Advice on an odd problem - am I worrying over nothing?
Discussion
I've posted every now again in this sub asking for advice from people much more experienced than me, because I've been concerned about something, only to discover that I'd been worrying over nothing and everything related to my post went according to plan. I'm hoping this time will be the same 
I'm getting a rather odd problem, which I can't seem to find an answer to. I removed the spark plugs on my engine a year or so ago during a service. They weren't due for replacement, but I thought I'd check them to ascertain the health of the engine - all was well. However, since then, one spark plug has been getting its insulator saturated with oil. As far as I can see, the spark plug tube seals are fine.
Is there any way I cross-threaded the plug, thereby allowing oil to come from somewhere it shouldn't due to a poor seal? It's worth mentioning that I've removed and reinstalled said plug since, and it came out and back in again with no issues. The engine also runs fine. I just can't think of any other reason as to why oil started leaking into the plug well only once I removed & reinstalled the plug, so, naturally, I'm worrying!
They're due for replacement in Jan so I'd like to know what I'm up against! Thank you
I'm getting a rather odd problem, which I can't seem to find an answer to. I removed the spark plugs on my engine a year or so ago during a service. They weren't due for replacement, but I thought I'd check them to ascertain the health of the engine - all was well. However, since then, one spark plug has been getting its insulator saturated with oil. As far as I can see, the spark plug tube seals are fine.
Is there any way I cross-threaded the plug, thereby allowing oil to come from somewhere it shouldn't due to a poor seal? It's worth mentioning that I've removed and reinstalled said plug since, and it came out and back in again with no issues. The engine also runs fine. I just can't think of any other reason as to why oil started leaking into the plug well only once I removed & reinstalled the plug, so, naturally, I'm worrying!
They're due for replacement in Jan so I'd like to know what I'm up against! Thank you
paintman said:
What car & what engine?
No obvious oil leaks?
You've thoroughly cleaned the surrounding area so that any would show up?
You've tried swapping that plug with one from another position?
I have recently cured a rocker-cover oil leak by replacing the gasket. I can confirm that the leak is fixed although the engine does still lose a small amount of oil, possibly from a blocked crankcase breather which is common on this model of car (also a small amount of oil in the air filter housing).No obvious oil leaks?
You've thoroughly cleaned the surrounding area so that any would show up?
You've tried swapping that plug with one from another position?
The car is a Clio, with the 1.2 D4F engine. Cheers for the reply
HazzaCrawf said:
paintman said:
What car & what engine?
No obvious oil leaks?
You've thoroughly cleaned the surrounding area so that any would show up?
You've tried swapping that plug with one from another position?
I have recently cured a rocker-cover oil leak by replacing the gasket. I can confirm that the leak is fixed although the engine does still lose a small amount of oil, possibly from a blocked crankcase breather which is common on this model of car (also a small amount of oil in the air filter housing).No obvious oil leaks?
You've thoroughly cleaned the surrounding area so that any would show up?
You've tried swapping that plug with one from another position?
The car is a Clio, with the 1.2 D4F engine. Cheers for the reply
Megaflow said:
There’s your answer. The rocker cover gasket will seal around the spark plug bore as well as the outside of the engine. The gasket around that spark plug must be damaged and leaking.
Thanks a lot - so it's not possible for a cross threaded plug to cause the wells to fill with oil? I suddenly feel happier now!
HazzaCrawf said:
Thanks a lot - so it's not possible for a cross threaded plug to cause the wells to fill with oil?
The plug just goes from outside into the combustion chamber.It's entirely possible to cross-thread one, but it won't leak oil - if anything leaks, it'll be exhaust gases.
Dogwatch said:
As above. The oil is coming from outside, nothing to do with the plug fitting or function.
Sorry, the oil leak ain't fixed yet!
Haha it seems so. I'll replace the plug seals once my university exams are over at the end of JanSorry, the oil leak ain't fixed yet!
I did consider the possibility of an oil leak via those seals (which I didn't replace, only the gasket round the edge of the rocker cover/head interface, and the leak there has been fixed) but my mind jumped to the worst conclusion - that being a damaged plug
ah well - cheers guys
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