misfire..... oil???

[peter_cupra197]

just wondered if anyone could help, my cupra developed a missfire under full load around 4k upwards, so gave it a full service today upon removing the plugs cylinder 4 was swimming in oil? now i replaced the plugs the missfire is even worse? any help much appreciated.

 

[plattsy]

Coilpack is the engine management light on ??

 

[Slimy]

+1, I'd also suggest coilpack 4 isn't doing it's job. Bear in mind that a coilpack can become troublesome before the light comes on, but it usually isn't far behind.

 

[peter_cupra197]

management light came on the other day i plugged in to a friends snap on reader but only lists as "multiple misfire" i cant get to vag com untill this saturday coming when i looked at the plugs they were eally crappy so thought to change them anyway (being the chepest option first) but doesnt explain why the plug hole was filled with oil

 

[Slimy]

Things can go very peculiar when a piston is just moving with the other three rather than having the proper explosive force pushing it down. I wouldn't be surprised if you are getting a tiny amount of oil in there because it's not behaving itself.

Alternatively, there could be a gasket failure that is letting oil leak, which in turn is killing the coilpack.

 

[plattsy]

IDE deffo say coilpack failure mine usually start when it holds back on boost and then it starts having a hissy fit and decides it wants to sound Like a scooby but for good measure put some new plugs in aswell

 

[peter_cupra197]

ok thanks for advice wil order some coil packs tomorow

 

[AlexGSi2000]

Isn't the rocker cover gasket usually the culprit when sparkplug wells start filling with oil?

 

[peter_cupra197]

I thought this so ordered one for good measure

 

[Slimy]

Isn't the rocker cover gasket usually the culprit when sparkplug wells start filling with oil?

Bingo, that's the one! I did have a nagging thought in the back of my head that there was another reason for oil.

 

[peter_cupra197]

all sorted misfire was coilpacs and i will do the gasket on sunday ad post results

 

[Big_daddy]

Can oil seep through spark plug into the cylinder? if the rocker cover gasket is leaking....

 

[AlexGSi2000]

Can oil seep through spark plug into the cylinder? if the rocker cover gasket is leaking....

I should think with the threads on the spark-plug - tightened to the right amount, no oil should seep through at all.

 

[smiffymk3]

Isn't the rocker cover gasket usually the culprit when sparkplug wells start filling with oil?

+1, happens a lot