[olperry29]

Hi everyone new to the jeep forum. I have a 98 jeep wrangler with 77k miles and have a slight engine noise at idle that i can hear in the cab but outside i cannot here it. When i accelerate is seems to go away any ideas? oil pressure is above the first line at idle and goes above 40 while driving.

 

[Chris]

More than likely it’s the very common exhaust leak or lifter tick.

 

[olperry29]

i though so to but it sounds for internal and it doesnt have a tick it more of a knock. checked the oil this morning and levels are fine

 

[BrunoPizz97]

VIDEOS!!!!

 

[olperry29]

i will try to take a video today not to great with tech haha it is not a load noise i might be very anal with a jeep that is 21 years old. it does have a rear main seal leak but i checked oil and levels are good. i drive this on the road daily and wheel it pretty hard on the weekends.

 

[Goatman]

These straight 6's are very common to have a slight knock or tick. All of them. The Ford 300, Chrysler 225, the Nissan and Porsche are even known for a slight knock at idle. If you have good pressure and the engine runs strong then I wouldn't worry too much about it. If it gets loud or stays throughout the RPM range then I would look for a cure. Think of it as your engine saying hello.

 

[olperry29]

Thanks goat man good advice!