Head gasket

I have a 90 XJ 4.0L with 160,000 miles and a leaky head gasket. I plan to replace the gasket this weekend. Is there anything I should watch for?

Yea....watch your back!
That sucker is heavy,have a buddy help to lift it off.Unless you are a burly guy,ofcourse....

Oh,and welcome to naxja.

Service the manifold and gasket while you've got the head on the bench - it's MUCH easier there (don't ask how I know...)

Torque specs and fastener data can be found on my website.

It's possible to lift that head up lone-handed with the manifolds attached, but you'd better be big to do it. It is easier to deal with the manifolds if you remove them with the head, tho - even if you have to get help to do it. Also, watch for the driver's side rear stud - you'll want a mid-length socket for that one.

And, if there are paint marks on your head screws, get replacements now. If there are not, be sure to put paint marks on them - AMC242 head screws are only good for two torque cycles.

It's a good time to clean out your intake manifold. Personally, I'd take the head in to get reconditioned.

Spray WD-40 or PB Blaster on all the hi-temp bolts once or twice a day before doing the job. preferably before and after driving the vehicle (if your not driving it, then run the motor for 20 minutes each day if you can safely). The heat cycling with penetrating oil does a lot to free up any seized bolts and help prevent any snapped off. The bolts on the exhaust pipe to exhaust manifold and all the manifold bolts tend to seize from the heat.

Make sure the block and head surfaces are thoroughly cleaned and straight.

If you haven't replaced the valve stem seals, now would be a perfect time to do it. Any engine, the valve stem seals rarely make it too 200k, if yours aren't leaking now, they will be soon.

Thanks for the info. By the way, That f*$#&ing head is heavy.

Fly the head off and on. Works great, no back strain. The load lever from Harbor Freight was only about $30. In the pictures the head is stationary and the jeep had to be rolled back and forth which keeps the head from swinging. As you can see the radiator and grill are out but you could probably do it with them there, just have to come in at more of an angle. Use a 2x4 or a rope back to the back bumper to pull the hood as far back as possible or take the hood off.

You can gently lower the head down and use the load leveler to keep it in parallel to the block until you can touch the back of head down and then let the rest down.

X2 on assembling the head and mainfolds on the workbench over in the vehicle.