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Hi all, I have a 2003 1.8 estate that's done 135,000 miles. Just noticed mayonnaise on the dipstick - but there isn't any under the oil filler cap (yet???) and the coolant level doesn't seem to have dropped. I did an oil change 100 miles ago, but the car mostly does short journeys. Any chance it's not the head gasket, but maybe a venting problem? What do you think I should check first? I'd be grateful for any reassurance! Thanks, Nick

Could simply be condensation, which does happen on lots of short journeys - mayonnaise isn't always a head gasket diagnosis.
You can have a 'sniff test' done on the car - it's simply a reading done from the expansion tank.

nickrose137 wrote: ↑Sat Jan 06, 2018 7:03 pm ...the car mostly does short journeys.

Seconded on the condensation. Although I've only ever seen it on the filler cap (on ancient Hillmans). Might be worth just taking it on a decent journey.

Mayonnaise on the dipstick can only really come from water mixed with the oil in the sump. If it's serious the oil will no longer protect the engine.
I had this on a Lotus Europa, caused by a badly fitted water pump during an engine rebuild. I started it up and noticed the oil pressure falter, then disappear. Dipstick was pure white.

If it was me, I'd drain the sump and see if you've got mostly oil, (in which case refill with fresh oil & monitor), or if there's a lot of water find the reason & rectify before you wreck the bottom end.

Hope I'm wrong and it's OK

Try giving a long run and get it really hot, if the mayonnaise then dispersal its probably just the result of the engine never getting hot enough, if it doesn't probably needs further investigation.

Peter

Thank you all for your replies. After another oil and filter change, and a 400-mile round trip, there are still traces of sludge on the dipstick, so I'm not optimistic. I'll try and get her through the MoT at minimal cost next month, and start looking for a replacement. I'll miss her, because everything else works

2000 miles and 1 new MoT later the mayo has not returned. Maybe the K-Seal did the trick, or maybe it was just the longer journeys and healthier running, but all is well for now...