Very slight white residue....!

[merc180k]

Hi folks,
Got a warning to fill up with 1 litre of oil at next refuel tonight on way home on the motorway, so duly did so when I got home.

When I took the filler cap off to add the oil there was a very slight white residue on the underside of the fillercap and around the outside of the thread - don't get me wrong we are not talking massive amounts like you'd expect from lots of water in the oil (in fact the actual inside of the hole is black - no white anywere, just the cap). In comparison I'd say about half a fingernail width if not slightly more.

Could this just be from moisture sitting in the outide of the thread of the cap? How can I check if it is the start of anything more serious before it really hits??

Cheers,
Simon

 

[Will]

Aside from the mentioned motorway trip (how far/long btw?) have you been using the car for lots of short/local journies?

If so it may just be a build up of condensation and without regular long runs to fully warm the engine up they haven't had a chance to heat up and boil off.

If the coolant is clean and hasn't been dropping, and the oil is otherwise free of contamination I wouldn't be worried

Will

 

[BlackC55]

Don't worry. It is perfectly normal

 

[merc180k]

Aside from the mentioned motorway trip (how far/long btw?) have you been using the car for lots of short/local journies?

If so it may just be a build up of condensation and without regular long runs to fully warm the engine up they haven't had a chance to heat up and boil off.

If the coolant is clean and hasn't been dropping, and the oil is otherwise free of contamination I wouldn't be worried

Will

I do about 30 miles (max round trip) a day with this being mostly 10-20 mins on the motorway each way. So maybe this is normal then? Due a b service in 2400 miles (ish).

Thanks.