OK, I'm new to the site but not new to trucks, this jeep is my new DD.
I have an 98 ZJ with 203K miles and I need this Jeep for the next 10 Years, 20K per year, ten years 400K.
It has a bad head gasket, needs injectors, so I think I want to replace the head (reman or junkyard rebuilt?) and gasket, injectors, timing chain.
I'm willing to spend a little I just would like the short block to go 400K.
Any recommendations on the order of work or parts selection?
I would be a fool if I did not tap into the knowledge within this community.

Thanks

 

I'm assuming this is a 4.0? Okay, I just looked at your profile block.

One word of warning. When you put a new or rebuilt head on an engine with worn rings, you increase cylinder pressure high enough that the rings may not seal as well. My advise is to just drive it until you start to have a loss of power or start using too much oil. My WJ 4.0 had 156K on it running perfectly, then the head cracked. This is the questionable 0331 head that everybody talks about. You need not worry about that with your ZJ. The point is after I replaced the head with new valves, it started using a lot of oil! It was/is coming thru the CCV into the intake manifold. It only seems to be a problem at idle when the vacuum is very high. Going down the road or even descending hills it doesn't smoke, just at idle. It seems to just be cylinder #5 that has a problem.

I replaced my injectors with 4-hole Bosch only because the outer cases of my OE Sieman's were cracked. No noticeable improvement in MPG, but a much smoother idle and quicker throttle response. I replaced the timing chain at 225K miles and it hadn't stretched much at all. She now has 238K on her and still runs strong, as long as I don't let her idle too long, then she'll foul a plug. I'm going to put an oil catch can on her pretty soon in the hopes of stopping that. She's still holding 40 psi oil pressure at idle hot and 55 psi at 60 mph.

 

Yes Dave, it's a 4.0. It's really going through water, a gallon a week and number one Cyl plug is always the first one to foul and trigger a misfire code. I guess I really need to do a compression test to confirm that its a bad head gasket.

Thanks

 

Added a OE belt from the junk yard today, the other belt was new and made too much noise, must have been cheap in quality.
It was not cheap in price. Used OE belt is much better and I have a continental belt coming in the mail.

 

Where would I find the casting number on the head 4.0L ? Intake/exhaust side? Distributer side?

 

It should be molded into the small flat between the valve cover and the intake manifold, just aft of the center. I have a picture of the 0331 "TUPY" head that shows the number in the upper left corner. Your's will be a different number that escapes me right now.

 

Thank You! This is very helpful.

 

Ok, you guys remember as kids we would take a clothes pin and position a playing card in our bike spokes, remember that sound?
Well after doing brakes on my ZJ, rotors and pads, front and rear. I'm getting a noise just like that. Brake performance has never been better, but there is this noise that's a little strange.
A frosty Coors Light salute to any good ideas.

 

Check the e-brake shoe hold-down pins. The shoes may be rattling around inside the rotor. The hardware tends to rust up if it's not used.

 

That's what I'm looking for, I'll bet you're right, I did change out the e-brake shoes.

Thank You

 

So the other day I hit a pothole and heard a snap! The jeep started handling strange.
I thought it was the front right sway-bar link, sure enough I had a look under the front and could see the cheap link
I had replaced 6 months ago was junk. I installed a pair of Moog links the kind with the ball joint and everything seems fine now.

 

Is there any way to change the title of this thread, Mods ?
It should read "98 Jeep Grand Cherokee 203K to 400K"

Thanks

 

Going to drop the tank and change the fuel pump today, film at 11

 

Try taking the #1 head bolt out and coat it with #2 red loctite. Then torque to only 100 lbs, not 110 like the others. The bolt extends through the water jacket and this is required. Not sure if it will make any diff but worth a shot?

 

Holey donuts, Batman! In extreme cases, that bolt will crack into the cylinder if overtightened enough. Good catch, although like I said the possibility is slim.