missfire on startup

[parakeats]

So, recently, my 1990 318i has been miss-firing on startup (not everytime) it lasts a short while or until revved through a little bit. It absolutely stinks of oil, massively more so than it usually did. I had a quite glance at the oil cap and it didn't look as good as last week, greyish rather than black - will try and get a picture later on.

I've recently had to put some more water in but only from 1/4 of radiator to the fill line when cold so not massive amounts - might help with suggestions in some way?

Any ideas what to check next? It's my daily driver so ideally I don't want it off the road

[parakeats]

oh, and the temp gauge sits between 1/4 and middle, but was high in traffic the other week, over 3/4 and towards the red, but it came back to normal once i got moving again - my viscous fan coupling doesn't work

[Brianmoooore]

Has the symptoms of a partial head gasket failure (less likely - a cracked head), which would fit in with the overheating.
A small amount of coolant is seeping into one cylinder when the engine is stopped, wetting the spark plug, and stopping it sparking until the water is expelled by the running engine.
Remove all the spark plugs and check the colour of their tips. If one is cleaner than the others, then this will support the theory above. Crank the engine with the plugs out, while watching the plug holes. You might see a little water being blown out from the affected bore.

[parakeats]

I was suspecting that too, old car had a similar problem and eventually turned into a full on kettle...

I'll give that a go, finish work early today so i've got time this evening. Should I leave it a while so it cools down before cranking it over with the plugs removed, or would it not make a huge difference? And do i need to disable my fueling system so i'm not just spraying fuel out the plug holes?

[Brianmoooore]

Ideally you should be checking when the car has stood overnight - that's when the problem occurs. Any water in there will be expelled at the first turn of the crankshaft, so you only do it for a second.
If you crank from the diagnostic socket (short pins 11 and 14) with the ignition off, then the fuel injectors will be disabled.

[parakeats]

Okay thanks, I'll see if I have time for that tomorrow.

I was unaware you could crank form the diagnostic socket - always handy for time like this I s'pose!

Would you recommend not driving the car as it is currently? I have a 200 mile trip to do this weekend and don't really fancy breaking down on the M4 or damaging my engine with possibly some water in the oil

[parakeats]

took the plugs out, this is how they look - pretty much dead on, the left one looks a little white though?

done about 14k miles on them