View single post by Mark Rosenbaum
 Posted: 01-10-2007 01:46 am
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Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
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I've listed some possible causes, and my opinion as to how likely each one is, below.  There may be others that escape me at the moment.

Defective o-ring on the spigot part of the distributor casting.  Very common.  Here the fix is to replace the o-ring.  The part is less than a dollar, but removing the distributor, replacing the o-ring, reinstalling the distributor, and re-timing the ignition, is a bit tedious.

Leak from the intake cam cover.  Common.  Usually the fix is to degrease everything then correctly install the cam cover gasket and tighten its hardware precisely to spec.

Leak from oil filter or oil cooler adapter casting.  Uncommon.  The filter may be loose or have a bad gasket, or the gasket between the adapter casting and engine may be bad.  The latter gasket is available if necessary.

Defective distributor internal oil seal.  Uncommon.  Here the part is only a couple of bucks but one has to completely disassemble the distributor to replace it.

Bad gasket for the casting that mounts the fitting for the oil gauge pipe, or a bad or loose fitting or pipe.  Uncommon.  Parts are available and not too expensive.

Leak from main oil gallery sealing plug.  Rare.  The fix is to remove the plug, apply new sealant, and reinstall the plug.  Will require a special allen wrench or equivalent but otherwise a quick repair.

Leak between cylinder head and cam carrier casting.  Rare.  The repair involves pulling the cam carrier -- considerable work and moderate expense.  There are a couple of possible minor pitfalls and a novice mechanic might find this task to be a bit of a reach. 

Leak between engine block and cylinder head.  Very rare.  This is major and requires pulling the head -- lots of work, lots of money, and several potential problem areas that might each add days and hundreds of dollars to the cost.