Oil Stain

is200 Newbie · February 18, 2017

Was in the engine bay today giving it a clean - I was going to give the seals a good clean also but waiting for the "gunk" to do that which has not arrived yet so will do that next week.

I took the main cover off to check the pipes and bits over and found a wet oil stain on one of the pipes - circled in the picture below ... (or what looks like oil)

There's no indication as to where this has come from - it looks like a oil breather pipe. Everywhere in the bay is dry - the larger pipe that the breather goes into is dry - I cant find any sign of oil anywhere else. This breather pipe however is not in its recess properly - must have been like that since I have had the car or worked loose some how as I have not taken it out at any point.

Cleaned the pipe and the connecting plug and put it back together correctly - was very hard to seat back in correctly and I had to lube up the connecting plug to get it in and even that took some doing so cant see how if could have worked loose.

Anyway - will keep an eye on it to see if the oil comes back ... anything I should be looking at to find the source?

Verbout · February 18, 2017

Is it the breather pipe from the rocker cover at the top of the engine?

Quite normal.

Fumes, including oil fumes, are scavenged from the top of the engine and burnt via the corrugated pipe (air inlet) you see in your picture.

is200 Newbie · February 22, 2017

I have ran this for almost a week now after re-securing the plug into the air pipe as in the pictures above

What issues could be faced from this not being connected properly - I presume hot air (fumes etc) would be sucked into the carb and burned off so am presuming heat would be the main factor missing before I re-connected it. It was obvious it was leaking before.

This week after re-connecting the plug into the pipe the car has driven a bit better in the way it pulls away at junctions. Would this re-connection have been a possible cause of the improvement?

Verbout · February 22, 2017

No issues, just an oily patch on your pipe work.

Some breather pipes have a one way valve so the hot gas goes into the intake, and the metered air goes where it's supposed to, into the throttle body, no carbs. ;)

With your loose pipe the metered air may have been escaping causing issues with fuel metering.

After the fix the car will have sorted itself out.