Guck under the oil filler cap

HotRodDub

Just noticed this yesterday on my wifes 1999 1.4 Golf. There is cream coloured guck under the oil filler cap. I have read conflicting storys, one being the head gasket going, the other being that this guck is just condensation from the oil then hasnt burned off due to short journeys and cold weather.

The car only does a couple of miles a day.

Any suggestions as to what the problem could be? and what I can do about.

Thanks

jwt

well the short answer is that it's water in your oil.

Where it's come from is more difficult.

If the car is constantly used for short journeys it might be condensation but tbh I haven't heard of this happening in 10-15 years.

Otherwise head gasket is the place to look.

Clean the gumk off, take the car out for a long spin (50 miles plus) take the cap off and clean it again. Check it over the next week or so. If you get the gunk back you have a waterleak.

Condensation style build up takes months to accumalate so if you see it back in a week or so then it ain't condensation.

John

kluivert

Its the head gasket and water is leaking in. Get the head gasket changed and the head skimmed and your flying again on the road.

BrianD3

The gunk is very likely due to the short journeys. As long as there are no other signs of head gasket failure and the "problem" goes away after a few long journeys then you should be fine.

This automatic assumption that gunk under the filler cap = blown head gasket is one of the biggest myths in motoring. And is probably used by unscrupulous mechanics to rip people off.

Oh and a car doing only a couple of miles a day is leading a relatively hard life for the mileage covered. Engine wear will be quite high during those miles and you will get moisture in the oil and exhaust due to it never warming up properly. I'd say you should be changing the oil about every 500 miles in a car doing that sort of driving. It should be getting a yearly oil change at least and manufactuer's recommend mileages of 10,000 miles or whatever should be disregarded.

kluivert

Ok then why is there "guck" under the cap if its not a blown head gasket.

The reason why i said it was a head gasket from was because i had that on an old car i use to have and and car was leaking oil from the head.

I use to have to fill it up every two weeks....the car was in great nick cause it kept getting fresh oil every two weeks lol

BrianD3

kluivert wrote:

Ok then why is there "guck" under the cap if its not a blown head gasket.

Moisture builds up in car engines which don't warm up properly. Burning fossil fuels produces water so its not a surprise. 2 miles a day is not enough to warm the engine properly, unless the car is taking ages to do that 2 miles (eg its stuck in slow moving traffic for the 2 miles)

Now if the car is drinking coolant and there's guck in the oil that would point more to head gasket.

kluivert

Brian you have hit the nail on the head.

My old car use to drink the collant as well, it was a disaster, its now available for spare parts 94 Clio.

I see your point about the car requiring to heat up properly. I hate doing short journeys because i would be aware of engine wear.

So a head gasket failure is leaking oil + drinking coolant + mayo guck under the filler cap.

BrianD3

kluivert wrote:

So a head gasket failure is leaking oil + drinking coolant + mayo guck under the filler cap.

Yeah pretty much. Other common signs of HG failure would be loss of compression, overheating, excessive steam from the exhaust, oily sludge in the coolant. But remember that head gaskest can go in different ways so only some of these symptoms may occur if the gasket goes. For instance sometimes you might get overheating, steam from the exhaust and loss of coolant but no mayo in the oil or sludge in the coolant.

HotRodDub

Cheers for all the replies.

To expand on the details, we are not loosing any coolant, no overheating or excessive steam. The car goes about 1 mile in the morning to work, 1 mile home, and maybe a couple of miles into town for shopping etc. It is a quick mile to work as there is no traffic.

The reason for the low mileage - my car is a diesel so when we are going on long journeys, we take the diesel. The car gets a change of oil every 6 mths. Maybe I'll clean the guck out and I'll take the car for a week instead - my round trip to work is almost 100 miles - and see if the build up reappears.

One thing that concerns me is the fact that it got serviced by VW about 3 months ago and surely this guck did not appear over night. Although the VW garage in town probably didnt even change the oil!!!

Again, thanks a million

koneko

I've seen this on VWs before, I don't think it's anything to be concerned about, and your driving habits (from last post) seem to match with what you're seeing, it's from short journeys. Just clean it out once in a while and keep up the oil change (with good oil).

mike65

Thats just winter stop/start "mayo". Something you might want to check is the pipe that runs from the cylinder head into the air filter box. It might also be gunked up.

Mike.

HotRodDub

I have noticed that pipe 'gucked' up in the past when I've been changing the air filter - but this is the first time there has been guck inside the oil filler cap. In saying that, up until 12 months ago this car was driven alot more.

AMurphy

BrianD3 wrote:

The gunk is very likely due to the short journeys. As long as there are no other signs of head gasket failure and the "problem" goes away after a few long journeys then you should be fine.

This automatic assumption that gunk under the filler cap = blown head gasket is one of the biggest myths in motoring. And is probably used by unscrupulous mechanics to rip people off.

.....

I'd agree with BD3, particularly as you indicated you do very short journies.

this type of engine use is worse than if you have driven 100 miles.

It's worst in winter cause the block is cold or frozen and the air itself contains a lot of moisture to begin with.
The water in the air and from combustion (as well as raw fuel, condenses on the cylinder walls, leaks down by the piston and rings and ends up in the oil.
it is alo corroding the insides out fo your exhaust, so unless you have a stainless ex, expect that to rot from the inside out pretty fast also.

And the combination of water and oil + combustion residue does not make for great lubrication.

In addition you are getting a lot of coak build up in the exhaust from the rich mixture required to start and run a cold engine, which in turn never gets burned off as the whole system never reached a high temp for a sustained period.

So how to get rid of it, you could take the car for a hot 20 mile drive every weekend, change the oil more frequently, ie 2500mls rather than 5 or 10K.

stevenmu

Check the coolant expansion tank for more of it, that would mean a definite head gasket problem, altough not finding any doesn't nessecarily mean that it isn't.

ruby69

kluivert wrote: »

Its the head gasket and water is leaking in. Get the head gasket changed and the head skimmed and your flying again on the road.

got a 1997 mk3 1.4 golf with similar water in the oil problem and am after a quote for head gasket changed and the head being skimmed

fryup

you could try this stuff first.....

https://www.youtube.com/watch?v=3suQy44G_B0

Seth Brundle

fryup wrote: »

you could try this stuff first.....

He has fixed several customers cars that way? Hmmm

Esel

Just posting to say it's 'gunk', not 'guck'. Could be 'gick' though.

HotRodDub

esel wrote: »

Just posting to say it's 'gunk', not 'guck'. Could be 'gick' though.

Excellent point you made there sir, little wonder I rarely contribute to this forum anymore.

This forum just ain't what it used to it, is this a motors forum or an English Grammar & Language forum? No doubt there'll be something pointed out in this post that is incorrect.

Better sticking to our own car specific forums where people actually care and try to help, rather than try to picks holes in someones postings.

Signing out.
HRD.

Barr

fryup wrote: »

you could try this stuff first.....

https://www.youtube.com/watch?v=3suQy44G_B0

Has anyone any experience of this ..seems to good to be true

Seth Brundle

Barr wrote: »

seems to good to be true

What was that phrase again? "if it looks too good to be true it probably..."