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Mayo on oil cap

Went to look at a car the other day, as the garage/dealer have had it over 2 months and I guessed it'd been mostly driven short trips (test drives & between the forecourt and the lockup at the back of their building) I'd have expected to find a bit of mayo.

Checked the coolant under the radiator cap - fine.

No white smoke from the exhaust.

Wiped the mayo off before the test drive which lasted around 10 miles / 40 minutes or so - long enough to clear a little bit of mayo remaining on the cap I'd have thought.

After the test drive however more mayo had returned :-/

Checked the coolant in the expansion bottle - fine.

Now then, is it possible for this to be caused by a *lot* of condensation built up over recent months of very short trips that is still making it's way out of the oil - or is it just a good sign that the headgasket is fooked?

Ideally a change of oil and a good run would've been conclusive, but dealers tend not to do anything unless it guarrantees a sale. BTW, the car was 4.5 years old, 28,000 miles and has a full dealer service history.

I know you could say I should just walk away as there's plenty others out there - unfortunately there seems to be only a handful of them up for sale in the UK on Autotrader less than 5 years old. Actually I did walk away (too much of a risk for the price, and have seen a 6 month newer car but with 23,000 more miles :( ), but would like to hear from people with better knowledge than me. I've experienced a tiny tiny bit of mayo on my own cars during damp weather and if they've only done very short journeys (not very often) - but it's always cleared after a good run. I've never experienced mayo to return to the oil cap almost immediately - as mentioned above, coolant is fine, no white smoke, could it just be more condensation making it's way to the top?

Thanks in advance.

Reply to
Johnny
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So, what is it then?

I might just be relevant!

Reply to
Andy Hewitt

Really? ;-)

Reply to
Stuart Gray

The cam cover could have been full of the stuff and it's just been sprayed around by a short drive. It takes a good long run to steam it all out. The cap isn't the coldest part of the engine for water to condense, as it's not even metal, so there was plenty of mayo elsewhere.

There are proper tests to see if the gasket has gone - get an inspection if in doubt.

Reply to
Zog The Undeniable

Er, yes, really!

Reply to
Andy Hewitt

What sort of car?

My '02 Astra 1.6 8-valve, club trim )no underbonnet insulation) does suffer from this in cold wintry weather, and I've got quite used to it. Had it started to happen on my 1.8 Cavalier (with underbonnet trim), or my 1.3 Cavalier (no underbonnet trim), I would have started panicking.

Apart from the trim (keeping it warm?) the breather on the older cars was the highest point in the engine, but on the Astra the oil filler cap is, the breather being a slight bit lower. So I guess there might be a connection there.

Have a good look at the rest of the engine, wipe your fingers around the underside of the cam cover as far as you can reach - if stillgooey, walk away, it means that at the least the prev owner has not been very thorough.

Reply to
R. Murphy

I'd say it's condensation from short runs, as you say. If your ten mile drive took 40 minutes then you really haven't bought the engine up to temperature. I'd say 15 to 20 miles was the minimum to bring the oil up to temp, but if there was a bit of condensation around, that's all got to turn to steam and evaporate, until it's gone, it'll keep doing the same. Owners of 8v 1.9 Peugeot/Citroens suffered from this in the oil filler cap and tube, a bit of lagging or a deflector for the cold(er) air through the rad helped. Vauxhall Vivas suffered from it and a deflector at the front of the rocker cover from the airflow helped.

-- r

Reply to
R

Spot on about the Viva HC I remember it well!

Interesting about my new Astra thoug, I do mainly motorwar (well. it feels like war sometimes!) journeys and still get it in the Winter. VX mechanic, wise old owl that he was, was checking the front shock earlier this year (knocking @ 55k miles, just under 3 years old) and spotted a few days worth of cream on the filler cap - instant comment was "sure sign of driving the car only around town". I simply clean it off ebery weekend, no need in the summer

Reply to
R. Murphy

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