Mayonnaise on dipstick

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Mayonnaise on dipstick

Post by nickrose137 » Sat Jan 06, 2018 8:03 pm

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

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Re: Mayonnaise on dipstick

Post by GingerMagic » Sat Jan 06, 2018 9:28 pm

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.
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Re: Mayonnaise on dipstick

Post by steve_earwig » Sat Jan 06, 2018 9:50 pm

nickrose137 wrote:
Sat Jan 06, 2018 8:03 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.
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Re: Mayonnaise on dipstick

Post by Doggy » Sat Jan 06, 2018 10:50 pm

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
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Re: Mayonnaise on dipstick

Post by PeterN » Sun Jan 07, 2018 11:51 am

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.


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