18 replies to this topic

[bpirie1000]

Can not see how it would be oil comming out the spark plug..

It should only be petrol in ...... Gas out...

Never any oil in the chamber that could come out the spark plug under the washer.

New plugs all round and look at the threads whilst you are at it.. maybe even get a boreoscope to insert look at the chamber walls.

The head could not be hairline cracked, could it.....maybe some engineers blu wiped along the head whilst head is hot...

[DClarke1954]

Spark plugs are positioned to sit with the sparking end inside the combustion cylinder - that's how they ignite the air/fuel mixture and how the engine turns over. The only way you would have oil originating from the spark plug hole itself would be if it is blowing past the piston rings, into the combustion chamber and out of the opening. If that were the case you would absolutely know, as it would be running rough as anything and coughing blue smoke.

I would be very willing to bet it's from the rocker cover gasket, and that's arguably the easiest and cheapest repair you're going to get on a mini!

I know you've said you've tested for it, but if you've only taped paper at one end and the other and then driven, I reckon your paper has flapped about a bit and perhaps missed a drippy leak

 

 

No it taped both ends AND placed a wad of paper between the plug and the paper to force it to sit on the block.
When I took it off BOTH the test strip and the wad of paper were clean.  This is why it's a puzzle.
I can change the gasket no problem, ATM I have swapped the plugs over to try to confirm its block position (gasket) or plug itself.
Thanks for your help. 

Edited by DClarke1954, 10 June 2025 - 05:45 PM.

[Earwax]

My best bet is soaked rocker gasket and the leak maybe from around the back   But it certainly seems baffling.

 

You might also just rule out the dipstick hole as a possibility

[DClarke1954]

Time to "fess-up".

I appears that it was indeed a weep/leak from the rocker-box gasket.  So thanks to all that pointed at it.

A "tell-tale" taped to the block did not show the leak BUT...  I decided to swap plugs 3 & 2 and at the same time I gave the T-bar nut on the LH side of the rocker box cover another 1/4 turn.

I packed a wad of kitchen towel between the #3 plug and the block to check for a leak and no leak, not a drop, trace or anything.  No oil in plug well's 3 or 2 so it clearly wasn't a plug issue (as you all had said).
So, one in the eye for me, and thanks to y'all.