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kenward1000

240z head gasket replacement

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My 72 is leaking increasing amounts of oil, at the upper edge of the engine front cover, where it meets the front edge of the head.  Looks like the head gasket is mangled there.  No coolant seen.

Trying to get a sense of how big this job is, any special tools required, anything that should be inspected after the removal, parts that should be replaced as a matter of course, the whole enchilada.

Have all the normal automotive tools and mechanical ability.

Searched YouBoob and the forums for threads about prepping for/accomplishing this task, didn't find enough.

Thanks for reading this post!

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Food for thought, if you would rather avoid removing the head.  That area should be an unpressurized area, it only sees oil that drips down from the valve and timing chain sprocket area.  So, you could probably reseal it from the outside without removing anything.  Clean it up well, maybe dig out the old gasket, spray it with some cleaner.  Then put some RTV on the gap and work it in to create a new gasket.

Just a thought.

There should be a bunch on the site about head removal and replacement.  Try words like "shaved head", engine rebuild, rocker arms, cam replacement, etc.  

Can't really guess on "while you're there" stuff unless the condition of the engine is known.  Timing chain, for example, might be worth doing.   Valve guides, why not?  Once you get the head off you'll want to measure flatness.  Might need a skim.  Then maybe some head saver shims.  You'll probably break a head bolt, of course.  Might as well resurface the exhaust manifold, it probably needs it.  And you'll probably break an exhaust manifold bolt or two.  But it'll all be fun.

Edited by Zed Head

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Maybe you can take off the front cover without taking the head off..  there are some spots were oilpressure is on it..  put in some new (selfmade of paper) gaskets.

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you can def take off the front cover without removing the head. IF the head gasket is really mangled around that area, and if that is the cause for the leak, as ZH mentioned you could maybe fix form the outside, OR remove the front cover and see what can be done to the part of the head gasket that seals the front cover to the head. This would let you get some sealant to replace the damaged area. It would be a good while you are in there time to check the timing chain and guides for replacement esp the tight side guide. If its got deep gouges where the chain run, replace it before it breaks.

There is both water and oil galleys inside the front cover to the engine block that needs to be water and oil tight. A good gasket and careful application of a sealer esp around those areas would be a good idea.

loosen the oil pan and drop the front edge down about 1/8th inch min in addition to removing all the bolts (don't forget the two top ones that bolt the head to the cover). You will need to get the rad out, the damper, and IF you have AC maybe the AC mount (I did on the low mount compressor), and the fan to get access. Not a hard job but if you break a bolt then it could be a long day.

Use proper technique on bolt removal if they seem stuck. I use heat/shock/tighten then loosen, what ever works for you.

considering all the above, I would second ZH recommendation about trying an external fix, unless you KNOW the TC guide is an issue. Mine broke on a long drive so I am very focused on that one thing.

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I'm dealing with some DPO hack.  Looks like they had the front cover off, then mangled the head gasket when trying to slip it back in place.  There are two small fasteners at the lower front of the head.  The driver side one is missing but can't be replaced because the head/head gasket/front cover holes don't line up.  

Did some cleaning then external sealing today.  If that doesn't work then it seems like the head has to come off, to replace the mangled head gasket and the mis-aligned fastener holes.

Thanks for the tips!

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