Reasons for Mayo in the oil.

Rich · Post by **Rich** » Mon Jan 17, 2011 4:09 pm

.... apart from the head gasket!

As I've written else where on this forum, I've got quite a lot of mayo in the oil.

The car is not losing coolent and the system is not being pressurised (as far as I can tell) so what other reasons can there be for this.

Bearing in mind that the car has only done 36000 miles in 22 years we can assume that it has spent it's life either sitting around or being run to the shops and back so is a life time of short journeys to blame?????

Any ideas

ken newbold · Post by **ken newbold** » Mon Jan 17, 2011 4:53 pm

Petrol engined BX's have rather a lot of breather pipes, these collect condensation especially if the car only does short runs.

Dollywobbler · Post by **Dollywobbler** » Mon Jan 17, 2011 4:58 pm

I'd be tempted to get a compression test done. If you've changed the oil, I doubt previous use would cause mayo. Did you still have mayo after your run up to Yorkshire?

One thing - are you sure it's getting up to temperature? Can't remember if yours has a temp gauge or not. If it's running cool, that could prevent it getting warm enough to see off the moisture in the oil.

Rich · Post by **Rich** » Mon Jan 17, 2011 5:21 pm

Thanks for the replies Ken and Ian.

The fact that I have changed the oil and done a 500miles-in-a-weekend motorway waft and the mayo is still there has made me write this thread.
Oh and there is no temp gauge so it may be worth seeing if it is being over cooled????

Rich · Post by **Rich** » Mon Jan 17, 2011 5:23 pm

As an after-post-thought.... Should I bung in some engine flush and change the oil again... I didn't use any flush when I changed the oil a few weeks ago.

Dollywobbler · Post by **Dollywobbler** » Mon Jan 17, 2011 6:47 pm

I don't like using flushing stuff.

My multimeter was useful for diagnosing that my BX had a heater problem as it has a temperature probe. Another way is to go for a drive and see if the heater gets cooler as you go faster. When it got really cold recently, the heater was noticably cool at speed (yet actually got lukewarm pretty quickly, so 'stat can't have been fully jammed).

ken newbold · Post by **ken newbold** » Mon Jan 17, 2011 6:53 pm

Is the oil emulsifying or just traces of it in the oil filler and pipes etc?

If it is emulsifying, I think you have a problem.

johnbird · Post by **johnbird** » Mon Jan 17, 2011 6:58 pm

take the rocker cover off and see how bad it is in there?if you wipe it out from the oil fill hole while in place you will get an idea of how much mayo there is.are your breathers blocked? can you get a gas test on the water done? thats a pretty conclusive yes or no for head gasket. if you take the rocker cover off try retorquing the head as it sometimes works for a weeping gasket.an engine getting up to temp and having done 500 miles with a recent oil change should not really have mayo. is the mayo on the dipstick too or only around the oil filler cap?

Rich · Post by **Rich** » Mon Jan 17, 2011 8:01 pm

Dollywobbler wrote:I don't like using flushing stuff.

My multimeter was useful for diagnosing that my BX had a heater problem as it has a temperature probe. Another way is to go for a drive and see if the heater gets cooler as you go faster. When it got really cold recently, the heater was noticably cool at speed (yet actually got lukewarm pretty quickly, so 'stat can't have been fully jammed).

The heater seems toasty and warm to me... Then again I'm used to 2CV's

Rich · Post by **Rich** » Mon Jan 17, 2011 8:06 pm

ken newbold wrote:Is the oil emulsifying or just traces of it in the oil filler and pipes etc?

If it is emulsifying, I think you have a problem.

The oil itself is ok and when I drained the old stuff out the other week it was very thick and black... No mayo came out on draining but there is alot around the breather:

Rich · Post by **Rich** » Mon Jan 17, 2011 8:09 pm

johnbird wrote: is the mayo on the dipstick too or only around the oil filler cap?

Yes... There is a very small amount of mayo around the dipstick tube

johnbird · Post by **johnbird** » Mon Jan 17, 2011 8:13 pm

i would get it gas tested and cut out the guess work then.you could waste hours and a good few quid in oil changes and scratching your head when a gas test will tell you in one minute if its the headgasket or not.money well spent imho,john.

ken newbold · Post by **ken newbold** » Mon Jan 17, 2011 8:27 pm

My guess would be it's just condensation, these engines are renowned for it.

We used to have a 1.6 petrol BX just the same. I dropped the oil and refilled using a diesel engine oil, these oils did/might still have a cleaning agent in that removed all the mayo from the system.

But leaving it in too long could burn your valves out, but should be fine for a couple of hundred miles local running.

I wouldn't mind betting the car lives or has lived outside?

Rich · Post by **Rich** » Mon Jan 17, 2011 8:28 pm

Thanks John... I think this may well be a plan.

ken newbold · Post by **ken newbold** » Thu Jan 27, 2011 12:34 am

Any news