Replacing head gasket on 90 XJ

[PolloLoco]

I got a 1990 XJ for free, the catch is that it's got a blown head gasket. It'll be good practice for me before I stroke my TJ. What I want to know is just general info on replacing the head gasket. It should go:

• drain coolant and drain oil
• pull the valve cover and pushrods
• clean the block and head mating surfaces
• check the cylinder head for warping and cracks
• install new head gasket
• install the head, push rods, and valve cover

Does that sound about right? Can I replace the head with a HO head and keep the Renix intake/exhaust with EGR? I will be subject to emissions testing.

Do I have to send the head to a machine shop to check for warping and cracks or is that something that I can do myself?

Should I replace the valve seals?

I might as well flush the cooling system, should I do that before or after I replace the head gasket?

Do I need new cylinder head bolts or can I reuse the stock ones? I don't know if they've been reused once yet so I'm inclined to just get new bolts.

This XJ will be my DD while I stroke my TJ, I'm not going crazy with this thing.

Other than the fact that it leaks coolant it's a good running XJ.

[Muad'Dib]

I did this to my 90 a few years back.

You have the basic outline of what needs to happen.

Mine had a broken exhaust manifold bolt, thats why i took the head off.

Dont worry about trying to upgrade to a HO head. Its a little more involved.. and not really worth doing on an 150,000+ mile engine.

Your going to want to flush the block, heater core and radiator the best you can when the head is off. At least thats the way i would do it... so i can get as much contaminates out as possible. I would also do it again after i bolt everything up.

My head bolts were also unkown, but its best practice that if they have been re-used they should have a paint mark on the tops of them. Mine didnt, so i assumed that they were good. If you really want to be sure, go ahead and replace them. I only had enough money for the gaskets, so i couldnt spend any more money on the bolts... they ARE expensive. Im assuming your on a very tight budget, so id just re-use the old ones this one time.

Make sure that you pull the pushrods and rockers in an order that you can remember. They need to go back into the same spots they were pulled from.

Of course check everything for any abnormal wear...

Again this is assuming that you have very little cash to throw at this project.

Since you had a blown head gasket, it might well be worth taking it in and making sure the head didnt warp.

If i were to do it all over again, i would get the head cleaned and get a valve job done along with replacing the valve seals. I would also replace all the rockers, pushrods, and lifters. (You CAN replace the lifters with new ones without replacing the cam). Reason being is that about 8 months after i did this job, i developed a knarly tick up top that i am attributing too some worn parts.

Oh one more thing before i forget... replace at least the motor mount on the drivers side since you will have the manifolds out of the way (im betting its worn). Also check the exhaust manifold for cracks (It probably is) and replace it at the same time. Dont forget about proper head and exhaust/intake manifold torque sequence.

[PolloLoco]

I'm not on a tight budget, but the less money that I have to put into this XJ the better. I am scheduled to arrive back in the States on Thursday, deployments bring extra cash and I have a promotion a few months down the road.

I found this:
http://www2.partstrain.com/store/detail ... 076PT.html
I'll get that and a set of head bolts.

I'm not going to bother with replacing the lifters, push rods, or rockers. If I get ambitious I may do a budget stroker on this Jeep in a year or so, but that's only if I decide to keep it when I PCS to Ft. Leonard Wood.

[Muad'Dib]

You do have a manual right? So you can get all the torque specs and sequence?

[PolloLoco]

I just bought one online today. It should be at my house by the weekend.

Now the problem is finding a head bolt set for a 1990 XJ. I can only find head bolt sets for other years, 87-96 don't show up so easily.

[Muad'Dib]

Try felpro part # ES71102

http://shop.oreillyauto.com/productdeta ... er=ES71102

They are for the later MY, but they should work fine... or at least i dont see why they wouldnt.

You could also try headbolts.com


http://headbolts.com/chbs-1128.html

[PolloLoco]

Looked up the head gasket set and cylinder head bolts at the Schucks (O'Reilly) near my house and they are cheaper than AutoZone and offer a 10% military discount. Parts will be less than $100 out the door.