Mystery Mayonaise!

[poorly_felicia]

so, friends 1.3 Felly MPI has developed a nasty case of the old mayo-in-oil-cap

However, there are some oddities!

1) NO coolant loss measured over several weeks

2) NO oil globs in coolant

3) No loss of oil

4) Change of oil made no difference

5) No Blue / White / Black smoke or excessive steam from exhaust

6) Valve vlearances checked - all good

7) Swapped spark plugs - no difference and old ones looked fine (no fouling / detonation / wear / carbonising)

im thinking that some piston rings may be knackered, causing blow-by of combustion generated H20 into the crankcase? i cant see what else might be causing it.

All ideas welcome,

ta,

gav

[KenONeill]

That makes me think of a car that's just never getting properly warmed up.

If you're half-convinced about bore wear though, dry and wet compression tests will eliminate that (if you're right, the CR will rise when you do the wet test).

[ap0gee1978]

I've found this gives a reasonable good way of screening out possible HGF:

http://reviews.ebay.co.uk/HOW-TO-TEST-FOR-A-FAILED-HEAD-GASKET_W0QQugidZ10000000001891247

...although you may need to have a lie down after to get over it ALL BEING IN CAPS!!!

[TeflonTom]

it might be something to do with what my sister did to my polo when she borrowed it years ago, she put about 2 litres of water in the oil filler cap...

although it's fairly normal to get a bit of mayo under there, it's just condensation

[KenONeill]

Spare us the CAPS LOCK; is it an exhaust gas analysis kit for the coolant?

[ap0gee1978]

Spare us the CAPS LOCK; is it an exhaust gas analysis kit for the coolant?

No, it's a guide for what to check! Painful as it is on the eyes, it's probably good enough to show up all but the tiniest HG leaks...

[J242]

if i remember correctly, with these engines there is nowhere for moisture/condensation to escape. (somebody please confirm/correct?)

my X reg felly has been in the family its whole life and always had mayo under the cap but never any issues with gaskets/leaks or anything related

[RobinSLXi]

if i remember correctly, with these engines there is nowhere for moisture/condensation to escape. (somebody please confirm/correct?)

Apart from that there breather pipe, er, right next to the oil filler... :p

If you're not losing coolant I'd put it down to the fact it's been cold and wet again the last week or two - I had this exact same worry a couple of months back, but in the end the 'more mayo than I'd ever seen before' on the filler cap really was nothing to worry about.

[poorly_felicia]

I think ken might have hit the nail on the head about the engine not getting up to temp...

its been on the list of "things to do" since i think the thermostat is stuck open and the temp guage dont go up very far. got one ordered today but tbh i didnt see the connection :giggle:

lets hope its just that! i did forget to mention that it still drivers just fine

[J242]

Apart from that there breather pipe, er, right next to the oil filler... :p

oo er thats what that does? ..or doesnt

Edited 7 February, 2011 by J242

[RobinSLXi]

Indeed, stuck-open thermostat + cold weather = mayo galore! Get it fixed, and don't be surprised if it takes a while to clear (mine took 90-odd miles of motorway and A-road cruising)

[anewman]

It's weird that my Favorit never had any mayo, yet my fabia seems to have had it all winter long.

Has operation of the thermostat been checked? Or are you doing shortish journeys?

[KenONeill]

I think ken might have hit the nail on the head about the engine not getting up to temp...

its been on the list of "things to do" since i think the thermostat is stuck open and the temp guage dont go up very far. got one ordered today but tbh i didnt see the connection :giggle:

lets hope its just that! i did forget to mention that it still drives just fine

Now I'm pretty much certain it's just condensation and not HGF.

[poorly_felicia]

It's weird that my Favorit never had any mayo, yet my fabia seems to have had it all winter long.

Has operation of the thermostat been checked? Or are you doing shortish journeys?

lol bit late in there!

we have already deduced its thermostat (its stuck open) and yeah, it doesnt really get to go on decent long journeys.

its weird that i dont get any mayo in my MR2 though that has only been doing ickle journeys of late.....

[TeflonTom]

It's weird that my Favorit never had any mayo, yet my fabia seems to have had it all winter long.

might be because of the grade of oil used in the engine... synthetic vs mineral?

[KenONeill]

It's weird that my Favorit never had any mayo, yet my fabia seems to have had it all winter long.

Has operation of the thermostat been checked? Or are you doing shortish journeys?

lol bit late in there!

we have already deduced its thermostat (its stuck open) and yeah, it doesnt really get to go on decent long journeys.

its weird that i dont get any mayo in my MR2 though that has only been doing ickle journeys of late.....

Some makes and models are more affected than others (says the guy who's uncles ran Hillman Avengers for years).

[anewman]

might be because of the grade of oil used in the engine... synthetic vs mineral?

Ah you could be exactly right, I think I just used cheapie stuff in the Favorit and semi-synthetic and synthetic in the Fabia.

[felicia16v]

and most jap motors dont fill thru the breather system. the oil cap is usually staright onto the cam so mayo wouldn't get chance to gather there. bet if you pulled the breather pipes you would find some tho, its just the coolest part of the system and has the flow of crank gasses thru it.

[TeflonTom]

ooh i've just thought of something that needs to be said.... mystery mayonaise, there's 57 varieties

i'll get my coat :wonder:

Edited 8 February, 2011 by TeflonTom

[FellyMagic]

I thought it was Hellmans

[KenONeill]

ooh i've just thought of something that needs to be said.... mystery mayonaise, there's 57 varieties

i'll get my coat :wonder:

I thought it was Hellmans

Are you guys going to share the taxi?

[poorly_felicia]

Are you guys going to share the taxi?

i can assure you however it tastes nowhere near as good as hellmanns i dont think its something you want with a salad, no matter how hungry you are hahahahahaa

the oil filler on my MR2 does actually have a breather pipe attached to the side, and its not quite straight down to the cams but rather offset by n inch or so with like a little "shelf" under the cap. deffo no mayo (or even a smear of salad creme) even after the smallest cold journey. but then i know for a fact that the engine is in pristine condition :p (its a MK2 n/a with a 3sge for anyone interested in red, i might add )

but, back on topic, new thrermostat+housing+temp sensor ordered, will be fitting soon and will let you all know in due course.

As a side note, would another oil change be recommended when i do the stat' since whats in there, although new, might be corrupted in some way?

[KenONeill]

<meanwhile, back at the point>

As a side note, would another oil change be recommended when i do the stat' since whats in there, although new, might be corrupted in some way?

From my experience (see sidebar about Hillman Avengers, which were notorious for mayo), the most that needs doing is to remove the rocker cover and clean any mayo off it.