Monday, 17 October 2011

1998 jeep cherokee 4.0 head gasket?

Hey I want to change my head gasket and get the head resurfaced and everything but everyone keeps telling me that its too much of a job to do myself. It doesn't seem like it would really be that bad though. Does anyone know where I can get step by step instructions for this just in case I forget where something goes though? Or if somebody can give me some directions it would be appreciated. Thanks.1998 jeep cherokee 4.0 head gasket?well for step by step the closest thing you can get to that is a chiltons/haynes manual, but its just like any other you have to remove the manifolds and fuel system. it can be quite a job depending on the room and everything over the head in question, most jeeps are at least 6 bangers so you might consider replacing both if your doing it for any other reason than one side needing it. just start removing things and mark every set of bolts to insure they go back where they need too. you will ahve to depressurize the fuel system and there should be a valve along the fuel rail to do this. of course unhook the battery. when removing things like the manifold you want to alternate the bolts when you remove them as you would lugnuts. so you dont warp it when removing or replacing. try to mark all the wires too, best way is to use masking tape and put an indicator like 'a' on the wire and 'a' on the other end of the connector that it attaches to. you do not have to disassemble everything so try to keep it together if possible. in other words you dont have to open the throttle body up just remove the whole thing from the base. then remove the manifold and most likely some sub systems like the alternator spark wires ,etc to get to the head in question. also if you have multiport injectors remove all the bolts fastening it to manifold and once loose the injectors will pop out will a little pull as they are just pushed in and sealed with o rings

then remove the exhaust manifold bolts but dont remove the whole thing unless you have too. now when you get to the head its even more important here that you remove the bolts in an alternating fashion. say you have 10 head bolts and we number them from left to right from top to bottom. then break loose first number 3 then 9 then 4 then 7 then 2 etc and of course break loose all before you loosen anymore. and cut a piece of cardboard out and label it and put holes in it to match the headbolt layout, as you remove a bolt put it in the right spot in the cardboard, this way you know where the longer bolts go in case they are not the same size. and do this even if your getting new bolts

just use your common sense and mark everything since you lack experience this will truly benefit you as it could be a week before you put it back together. now if the head needs to be trued and pressure tested you should cover the cylinders with non fibrous cloth and coat them with a light covering of oil to help prevent rust build up. and while you wait start preparing all surfaces for the new seals. use a putty knife and keep the knife just above parallel with the surface as you dont want any knicks or scratches in the matting surface or you have leaks. and try not to get any old gasket in any ports on the block

now when you go to replace it of course you will need all new gaskets and you really should get new head bolts too, and at the very least use a torque wrench for the head bolts and really again since you lack experience you should use the torque wrench for the manifolds too. you can get the torque requirements from the chiltons/haynes manual which you should invest 10-20$ in for this job.

also coat the head bolts with oil before you put them in which helps in antiseizing.

now for any rubber gaskets and orings make sure you coat them with oil, and for paper gaskets a thin layer of permatex is good unless the manual tells you otherwise. and when you get to the injectors if multiport you have to make sure they pop in correctly as it wont ake too much force but you have to make sure they seat correctly. now when its all back together make sure you turn the ignition on several times before you try to start, this allows for the fuel pump to repressurized the system. and you really should have someone else do this while you inspect under the hood for any fuel leaks before you actually start it. now this is a sloppy layout for the answer but it should get you going
1998 jeep cherokee 4.0 head gasket?
If you're handy with taking stuff apart on your jeep, it will be very easy until you remove the head. From there of course just let a shop rework the head, then bring it home and toss on the highest quality gasket you can find and torque to factory spec. As others have said, a manual will help you greatly. Remember now is the time to consider any other maintenance/cleaning and upgrades you may want to do while the parts are out. Don't get discouraged by people telling you it's a huge job. The 4.0 is one of the easiest engines to work on and everything is very accessible. Just take your time and be careful to do things right.

P.s. Port and polish? :D
1998 jeep cherokee 4.0 head gasket?
If you are handy (mechanically) with vehicles I'd say go for it. If you are not real handy I'd say don't attempt it. This will require a good selection of handtools and a service manual from Mitchel or Chiltons. This will also require a torque wrench, gasket scraper and other specialized tools. You can take digital photos as you do the disassembly and put parts in marked plastic baggies. This will assist you in reassembly and keep parts from being lost. This is a pretty big job and I would guess that since you asked the question here you probably shouldn't do it (no offense intended).

Hope this helps in your decision.

It's not too big of a job. Get a Chilton manual for reference, and allow enough time to get it done.

Heres a tip; take a few %26quot;before%26quot; pictures, and take a few more during the disassembly process.

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