W212 E250 oil in coolant

[Blazer2904]

I had a long journey on Sat so I placed a hand towel over the expansion tank cap & around it to soak up any coolant spillage. I drove 200km mostly motorway at 100-120 km/hr. When I stopped I checked the towel & it was bone dry & there was no sign of any coolant leak from the cap. I drove 240km the next day again with no leaks. Has anyone any idea as to why it didn't leak? It had leaked on 3-4 previous journeys of 50-80km.

 

[BlackC55]

Check your oil filler and see if there is any milky sludge, if so head gasket is probably gone.

Water in oil is very rare on a MB engine. Oil in water is much mor ecommon.

If its pressurised I would do a "sniffer" test first. Then if it fails that, head needs to come off.

 

[Blazer2904]

Water in oil is very rare on a MB engine. Oil in water is much mor ecommon.

If its pressurised I would do a "sniffer" test first. Then if it fails that, head needs to come

 

[Blazer2904]

No longer oil in coolant or vice versa. No loss of power. Only coolant loss through the expansion cap on long journeys but seems to have stopped. I've replaced the expansion tank, radiator, auxiliary motor & then another new cap in the last few months . Don't think it's the head. Car has done 12 k miles since Feb . It's doing 48mpg average.