Mayonniase on dipstick

[zcacogp]

Chaps,

My much-loved S2 is less than a thousand miles from the magical 200,000 mark. It had a new (rebuilt) cylinder head and gasket last summer (less than 5,000 miles ago) and runs like a swiss watch. It's serviced regularly and kept in very good mechanical order. Having done a couple of hundred miles in it last weekend I can happily report that it is running as well as ever. (A gentlemanly tussle on a fast A-road surprised me by how little a new M4 has over it. Judging from the - glorious! - noise then I think the driver of the M4 was most certainly trying but he didn't seem to know much about balance and corners; in the right hands that car should be a whole lot quicker.)

The bad news is mayonnaise on the dipstick. It appeared before the long trip but I had wiped the dipstick clean to see whether it would re-appear, and it did. There's not a lot; it all gathers on the 'bobble' half way down the dipstick when you pull it out and there is no sign of the stuff in the oil fill tower or under the oil fill cap. However it's making me uneasy. I don't know whether it is using coolant as it always spits the stuff out until way below the 'Min' level (as as has been discussed on here before).

So, in short, what other than head gasket problems can cause mild mayonnaise-ing (is there such a word?) on the dipstick and should I be worried? Is it likely to get worse and should I re-christen the car 'Hellmans'? Is it significant that it only seems to form on the dipstick (and fairly high up the tube at that, as it all appears on the dipstick bobble and not below the bobble).

Obvious next step would be to take the cam cover off and have a look in there but it's cold outside and I don't have a garage.

Thanks,


Oli.

 

[JaseGT4]

Could just be damp dependent on how and where the car is stored? Worth taking the cover off to check the extent.

 

[zcacogp]

Yes, that's my thinking. The car is stored outside, uncovered. However if it was damp-dependant then I wouldn't expect it to return during a long journey once it had been wiped off.

Cover off is the next logical step I guess.

 

[Tommys86]

Hi Oli

I'm still uneasy about mine and I've no mayo in my oil! It's my coolant system that seems scare me, I went for the oil cooler after doing a compression test and checking the cam cover as you say, after the cooler still had issues, then found issue with a coolant pipe and my old radiator appeared to have a leak and suspect all sorts of gunk in it (from the oil cooler issue) - good flush seems to have sorted it but really need to put some miles on it!

Last week was very cold and wet so could well be that "time of the year?"

Compression test & cam cover check....
If in doubt drop the oil...

Cheers Tom

 

[vitesse]

I get this on the Red 924S-done all the right things as well-my gut feeling is that the engine is running too cold most of the time & I think I will replace the thermostat next opportunity.

When in queuing traffic,the fan cuts in eventually with the gauge approaching the red sector,you can see the gauge reacting to the fan & then once moving,the needle reverts down to its usual position -just above the LH white bar.

When I replaced the stat in my wifes grey 924s last summer because it suddenly started to overheat(using the one I had bought for my car)-I found the stat was jammed caused by the wax bulb splitting & ever since then her car has run seemingly "hotter " to her because the needle now always resides just past the centre position-which I believe is the correct position.
Her car has never exhibited any "mayo" symptoms & is used daily including many short journeys.

 

[TTM]

Failed o-rings on the sleeve between the oil thermostat housing and the block can cause coolant to mix with oil.

 

[zcacogp]

Chaps,

Thanks for your answers. Tom, thanks for the detailed comments - they are appreciated.

Given the quantity of mayonnaise (i.e. very small) and the fact that it's not evident anywhere in the oil filler tower then I'm not going to get too excited about it. I need to take the cam cover off sometime soonish (probably when the weather warms up) and I'll have a squiz inside then. A compression test wouldn't be a bad idea but the engine is running as well as it ever has done so I'm hoping for the best.

TTM, I've pondered about that oil cooler arrangement. I'm guessing it's a pig to get to with the engine in the car, non?


Oli.

 

[Waylander]

double jointed and a contortionist Oli!!, but it can be done

 

[jasonp]

Oli,,,if you need a bright garage then your more then welcome to pop yours over here,,,,
i am useless as you know but i would keep you going with lots of cups of tea,,,,,
just give me a call if needed,,,,,,,jasonp

 

[PSH]

I would suspect this to be the cause too Oli although don't know for sure, if you take it on yourself don't forget that you need the OPRV alignment tool for reassembly. If you know someone with a lathe it's a simple thing to turn up, alloy or brass would be fine to use.

Pete

 

[edh]

I think you can use the one-piece OPRV as the guide for reassembly?

Hope it's not too serious Oli - might also be worth doing a quick oil change?

btw that M4 is just a smidge faster...even than an S2 [], although the difference is probably more pronounced at autobahn speeds.

 

[TTM]

TTM, I've pondered about that oil cooler arrangement. I'm guessing it's a pig to get to with the engine in the car, non?

Yes, though it doesn't feel too bad if you can use a lift.
Have to remove exhaust manifolds and the heatshield to get access to all 4 bolts.

 

[Tommys86]

Oli, I've done that oil cooler, unfortunately twice because there is a bulletin out there for measuring the depth of the block port and if required gluing a special sized washer inside.

If you need the alignment pin I had one made - can drop it off/post it to you.

You can remove the oil cooler in situ, I moved the ARB bar and bracket helped - issue I had is the connections to the oil rad are massive and the space is tiny so unless they've come off recently - mine felt welded tight! Once removed I should have really loosen them off but didn't have a vice/clamp to hold them in position so I reinstalled them connected as well - just because life is made up of challenges!

Tom

 

[zcacogp]

Chaps,

Thanks for the replies! I think the next step is to take off the rocker cover and have a look at what's underneath there. If it's clean then I'll relax. If it's mayonnaise-y then I'll need to think a bit more. And if the oil thermostat housing does end up coming off then I'll not be a happy bunny ....

Tom, thanks for your offer of the OPRV guide, I hope I won't need to take you up on it but both the offer and your comments are very helpful and much appreciated.

Jason, thanks for the offer of your garage (and the text message too) - can I keep that offer for future use, either for this job or another one?

Ed, thanks for the comments about the M4. It most certainly should be quicker than an S2, being almost exactly twice as powerful and only slightly heavier! Forgive me for not rushing out to buy one though ....

I'll keep this thread updated with what I find.

Oli.

 

[zcacogp]

Follow-up; I donned my best wooly hat, overalls, scarf and gloves and took the cam cover off just now. If I was Bruno the Belgian from Brussels looking for something to put on his chips - sorry, pommes frites - then I'd be disappointed. Very disappointed indeed. Everything looked exactly as I would expect with not the slightest hint of anything mayonnaise-y anywhere. Here's a photo:

... and here is a photo of some Belgian chips for good measure. You'll see that Bruno found some Mayonnaise (but not in my engine).

I think I can't fully explain where the smear of mayonnaise on my dipstick comes from but I'm not going to worry about it.

Thanks for your help chaps.


Oli.

 

[jasonp]

great news Oli,,, Blimey! those chips look delicious,,,,
of course you can use my garage anytime! and if for some reason you needed to leave it at mine then no problem as i can drop you off home,,
kind regards jasonp

 

[zcacogp]

Jason,

Thanks for the message and your very kind offer. I'll certainly bear it in mind for future use!

Yes, those chips do look good, don't they! Why can those damned Belgos do them so much better than my local fish and chip shop whose offerings are soggy, flabby, formless and tasteless by comparison?


Oli.

 

[jasonp]

Oli,,,
you have the best fish and chip shop in the East End 3 mins from you in Grove rd plus the other one in Victoria Park village just before my nephews fruit and veg shop on the left,,,,,
spoilt for choice sir but i do love the mussels and frites in Belgos,,, jasonp

 

[944Turbo]

Condensation forms in cold damp weather, it gets into the oil and then evaporates when the engine is hot, condensing on cooler surfaces e.g. the dipstick tube, or getting sucked through into the intake and out through the exhaust.

 

[zcacogp]

Tony,

Thanks, it's probably something like that. I'm bemused that it re-appeared, having been wiped clean just before two 2-hour motorway runs, but I guess it was a cold and damp day and I'm reassured that the oil in the head is clear and golden.

Jason, interestingly I managed to eat from The Britannia and The Fish House on consecutive evenings earlier on this year and concluded that, despite there being £1.30 difference in the price of a portion of chips there is no difference in the quality; both are soggy, starchy and equally flavourless. My conclusion was that I'll save the £1.30 in future and eat closer to home!


Oli.