91 4.0XJ
NAXJA Forum User
- Location
- Chicago IL
Do 4.0's have roller lifters?
Eagle said:Sure, they could be, if the oil wasn't changed very regularly.
On the other hand, my '88 XJ is at 247,000+ miles and I don't think the cam and lifters are worn out. Worn, sure, but not worn out.
If you want a cam ... buy a cam. Just remember that dropping a new cam into a 170,000 mile engine is asking to blow up the engine. If you want to go with a more powerful cam, you really need to "freshen up" the engine at the same time you do the cam.
Some folks have replaced the rod bearings (rods only, not mains) and found them worn down to the copper backing. If the oil is changed regularly this should not be a problem. If you have abnormally low oil pressure, that's where to start.91 4.0XJ said:Do 4.0's have any common high mileage related problems? (oil pump, timing chain, lifters)