My 89 XJ has a blow by problem that most of theses XJ's do. It doen't have a ton of miles on 115,000 or 120,000 can't remember right now. The blow by is extremly annoying and I think it's cause a loss of MPG. Can I just replace the rings on this engien since it has fairly low miles. I wouldn't think a complete rebuilt would be in order. What do you guys think?

Is your motor a 2.5L or a 4.0L??

I have a YJ with a 2.5L with the same problem and i am also wondering what to do

Thanks

You can, but if it's a 4.0 it's just as big a bitch to do one set of rings as it is to do the rest. You're probably going to end up having to pull the engine and once you do that you might as well rebuild.

J. J.

If there is enough wear for excessive blowby, it is not just the rings, it is also the cylinder walls. You can put new rings only in it if you really want to, but you may end up with a worse problem than you have now. 120,000 on a 4.0 is about rebuild time anyways.

[ 11-03-2001: Message edited by: JeepinIan USA ]

Yep, I have the 4.0 and from what I've been hearing you might as well do a full rebuilt.

Might not have to rebuild Here you guys go.

I had some blow by. I pulled the valve cover and cleaned all the baffles on the breather holes in on the cover I didn some other stuff that I can't remember and now I have no blow by.

I have 146,000 original miles on my 4.0 1990 XJ

Check this link out. http://www.off-road.com/jeep/cherokee/xjtech/engine/40ltr/blowby.htm

check out www.jeepnorthwest.com in the cherokee section. they have a good writeup about blow by. Unless your motor is losing power and burning oil, the rings probably don't need to be replaced.

This doesn't work for me as I have the 4.2 (1987, pre-FI), and anyway my problem is very likely the rings as I have already cleaned out the valve cover from the inside out and replaced some hoses, PCV valve, etc.

So as a last resort, I attached a very long hose to the breather in the back of the valve cover, and ran it all the down past then engine, under the frame, and just over the tailpipe. The oil still leaks, but now it's nowhere near my engine and most of it burns off on the hot tailpipe when I park it.

Too much of a jerry rig for my taste, but it'll do until I have the time to rebuild the engine - or swap in the Chevy SB. In your case, I'd try the other fixes first, of course, but if it doesn't do it maybe this will buy you some time before the rebuild.