mg maestro 2.0i

[mg maestro]

it has yellow gunge in oil filler neck and cap as if oil and water are mixing but car seems to run ok im not sure if its head gasket or not of if this normally happens

[daveyboy]

This isnt uncommon if the car does short journeys, we had it in 1989 with our new Mg Maestro 2.0i and the rover dealer did some modifications to try and cure it, they insulated the oil filler neck etc it never did cure it but it never caused any trouble just keep the oil filler cap clean and the engine breathers, my current 2.0i and numerous ones i have owned have all done it some worse than others. I have never had head gasket trouble on any of mine.

[G51 NAV]

Seconded. If there's no other symptoms, disregard it, especially this time of year.

[SimonR]

Indeed - as above.

I've found that different oils cause this worse than others. The one that I've had problems with in the past is Castrol GTX.

I found Unipart part synthetic oil to be among the best.

[daveyboy]

Must admit we ran our 89 2.0i on fully synthetic oil after a couple of years and this dramatically reduced the build up in the breathers etc.

[Jeff Turbo]

it has yellow gunge in oil filler neck and cap as if oil and water are mixing but car seems to run ok im not sure if its head gasket or not of if this normally happens
From Lincolnshire eh, top man

[mg maestro]

thanks for the advice car has no other issues and runs fine doesnt seem to cause a problem just not had car long and never known this to happen before

[G51 NAV]

It's caused by condensation. Austin Rover's solution was to lag the outside of the oil filler tube. The lagging should still be on. If it's missing or badly disintigrated with age, possibly B&Q or a dedicated plumbers' merchant would have something to fit. Not sure how well the cure actually worked though!

[matthewsemple]

Often referred to as 'mayo' in the oil filler tube. Nothing to worry unduly about - just don't put it on your salad!