unibrowlad

Hi everyone!

New here, and looking for some help.

My 2008 3.8L has developed quite the ticking noise, too loud to ignore. It started very suddenly about a week ago.

I started at the exhaust manifolds and they both appeared to be cracked so I replaced them. The noise did not change much so that leads me believe it is the infamous lifter tick.

I tried to narrow down the location of the tick with a stethoscope but didn't find anything definitive with that.

Tonight I removed the valve covers to inspect and everything under there looks and feels good, I didn't feel too much play in the rockers.

Is there another way to tell if one of the lifters is bad? Should I dig deeper? Or should I turn my attention elsewhere?

TIA for everyone's help.

Jay2013jk

Welcome to JKF. I've been on forums for several years and I have not read of any lifter issues with the 3.8L engine; not saying not possible. What are the Miles? Cold engine or HOT or both Does it speed up with engine speed?

Islander2010

I’m right here with you. Engine tick after warm up. I’ve tried all the oil tricks, I’ve replaced both exhaust manifolds, I’ve replaced the timing chain and oil pump, I ran the engine without the belt, I’ve pulled the valve covers and everything seems tight. I’ve checked rod bearings the best I could when the oil pan was off. I’ve tried pushing down the pistons with a screwdriver. I’m really not sure what else to do. Tick/knock seems louder under the Jeep. Stethoscope has so far not been helpful in finding this noise.


2010 jk 3.8 auto

Islander2010

ended up being rod bearings. I switched them out and all good now. It sure sounded like lifter tick, but looking back it was louder underneath the Jeep.

Mr.T

I've used xW-40 oil for over 200K miles, the rod bearing clearances on this engine (and most engines of this era and older) are most often going to be on the loose end of the mfg tolerance -- Which in this case is appropriate for xW-40. For reference, Driven Racing oil has a viscosity chart based on bearing clearance and oil temperature... It's info that hasn't changed much in 50 years.

Anyway, if one suspects mild knock from worn bearings: Raise the oil viscosity and note the affect, simply adding a bottle or two of Lucas can help with diagnosing. If the increased viscosity doesn't have any affect, the noise is probably not in the rotating assembly.