Possible head gasket

[Joe87]

This question probably comes up quite a lot...if anyone can point to me to a step by step guide I'd appreciate it :)

I'm not much of a mechanic, but I have noticed a lot of steam coming from my exhaust when I start the engine. Checked the oil cap today and there's a bit of creamy stuff on the inside (not very much though). This leads me to believe a replacement head gasket may be in order - can anyone comment on this? Engine still seems to run ok at the moment, no particular loss of power.

Roughly how many hours of work would I be looking at? Is it reasonably straight forward to do? Anything else worth doing at the same time e.g. head skimming, grinding valves?

Cheers guys.

[Funky Diver]

If you've got the head off... and you happy paying for it... better to get the head skimmed whilst you're at it. There's ALWAYS a reason for a gasket blowing, even if it is just old age. Best safe than sorry, else you'll just be putting another gasket on.

[MrD]

Personally i would do a compression test,followed by a gas test,how many miles do you do each day ? Just short trips or decent long journey ? Is it missing at all ? using water ? oikl in water ? Water in oil ?
Might just be down to the rubbish damp weather,if the car is only used on short journeys.

[Nate]

does it use water? are there any traces of oil in the expansion bottle? is there any mayo on the dipstick? if you can answer no to all of those, and the car is runing well then you almost certainly have nothing to worry about.

the steam from the exhaust is normal - petrol is a hydrocarbon, so water is one of the thing produced when you burn it. when it is cold this water will condense into visible vapour. a bit of mayo in the oil cap is normal if the car is used on short journeys - the engine doesn't get warm enough for any condensation inside to boil off

[Joe87]

Ok well I'm feeling a bit better about it after your responses, my dad basically said the same things too.
Yes, it uses water, but very slowly and has done since I bought it over a year ago. There is a little corrosion around the rad too so perhaps it is leaking slightly.
Haven't noticed any oil in the expansion bottle, but I will have a check. Same for mayo on the dipstick.
Unfortunately it is mostly used for short journeys only at the moment, a few miles a day max usually. It does misfire a little when idling when cold, but again this is something it has always done and I believe it is due to a leaky fuel injector causing it to run rich. The exhaust seemed particularly steamy today which is why I checked the oil cap...but perhaps it is just down to the cold weather and condensation.

Anyway thanks for the thoughts guys, I will look into a compression and gas test.

[mclean83]

Take it for a good run, get it warm and drive it hard for at least half an hour. If your head gasket is ok the Mayo will dissapear, however if it gets worse you know you need to get the spanners out. Would be best to get the head skimmed and do cam belt and tensioner at the same time. Also dont use cheap head gaskets, In my experience genuine VW are worth the extra couple of quid.

[MikeH]

As already said - condensation can cause the mayo under the filler cap if you do a lot of short journeys.

Are you losing any water? For a gasket leak to be causing the mayo it would have to be losing water from the expansion tank.

[Joe87]

As already said - condensation can cause the mayo under the filler cap if you do a lot of short journeys.

Are you losing any water? For a gasket leak to be causing the mayo it would have to be losing water from the expansion tank.

As I said, it is losing water but only a very small amount so could this be a leak somewhere else in the system? Will do a long run at the weekend and see if the mayo goes away...

Cheers.

[MikeH]

I've just changed the headgasket, and it turned out I was right to (after 184k miles)

For comparison purposes, the car was losing about 1L of water in 80 miles if driven hard, or 1L in 400 miles if cruising on the motorway at 75 (just been to Scotland and back for the weekend).

If it's not the head gasket, the common places for leaks are round the flanges on the head, which tend to evaporate and leave a salt deposit on the head surface. I normally stick a big bit of cardboard under the car to check for leaks - it needs to not be raining at the time though

[Joe87]

Alright well it's not losing anywhere neeeaaar that much :) I'll try the cardboard trick thanks. When it's not raining...

[Nate]

also worth mentioning, while the health of your cooling system is being discussed: what is your coolant like? it is commonly neglected during services. if it looking brown / rusty colour, add a cup of washing detergent to it (biological for preference) and run it for a week like that, then flush thoroughly and fill with the correct antifreeze mix

[Joe87]

Ok so after a good look today after a long run I can safely say it's not the head gasket. All mayo is gone, none on dipstick, no oil in coolant and no steam in the exhaust. So all clear, even though I was kinda looking forward to doing it... :p However whilst doing that I noticed that the alternator belt was pretty frayed, and sorted that after two trips to Halfrauds who gave me the wrong size first time round. Also I didn't realise that it also drives the water pump, so I'll definitely be keeping more of an eye on it in the future!

Anyway thanks for the tips!