Blown Head Gasket

[Ken]

How much trouble would it be to replace the head gasket on my 97 XJ by my self.

The shop quoted me about $400 to do it.

Is this reasonable or would it be a doable shade tree job.

Any insight would be great.

Thanks,

Ken

 

[AZ Jeff]

Doing a head gasket by yourself is within the realm of a decent amateur mechanic, assuming the following:

1. suitable tool set, including wrenches, sockets, breaker bar, extensions, and a TORQUE WRENCH
2. knowledge on how to properly remove/install components that have critical gasket surfaces, using proper tightening sequences, etc.
3. a buddy will probably be needed to lift the head out of the engine compartment. In line six cylinder heads are LONG and HEAVY.
4. I would have the head checked for warp while it's off. Most machine shops can do this easily for a modest fee. Also, depending on the age/condition of the engine overall, having the shop do a "head refresh" might be a good thing. (Reface valves/seats, new guides, new valve stem seals.)

Figure with hand tools, it will take you 4 hours to get the head off, and another 4-6 to get it all back together. (Air tools cut this time down considerably, at least in the disassembly phase.)

 

[Judd W. VA]

First of all........

Make sure it is the headgasket. Get a second opinion if necessary. To be a '97 and a blown hd gask the vehicle must have been run hot or something most cases, or is unusually high mileage.

Have not done specifically a 4.0 hd gask but all heqd gasket jobs if done well require some time, effort and knowledge if desiring to last a while. Is usually desirable to have head surfaced at a good machine shop to assure a good straight head surface. To have the valves ck'd is also a good thing when the head is off. Need to clean head bolts thoroughly with a wire brush and to chase the bolt holes in the block to assure good torque application in addition to all the other things.

"Slamming a head" is what is known in the industry to simply remove the head, clean surfaces, and to reinstall with new gasket. Is not a good thing to do and would not go to any shop that does that kind of work.

 

[Ken]

Well it ran hot add that is what I suspect did it. The water pump went, threw the serp belt and was a nice mess. It continued to run hot because the electric fan was not working properly with added to the problem. It has 104k on it and has been nothing but problems lately, the 5 gear syncronizer when a few months ago, then the water pump, then the head gasket.

Although I love the Jeep I think it is time to let her go.

 

[AZ Jeff]

If you had the engine overheat to the point of blowing the head gasket, I would DEFINITELY have the machine shop give the head a thorough once-over.

Unfortunately, at 104K miles, you are also at that point where, depending on the condition of the "bottom end", you may or may not want to consider working on that as well.

What was oil consumption like prior to the meltdown? If it was nil, then maybe just doing the head will be OK.

If you decide to dump the vehicle, keep in mind that a Jeep with a "dead" engine is going to go for a low-ball number..........

 

[ChiXJeff]

I did a head gasket on my 94 XJ last October, the day before I left for the Moab Fall Fling.

5-6 hours alone. Hand tools, no hoist. Yes, the head is heavy and cumbersome.

I picked up a remanned head through Autozone for $200 net, all it needed was a pair of manifold alignment studs. This made it easy as I didn't have to wait for mine to be machined and rebuilt.

I actually did this twice, head gasket alone in October, then replaced the head a couple of months later (long story....... and it involved chewing a new excretory orifice or 2 at AZ.)

One side note, and this applies to more than heads. Make sure that the manifolds seat all the way down against the head. I've had trouble twice with something hanging up on a bolt thread someplace, and doing some jiggery-pokery to get it down.

ChiXJeff

 

[Rags]

After you get the head off..look at all the cyl bores...overheating can destroy and scar the cylinders.................Head gasket job labor wise takes about hour and a half to 2 hrs if nothing breaks.............air tools speeds things up..........I would send out the head and have a valve job done,new valve seals and decked................also good time to examine the exhaust manifold and replace it if cracked.....................

 

[Judd W. VA]

In my experience......

Your best to keep the major parts that came originally on your vehicle and just have them rebuilt. It helps to keep things in order and correct...as in the head on the engine, the transmission, things like that. In other words, don't just swap a mass rebuilt head. Who knows where it came from and off what. Is just that in my experience it helps to keep things correct. (did any of this make sense?)