Gunk in top of oil tank

[20SilkCut]

Quick question - my oil light has flashed a few time so i checked the dip to see oil levels... seems ok. Unscrewed cap to oil tank and on the top of where you pour in the oil there is a pile of 'gunk / goo' type stuff - light brown in colour. Surely this should'nt be here... should it? (and what might it be....?) do i remove or.....
thanks for any answers...

[paddywak]

Does it look like Coffee Cream? If so it sounds like you're gatting water in your oil possibly from a blown cylinder head gasket. I'd get it checked if I were you.

[ChuckFickens]

When did it last have an oil change?

A little brown gunk isn't that unusual and is normally just a sign of a little condensation has got in the oil. as long as the oil on the dip stick looks OK it shouldn't be a problem. if it's a lot of brown gunk you probably need an oil change, if it's whitish gunk then it's a sign of a blown head gasket.

[ChuckFickens]

Hold on....

You unscrewed the cap to the oil tank and where you put the oil in....

Cars don't have oil tanks!

[20SilkCut]

Thanks guys - it looks like coffee cream - and is quite a lot. I seem to remember that the oil was changed maybe about 7 months ago (approx). Oil on dip stick looks ok - dark brownish - and up to normal levels on stick.

[20SilkCut]

Chuck - you are being sarcastic aint ya... course cars have oil tanks.... lol

[ChuckFickens]

Errr, no they don't.

The oil is "stored" in the sump unless you have a car with a dry sump, which is pretty unlikely.

[20SilkCut]

Chuck - ok - i knew the term was'nt 'tank' - could'nt remember the receptacle for where you put the oil in! (I'm only a girlie.... cant be expected to know all the technical details) lol.
So basically (a) get an oil change and/or (b) check cylinder head gasket - that looks like things to get sorted....
thanks :-)

[Buenchico]

As others have suggested, it sounds horribly like a blown head gasket. (When that happens, the surface of the oil is often described as being 'like mayonnaise').

If you continue driving the car, keep a very careful eye on your temperature gauge. If it starts to head into the red, stop IMMEDIATELY (or, at least as soon as it's safe to do so - I'm not suggesting pulling up in the outside lane of a motorway!). If you don't do that you'll probably need a new engine.

Your next question is, I assume, going to be "How much?". A repair certainly won't be cheap. I had the head gasket go on a Ford Escort a couple of year's ago. My local garage repaired it for just under £500 in total (with the job taking around a week) but, as I was delivering parts for a Ford main dealer at the time, I asked several other garages what they would have charged for the job. Most people estimated between about £700 and £900, including VAT, with the main dealer suggesting a repair cost (excluding staff discount) running into four figures.

Chris

[ChuckFickens]

What I was getting at though, is as you don't have an oil tank and you said you unscrewed the top of the oil tank and the where you put the oil in then what was the thing you thought was the oil tank.

If it's the coolant reservoir you unscrewed the top from and that also had brown gunk in it then it is almost certainly your head gasket has gone.

[20SilkCut]

Oh god Buenchico - that's more than the flippin car is worth :-( - i'll contact my mechanic tomorrow and get him to have a look (car is an old 1996 Seat).

[20SilkCut]

Chuck - its not either of the two plastic reservoirs which hold windscreen wiper water, nor the other clear plastic one which holds water coolant, but a large black area in the middle of the engine which has a screw top where the oil is deposited! (am i loosing the plot here?... i've put oil in there before)!! lol

[MASS1961]

As a starter 20silkcut, get the oil changed, use a flushing oil first to clean all the gunk/goo out.
The car is quite old and if you are only doing short trips, the engine isn't getting hot enough to evaporate any condensation that is building up and turning into gunk inside the cap. Occasionally give it a longer run at motorway speeds to heat it up a bit more.
By the way, I know that you are looking under the cap with the oil symbol on it so won't patronize you with oil tank/sump comments.

[harley_Husky]

Chuckfickens was right to point out the use of the word oil tank and i'm sure that no insult to your intelligence was intended. As a mechanic of many years i've seen customers filling the radiator expansion bottle with oil many times ... even intelligent people who have had the car for years ...

So - to business:

Some 'mayonaise' looking deposit is sometimes seen around the oil filler cap due to short little journeys and that being the highest point in the system for any water vapour that is present in the enbine and oil, to solidify and deposit its'self. So before the oil change etc your competent mechanic will do a ' block test '. This usually costs about £15 and involves a glass device filled with some Hydrocarbon sensitive fluid. It is placed in the opening of the COOLANT EXPANSION BOTTLE and with a squeeze of the rubber top 'air' from the coolant is drawn through the fluid. Any Hydrocarbons present will turn the fluid to a wee wee coloured yellow.. ( petrol car ) Whilst this is by no means a conclusive test, it is an indication that combustion gasses ( exhaust etc ) is finding its way into the coolant which would ordinarily be not the norm. Next a pressure test will inflate the coolant system to operating pressure ( approx 20 psi ) any faults in the suspected head gasket will show as a leak of this pressure which can be detected with the stethoscope as a 'pssssssssst' again this is not conclusive but is an indicator of a potential fault. If the car is petrol, removal and inspection of the spark plugs can tell a lot about how the car is running, although without getting too technical, a spark plug removed from an engine which was previously 'ticking over' will be totally different from when it's stuck in the vacuum of your cylinder with the engine revving at 4000 rpm.

You have to weigh up the evidence of all these tests. Oil in the coolant/Coolant in the oil/unusually high oil level due to coolant in the sump/coolant loss etc etc ...

If you're anywhere near Cambridgeshire - i'll test it for you for free !

Best regards & good luck.
Eddie

Now Chuckfickens ... back to those strange circles lol !

[MantaRay]

Unless your engine is showing signs of loosing coolant or performance it's unlikely to be a failed head gasket. What your engine is telling you is that the oil is not getting hot enough for long enough. Bear in mind that oil can take around 10 miles to get up to maximum temp in order to "boil off" the small water content gained by the oil, so numerous short journeys will gradually dilute the oil...which is shy the sludge builds up.

[20SilkCut]

Thanks very much to everyone who took the time to answer. I only normally do short trips every day (less than 10 miles at most) so i can now understand why this gunk can accumulate.
Harley Huskey - thank you for your kind offer but i'm in Belfast - miles away from Cambridgeshire unfortunately! :-(
Chuck - i didnt take offence at all - and now i know not to ever use the term 'oil tank' again - when talking about a car. I did say i was a girlie - i only know the basics about stuff like that.
cheers all x

[Psybbo]

Just had to say hello because of your user name but can't help

[20SilkCut]

Hi Sibton - hello to you too! :-)
Thanks but the kind blokes above seem to have answered my question. ta!

[mjwman]

Just take it for a good long run. A good burst up the motorway.
That should sort it.