wardycatt 7 Posted May 9, 2013 Report Share Posted May 9, 2013 I removed spark plug number 6 from my car the other day, and it's covered in oil. I noticed some splashes of oil on the inside of the metal HT lead cover. The top half of the ceramic end of the plug was clean, the hexagonal 'nut' is totally black and oily and the thread is oily as well. The electrode is slightly black and appears to have a moderate amount of carbonated oil residue on it. So I have two quick questions. Firstly, is the oil likely to have come from inside the engine (as opposed to an external leak which has pooled into the number 6 spark plug hole)? Secondly, what are the most likely culprits (internal and external)?I can't see anything obviously leaking components, so I'll probably end up taking the head off at some point in a bid to get to the root cause. But if anyone has some info before I get involved with that, it would be much appreciated. Link to post Share on other sites
spadam 7 Posted May 9, 2013 Report Share Posted May 9, 2013 Oil in cylinder could possibly be valve stem seals or piston rings.Oil from external could be a number of things Link to post Share on other sites
Woodyman84 3 Posted May 9, 2013 Report Share Posted May 9, 2013 if there was oil internally wouldnt you see some sort of sign of it through the exhaust? Link to post Share on other sites
spadam 7 Posted May 9, 2013 Report Share Posted May 9, 2013 Yes usually blueish smoke Link to post Share on other sites
wardycatt 7 Posted May 9, 2013 Author Report Share Posted May 9, 2013 I've not noticed any smoke. It's been running rough, but the plug replacement seems to have dealt with that. I'll need to look into it in more depth. Link to post Share on other sites
CALICO 130 Posted May 10, 2013 Report Share Posted May 10, 2013 Its a bit difficult to get oil leaking as far up as the ht lead without a crack in the head so maybe oil was spilt when topping up. Link to post Share on other sites
Lukey. 381 Posted May 10, 2013 Report Share Posted May 10, 2013 It will have come from the cam cover gasket Link to post Share on other sites
Daverse 175 Posted May 10, 2013 Report Share Posted May 10, 2013 If its coming from the outside I'd say rocker cover gasket Link to post Share on other sites
VR6Pete 1,455 Posted May 10, 2013 Report Share Posted May 10, 2013 Yeah. Fairly common issue. Link to post Share on other sites
wardycatt 7 Posted May 13, 2013 Author Report Share Posted May 13, 2013 Cheers guys, I've yet to take the inlet manifold off for a proper look, but I think you're correct. New gasket is on the way. Link to post Share on other sites
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