Hi,

Whilst looking at another problem with my 1.2 fabia I noticed some oil pooling around the spark plug on cylinder number 1 (I think it's number one. Far right one as looking at engine). I started the engine and noticed oil bubbling up from the spark plug. I assume this is not a good sign but can anyone give me an idea what's going on and how to sort it?

So I've had a look at this. Found that the spark plug in question was quite loose when removing it. Literally zero resistance when unscrewing it. I'm sure it was tight when I replaced them in March. There was loads of oil and crap in the hole so I've cleared it out as best I can and put a new plug in. It's tight in now so hopefully that's sorted it. I ran a compression test and all 3 cylinders are between 15.5 and 16.2 bar with the oiled up cylinder being the lower reading. Fingers crossed else I'm going to lose my sense of humor. I've never loved and hated a car so much!

The compression test is "okay", at least based on the usual rule of thumb that all cylinders should be within 10% (say 1.5bar and your figures say they're within 5% of each other).

 

I've seen cases like you describe where the plugs descend through the rocker cover into the head, but don't know if that applies to this engine?

Did you torque the plugs properly ???

 

"I'm sure it was tight"....christ that sounds vague to me. Like "I'm sure I turned the oven off or turned the tap off, before leaving the house"

 

There is only one sure way to be sure, do it properly, torque them properly.

I just did them on an O3 ( because the dealer didn't ever), and trust me, its not something I'd ever want to get wrong.

 

The torque was per the servicing manual to the letter. But I bet you will be more sure this time !

Edited 7 October, 20169 yr by vRSAnt

You must be the first person ever to under tighten a spark plug.

Is this the 12-valve variant? If so this could be an oil leak from the cam-carrier to head seal (as Ken suggests), possibly exacerbated by breather blockage. Keep an eye on it for a few weeks to see if the oil returns.  Also try loosening the oil filler cap while the engine is running and see if it tends to get sucked back down, or blown further off, to investigate the crankcase pressure and breather system condition.

 

Ignore that above. Yours must be 6-valve as you can't see the place where you saw oil bubbling with engine running on the 12-valve.

Your engine looks like this, right?

 

 

Cylinder 1 is (RHD) driver's side, so I think you mean cylinder 3.

Edited 7 October, 20169 yr by Wino

Thanks for the help / type of telling off my wife gives me! Ha ha

I did use a torque wrench first time round, 30nm all round (or so I thought). Would using an extension bar on the wrench affect it much?

It is possible I missed one I suppose but there is only 3 of them so not much to remember.

Wino, that's the engine so cylinder 3 is the culprit. It seems OK now so far. Ill keep an eye on it and check the plugs in a week or so. Hopefully they don't unscrew themselves.

Thanks again.

Extension shouldn't have made any difference.

 

You did say that the area was mucky; perhaps you got a bit of grit trapped between the plug sealing washer and the head surface that it tightens against. At the time you torqued it up correctly, but then this piece of grit gradually embedded itself in the aluminium of the head, reducing the tightness as it went?