Keatonsdad

Hi all im new tho this site and hope for some answers or solutions,
we have a 95 grand cherokee with right at 100k on the original motor, recently we were using it to pull a trailer and of corse it is going to work a little harder and run a little hotter, well once it got to 210 we started to hear what i think is a lifter nocking. we pull over i check everything (fluids for metal shavings, etc....) everything is normal, get back in and start it up and the noise is gone. Strange but ok, we are driving around yesterday looking at homes and the same situation happens all over again. so im going to flush the cooling system and check the lifters but in all of my years of wrenching ive never had this happen, we are just hoping its not in the bottom end or anything that constitutes a rebuild. thanks for the help in advance
Mike

4.3L XJ

You probably did hear a lifter. When the engine gets hot, the oil thins and then a little wear will show up. Many of these modern oils are just too thin for older engines. I run a 20W50 oil and never have any problems like that. The thinner oils were added at the factory to boost milage to make it past EPA requirements. A little heavier oil will make your engine last longer. I know others will argue that, but a 95 engine was not really designed for these new oils that are like water at operating temp.

$800XJCherokee

Put in LUCAS TREATMENT. Frees stuck lifters and gives you some additional protection.

Keatonsdad

im running a full bottle of lucas with mobile1 10-30 and it still does it i think on the next change ill try the 20-50and see i know its kinda thick but we are averaging 98-105 temps with 110-120 heat index so it might not be to much i am also going to do a coolant flush and fill when i do the next oil change im going to let the lucas do its job for a little while and hope it frees things up i also did a sea-foam treatment to it with the last oil change s this might help as well

4.3L XJ

Dad

Lifters are not usually "stuck". They operate off oil pressure. So if the oil is thin, or the clearance between them and the block is worn, then the plunger in them collapses and when it hits bottom you get a tick. The idea of the thicker oil is to increase your oil pressure and keep more oil in the lifter as well as force the plunger up to where it should be. 20W50 is a multi viscosity oil that performs well down to 0°

rich

Boy oh Boy your motors must be wore right out, lucas and 20w 50 dam that is thick your clearances must be about 1/4 inch(overboard a bit).I tried the recommended amount of lucus and it was to thick it was rattleing.I had to change the oil back to just 10w30 and no additive.

Keatonsdad

she has 100k on the clock and its a 95

4.3L XJ

I think you misunderstood. I use 20W50, he used the lucas. You shouldn't use them together.