1992 LT1

[jmoseley]

I have a minor leak from the cylinder heads.  Is it feasible to re-tension the heads to stop the leak or am I faced with more drastic action if I can't ignore the leak.
Also does anyone know how to drain the oil from the diff - there does not seem to be a drain plug?

[Scott]

A re-tension of the bolts won't cut it.  You'll probably need a new headgasket.  If you keep driving and let it get worse it may cause more damage.

On my C3 is looks like you have to pull the rear cover to get the oil out or use a pump to suck it out.  Yours may be the same.

[jmoseley]

The oil leak from the heads is just a trace at this stage - there is no significant oil loss and no telltale drops on the garage floor.  Just wondering whether I should go to the expense of pulling off the heads at this stage

The C4 diff must be the same as the C3 but surely GM didn't intend for the oil never to be changed

[Scott]

Sorry, when I heard a minor leak from the head, I was thinking compression leak.  You can try re-tensioning the head.  Where is the oil actually leaking from?
How much oil is leaking?  If you degrease the engine, how long until the leak is visible again?

[87Z51]

The oil leak from the heads is just a trace at this stage  

Is the leak from the heads or the rocker cover? There are not many places oil can leak from the heads themselves
Where on the block is the oil?

Have to use pump to get oil out of diff unless you crack the diffhead loose