What could cause mayonaise under oil filler cap?

As I understand it's a common symptom of cars that are not properly warmed up. It's condensation forming inside the oil.

Reply to
DervMan
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When I first viewed Mrs S's prospective purchase, a 98 R Hyundai Accent Coupe, it had great dollops of mayonaise under the oil filler cap, so paid special attention to all the other signs of HGF, but found nothing else. I still bought the car after negotiating a suitable discount off the already favourable price ( paid £650 with 13 months MOT & 2 months tax ) however , so far, no HGF problems have materialised.

I vaguely remember owning a car years ago with similar symptons, but no other problems, and assumed it was a characteristic of that car ( can't now remember what model ) but could anyone come up with any other cause for mayonaise apart from HGF. I've checked that the breather tube to the throttle body is clear and according to heater and temperature gauge the thermostat is functioning well. As yet I have not changed the oil, obviously this could be the next step, however it looks very fresh

Reply to
Steptoe

Take it for a belting run to get it thoroughly warmed up and hopefully evaporate some of the water out of the oil. If this doesn't cure it, change the oil. But the best treatment for engines is to run them hard. Keeps them nice and warm. Too much soft pedal is bad for them

Rob Graham

Reply to
Rob graham

A friend had a 95 Fiesta 1.1 which produced mayonnaise in the winter, but it always went away with the warmer weather. She did lots of short journeys and low mileage. I used to change the oil every 6 months for her and this seemed to keep it at bay. Some oils were better, and I seem to recall Duckhams being better, but it was a few years ago now. At the spring oil change I always cleaned the oil filler cap and breather out with carb cleaner.

Reply to
Doctor D

Yes, even air-cooled VWs would do this if used for short trips. As a young bloke with my first beetle, I was once told by a garage that I had a leaking head gasket when they took off the oil filler cap.

John

Reply to
John Henderson

Thanks for all replies, the consensus seems to be that the engine hasn't warmed up properly. Interestingly enough the previous lady driver only travelled about 4 or 5 miles to work, and didn't seem the type to put her foot down, Mrs S will no doubt shortly administer the antidote to this situation.

We owned a 90 Fiesta 1.1 at one stage, maybe this was the other mayonnaised example I was trying to remember

Reply to
Steptoe

Had this with my first car, an F reg 1.0 Fiesta. As I was only driving 5 miles to work (max) and back again during very early and very late hours the temp gauge was barely rising off the bottom in cold weather and mayo under the cap. I got around it in the end by covering half the radiator wit tn foil to deflect the air. Cured all, but some trial and observation required to balance the amount of rad to be covered against where the temp gauge should be. Also needs to be easily removable in case of a major traffic jam.

PDH

Reply to
Paul Hubbard

Shouldn't the thermostat not let any water through the radiator until the engine is warm enough anyway? Surely in this case the foil would make no difference?

Tony

Reply to
Tony Brett

Cold air across the rocker cover in the winter, combined with a slight design fault if the highest point of the engine has no ventilation to it. You get condensation and hey presto, you're there.

My 1.6 Astra does it in the winter (clean it off every week to stopit building up) but not the summer.

Neither of my previous VX's did it (1.8 Cav, 1.3 Cav) - As I recollect they had alloy rocker/cam covers, with a ventilation point (hose leading to inlet) bolted to the top, higher than the filler cap which itself was metal in the case of the 1.3. The highst point on the current 1.6 engine IS the filler cap, and its all plastic.

I've reduced it a little by having silver foil covering the grille in the front of the bonnet, except for the bit in front of the air inlet of course. (If you are familiar with the sahpe of the 2002 Astra and similar cars you will know what I mean)

A Looong while back I had a 1.6 Orion - this used to gunge-up the dipstick tube!

Reply to
R. Murphy

This indeed is the situation with the Accent, and is a convincing explanation which I will remember if I ever have to sell the car[rather than run it into the ground which is my usual practice :-)]

many thanks

Reply to
Steptoe

I have had this on a Ford Fiesta. It didn't matter if it did long runs or short there would be mayonaise around the filler cap. I found using Halford 10/40 it didn't do it but with cheaper motorsave (don't know who made it) it did. Try a different oil next time and see.

Reply to
david.cawkwell

Ah, Ford CVHs - "mucky, 'orrible engines" said the local Hometune bloke with conviction in his voice.

Reply to
Carl Bowman

Mainly because most tight arsed owners didn't put decent oil in them or change it often enough. On synthetic or semi synthetic they stayed as clean inside as anything else.

-- Dave Baker

Reply to
Dave Baker

My 911 does it if it's not run for a while then just used for shopping trips. A damn good thrashing cures it though.

Reply to
Pete M

Off with the sump and rocker cover, steam clean all and everything, clean oil pump strainer and breather system, fill with diesel engine oil, change regular, run forever. Rog

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Reply to
PuttPutt

Could be some tosser has topped up the oil filler with water. Then on realising his mistake has changed the oil, but moisture remains in there.

Reply to
a.n.other

The Orion in question was a company car, serviced by the Ford dealership.

When I change the oil I ALWAYS use Castrol - currently Magnatec, and change the oil at least twice as often as the service schedule indicates.. I like my engines to last.

This stuff s overpriced - anyone know where I can get it in larger quantities than the 4.5 litre placcy cans?

Reply to
R. Murphy

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