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Mayonnaise in oil cap VW Golf 1.6 - gask - arnold2
Mayonnaise in oil cap VW Golf 1.6 - gasket ?

Friends' Golf IV 1.6 (2-valve one) went into National for an oil change, and they told him he has mayonnaise on top the oil - they reckon the head gasket has blown. Could it be anything else? The engine has been running a bit rough on startup for a few seconds then settles down OK.
Mayonnaise in oil cap VW Golf 1.6 - gask - Xileno {P}
Yes, classic HGF symptoms with the rough running from cold. Damp is seeping into the cylinder(s) overnight. Coolant level will be dropping a bit as well, possibly over a week if it's not doing many miles.
Mayonnaise in oil cap VW Golf 1.6 - gask - Roger Jones
I'm not absolutely sure, but I think that mayo on the oilcap can also be caused by a life of short trips, during which the engine never gets properly warmed up to deal with the condensation that happens in all engines all of the time.

Any external signs of oil or coolant leakage (or both) from the top of the cylinder block? That certainly would indicated head-gasket failure. If coolant is being lost but is not showing itself there, check the radiator and hoses for leaks.

Don't panic until the basics have been checked.
Mayonnaise in oil cap VW Golf 1.6 - gask - arnold2
Any issues running it as is for a coupe of weeks until it's in for a service at local Skoda garage, or should this be done ASAP ?
Mayonnaise in oil cap VW Golf 1.6 - gask - Xileno {P}
The cold rough running is a give away, had exactly the same symptom when the HG went on my VW. It could be something else but assuming the garage know their trade, all the symptoms point to it being HGF.

Will run for ages, I used mine for six months more before changing the head gasket. You ned to keep an eye on the coolant level though, mine used about half a pint a week (200 miles approx)
Mayonnaise in oil cap VW Golf 1.6 - gask - arnold2
ah - that's what I was wondering - Coolant - looked OK when last checked a couple of weeks ago but will check with tonight ! Have to check which coolant the 1.6 uses - anyone know ?
Mayonnaise in oil cap VW Golf 1.6 - gask - Aprilia
Doesn't do any good to run with a blown headgasket.

Cooling system gets pressurised and hot steam in cyl head can erode the alloy.
Mayonnaise in oil cap VW Golf 1.6 - gask - arnold2
Doesn't do any good to run with a blown headgasket.
Cooling system gets pressurised and hot steam in cyl head can
erode the alloy.


What should I look for damage-wise when the car goes in (very soon!)
Mayonnaise in oil cap VW Golf 1.6 - gask - Aprilia
Any eroding of alloy head - will need skimming and then pressure testing.
Mayonnaise in oil cap VW Golf 1.6 - gask - arnold2
Weird - checked the coolant tonight - no loss in over 2 weeks ? er ?
Mayonnaise in oil cap VW Golf 1.6 - gask - Sprice
So its your friend's car? What sort of trips does he do? If he does the sort of trips where the engine doesn't reach normal operating temperature, this can lead to mayo. Happened to my sisters new fiesta, so I advised her to take the long way round to work etc and this cured the problem!
Mayonnaise in oil cap VW Golf 1.6 - gask - Steptoe
The Hyundai Accent recently inspected with a view to purchase ( full story later ) had a serious case of mayonnaise so, during and after test run, I paid particular attention to any other signs of HGF. None found, but still negotiated a discount -:)

One month later, mayonnaise as bad as ever but still no signs of HGF. No short journeys since our ownership and the advice I have been given on the uk. rec. maintenance newsgroup is that if the filler cap is plastic and the breather tube exits the rocker cover at a lower level than the cap, mayonnaise is likely to occur.

Obviously this suggests that the problem is model specific, i.e. all Golf 1.6's will be affected similarly, if this isn't the case then maybe gasket has failed
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One mans junk is another mans treasure
Mayonnaise in oil cap VW Golf 1.6 - gask - Aprilia
Get a sniffer test done on the header tank - do away with this guesswork.
Mayonnaise in oil cap VW Golf 1.6 - gask - noel2538
I have exactly same problem with my Golf 1.6 with mayonnaise- Ive been told its because I do some short journeys, still in discussion with VW dearler.

Sorry to be thick, but what is a 'sniffer test'?

Thanks
Mayonnaise in oil cap VW Golf 1.6 - gask - P 2501
A probe is held over the open expansion tank while the engine is running to "sniff" for exhaust fumes escaping into the cooling system from the cylinder.
Mayonnaise in oil cap VW Golf 1.6 - gask - HarlequinVW
It's normal on the mkIV 8v engines, if it's not using any coolant (red type) i wouldn't worry about it. If it is HG failure i would get it done ASAP tho, as head damage will occour if a leak is left, the same goes for external water leaks, the air drawn in when the engine cools eats the aluminium.
Mayonnaise in oil cap VW Golf 1.6 - gask - Mondaywoe
Casting my mind back to a copy of 'Practical Motorist' circa 1975 I recall they gave a template for a 'deflector plate' which you could 'easiy fabricate in the home workshop' - for reducing mayonnaise in Vauxhall Vivas! This thing bolted on around the front of the rocker cover (just above the fan) and apparently allowed the cover to run hotter and thus prevent condensation.

Other suggestions, as I recall, involved 'lagging' the rocker cover with felt!!! (Don't try this at home!)

.....no, I'm not suggesting that as a serious option! Cars nowadays shouldn't need that sort of silliness.

Happy days!

Graeme
Mayonnaise in oil cap VW Golf 1.6 - gask - Roger Jones
. . . and of course you had to find a Vauxhall Viva that worked . . .
Mayonnaise in oil cap VW Golf 1.6 - gask - mjmeloia2002@gmail.com

I have been having a similar problem.

I have a VW golf FSI which has had oil leaking into the coolant tank. Its not been overheating (running at a constant 90 degrees but just noticed some milky residue on the cap for the oil tank (but not on the dipstick). Also external leak from cooling tank .

I really hope there is another explanation rather than a head gasket problem!