Mayonnaise

np · Post by np » 04 Feb 2005, 00:25

Ok,so it`s not a Citroen question,but relates to any car.I`ve just given the wifes Fiesta 1.1 95 M reg the once over as she`s off to Heathrow Fri.Inside the oil filler cap is a load of mayo.And i mean a LOAD of mayo.Yellowish in color.I always thought it was just the stop start routine that caused this.But she does 1 longish run a week.When i serviced it before xmas,i cleaned the whole breather pipes/system out because of this.Its also used a ltr of oil,with no leaks or smoke at all.Ok,its got 110k on it,but runs sweet.
What causes the mayo in the 1st place,& what is it made up of?Anyway of stopping it,& does it do any harm.We`ve never had a car do it this bad[:(!]
Many thanks[:)]

Stuart McB · Post by **Stuart McB** » 04 Feb 2005, 00:43

I've heard an answer to this one. I read on a Ford XR2 forum years ago that this happens because, Ford apprently had a supplier that used an inferior metal casting process for the rocker cover. This lead to air bubbles in the cast of the cover metal. This in turn leads to moisture being trapped in the cover and when heated and combined with oil vapour it gives this dark nicoteen brown sludge, which is apparent in the filler cap. The cycle is self perpetuating as the cover cools so does any moisture and so on. Montego 2.0's were also terrible for it. Only way I found to cure was regular clean out with petrol. You could try and see if the rocker gasket is ok and not sucking any air in to the rocker.

Stinkwheel · Post by **Stinkwheel** » 04 Feb 2005, 00:44

Without head gasket gone its condensation and oil mixing. Condensation obviously from the stop/start use and not warming enough to burn off the water. If only one long trip a week i figure you willstill get some mayo in the cap as it build up the rest of the time. If its really bad its a head gasket (or some other plce water can enter the engine)
Think that covers it.

Richard Gallagher · Post by **Richard Gallagher** » 04 Feb 2005, 00:50

Its normally caused by the engine not getting up to a temperature high enough to evaporate the condensation inside the block, hence the reference to stop-start.
Normally the remedy is a new thermostat/longer runs. Changing the oil and cleaning out the breathers is always a good start to clear any 'build up'.
I don't suppose it does the engine any good because it restricts its breathing and a build up of water where bearings reside.................

np · Post by np » 04 Feb 2005, 00:54

Thanks to all.I`ve known about it for years,but never knew how it formed.When i pulled the filler cap off,a drips of water came out the cap.The cap has a breather hose fitted to it.She does abou 4 miles a day,but then a few longer trips in the week,about a 100 miles a week.I have notice that when i do drive it(not often as i`m 6ft3" & cant fit![:I])that it takes an age to get up to normal running temp,so proberly never gets hot enough to burn the moisture away.
Thanks.[:)]

Dave Bamber · Post by **Dave Bamber** » 04 Feb 2005, 00:55

It's a Ford thing, and Stinkwheel's post covers it. I used to see it when I was in the trade years ago, usually in Fiesta ohv engines driven once a week by little old ladies. I took the rocker cover off one once and the cover was so full of stinky gunk, the shape of the rockers and valves could be seen in the mess. Yumm!
Edited as I'm not implying your missus is a little old lady[B)]

np · Post by np » 04 Feb 2005, 01:29

No,she`s not a little old lady,though sometimes i feel that she is![:D].
It is a ohv,so maybe i`ll take the cove off as its easy,& have a good clean up.

p20 · Post by **p20** » 04 Feb 2005, 01:56

My Astra had a plastic[B)] rocker cover. I was convinced the condensation forming inside it produced the mayo. It was ok in summer, but bad during the really cold winter months. I ended up with two sets of breather pipes so i could change them on a weekly basis.

bikeboyz · Post by **bikeboyz** » 04 Feb 2005, 02:08

Once took the rocker cover of a 1.3 push rod escort F plate, and it must of had a good inch thick inside of mayo. I also recall reports of Peugeot 305 doing something the same in Diesel Car magazine (when it was a proper mag!). I agree its basically condensation and oil. If a pushrod engine gets the valve clearances checked on a regular basis, the routine of clearing out mayo should be followed.

Dave Bamber · Post by **Dave Bamber** » 04 Feb 2005, 02:08

NP
Give the breather a clean out too, and maybe if you can, replace the oil filler cap if it's part of the breathers too. Easier than trying to clean it out.

np · Post by np » 04 Feb 2005, 03:14

Yes Dave,it looks part of the system too.Has a metal gauze inside it,like a filter.When i serviced it,i cleaned the whole lot out.Blew through all the pipes,the gunked it all.Shes done about 1500miles since.I would take it to work once a week,which involves a bit of motorway.But,i dont fit in it to well[:I][:o)],it only does about 80mph,90 at a push.No good for overtaking etc.....
And the last time she drove the Xantia,she curb`d the alloys![:(!][:(!]

alan s · Post by **alan s** » 04 Feb 2005, 03:30

Haven't heard of this one for a while, I always thought it was the forte' of the BX
Back when BXs ruled by numbers on these forums, this was a common fault that can take ages to find the cause of. Everything from prayers to witchcraft were used over the years on it, but eventually I think it was the concensus that the existing mayo had to be cleaned out as water and reciprocating parts don't mix. Not only that, but moisture begets moisture and as it condenses in one area it usually reforms in others so it's essential to drain the oil and clean out the breather and filler pipes as well as flush the engine to be sure it's all gone. (May sound a bit extravagant but usually cheaper in the long run.) Mineral oils are more prone to this than synthetics or semi-synths but engine condition and previously used oil grades will determine that to a point.
Replace the thermostat straight away. As an example, I just replaced a thermostat on a BX TZi. It used to run around 70 degrees and when taken out and stood alongside a new one, showed itself to be about 10% open at all times. My 16V also had a new one fitted and in both cases, the cars now hit the optimal operating temp, around 90 degrees within a couple of miles. Cold engines operating in wet climates with hot combustion chambers and exhaust are the perfect mix for condensation.
So if you go flush, change, thermostat, I'd reckon your troubles will be very much lessened if not totally removed based on BX experience.
Alan S

oilyspanner · Post by **oilyspanner** » 04 Feb 2005, 16:54

I get the same problem with the Volcane TD, SWMBO does about ten miles per week, thermostat etc good but theres condensation in there, needs a good drive occasionally and once well warm a bit of an italian decoke, that and frequent oil/filters even though the miles do not say so.
Stewart

modi · Post by **modi** » 04 Feb 2005, 17:48

np, always wanted to know, whats the yellow sticker [:)] on your front car - passenger side - its the tax disk i think which is usually blue[:(]/red[:(!] in color, but it seems to be a traffic warden ticket!!![}:)]

np · Post by np » 05 Feb 2005, 00:47

Tax disk holder,white.Caravan Club Mayday Breakdown Service.The rectangle bit at the top of the holder is for the membership card to slip into.