Engine Mayo

[Alfie 6]

I know this must have been covered before, but can anyone tell me why after an oil and filter change and daily 22 mile runs to work, there is so much mayo in the oil filler?

[Anthony 1,003]

You get alot of mayo because the breather system design isn't very good IMO.

 

Basically, in winter the air is cold and damp, and mixes with the oil vapour and oil deposits in the breathers to make mayo. Unfortuntately, unless you're regularly getting the oil hot enough to "burn off" the deposits, it just builds up and builds up until such time as you remove the filler cap and wonder who emptied a jar of Hellmans into your filler tower and pipes.

[Alfie 6]

You get alot of mayo because the breather system design isn't very good IMO.

 

Basically, in winter the air is cold and damp, and mixes with the oil vapour and oil deposits in the breathers to make mayo. Unfortuntately, unless you're regularly getting the oil hot enough to "burn off" the deposits, it just builds up and builds up until such time as you remove the filler cap and wonder who emptied a jar of Hellmans into your filler tower and pipes.

No answer to this then Anthony? must have scared the pants off the people that bought them from new!! I don't want to thrash the living day-lights out of it just to get the oil "hot", can't afford the fuel for a start. I assume it does no harm and to just disregard then?

[GLPoomobile 958]

There's obviously the possibility of a failing head gasket too. I wouldn't of course automatically assume the worst from a bit of mayo, and there's no point in scaremongering, but equally you have to bare in mind that it is one of the symptoms and shouldn't be ignored.

 

Check a few other things (all been discussed before) just for peace of mind.

[gaz832 7 1 Cars]

mine does this at times, just give it a good thrashing to remove the gunk lol

[Alfie 6]

There's obviously the possibility of a failing head gasket too. I wouldn't of course automatically assume the worst from a bit of mayo, and there's no point in scaremongering, but equally you have to bare in mind that it is one of the symptoms and shouldn't be ignored.

 

Check a few other things (all been discussed before) just for peace of mind.

Yes, suspected a H/G a couple of weeks ago oddly enough. I have done a compression test and all cylinders showed 14 bar (200psi) I've put a new rad'cap on and no visible signs of oil on the coolant, but it does loose a little, say half pint over 2-3 weeks maybe less. Other usual Pug stuff, electrics etc, but no other issues. The 10 mile trip to work is dual carriageway at 65-70, but oil temp' never very high anyway.

[GLPoomobile 958]

Ref oil temp, even without an oil cooler, you need to be going some to get the temps up. Sustained high revs will get the temps up, but normal motorwat cruising won't see it much about the first mark on the gauge.

[JRL 14 1 Cars]

check the oil breather hoses have perished to the point where there is small holes. I have recently replaced them with silicone as mine were very perished and starting to split this helped al ot but has not cured it.