Mayo oil - Clio MK2

Bear
Posts: 3
Joined: Fri Oct 06, 2017 12:40 pm

Mayo oil - Clio MK2

Postby Bear » Thu Oct 12, 2017 12:53 pm

Hi, I'd like to share some information with you about my old Clio, as I know that this is a common problem.
She was a MK2 2002 8v 1.2, but apparently a lot of other Clio's suffered from the same problem.

My neighbor who sold it to me, was convinced that the cylinder head was gone, but no water was missing from the header tank.
I took the oil filler cap off and it was full of mayo, I had to spoon it out and it filled a yogurt pot.
Also the engine kept dying. The air intake assembly off and it was flooded with mayo from where the engine breather pipe joins it, right up to and including the throttle body.
The water that was causing the mayo was damp air coming from the air intake, the engine breather hose joins the air intake pipe, and hey presto you have mayo.
To cut a long story short, I got rid of the air intake system altogether. I used a motorbike k&n type air filter right on the end of the throttle body; I think it cost about 80p off ebay.
I plumbed in a hose into the engine breather (where it comes out of the cylinder head) and routed it to a catch can. It needed to be emptied every month, which was a pain and very messy. Later on I swapped the 1 litre catch can for a 4 litre oil can tie wrapped to the back of the engine bay.
The car ran much better, with no problems from the throttle body sensor, with the k&n filter it was easier to get to and the performance shot right up.
Mayo was still getting over the oil filler cap, as the diameter of the engine breather pipe (cylinder head) is ridiculously small, the engine was breathing past the o'ring in the filler cap.

I would have opened up this oil breather at the cylinder head (drilled it out), which would have been a total cure for all the mayo related problems. But I didn't get around to doing this as I don't have my beloved Clio anymore, as a stupid girl who likes looking at her mobile phone more than looking where she was going, sent it to the scrap yard.

I hope this information helps, at least get an understanding of why the problem exists, as garages all over the uk are repeatedly getting paid handsomely for nothing more than a clean up job.

ROCAdmin
Site Admin
Posts: 787
Joined: Sun May 22, 2011 1:06 pm

Re: Mayo oil - Clio MK2

Postby ROCAdmin » Sun Oct 29, 2017 4:41 pm

Do you do lots of short trips?

Bear
Posts: 3
Joined: Fri Oct 06, 2017 12:40 pm

Re: Mayo oil - Clio MK2

Postby Bear » Thu Nov 02, 2017 11:55 am

No not really.

Have you ever seen water running out of exhaust pipes, especially noticeable at traffic lights in the morning when the air is damp?
It's water from the air, usually it just gets pushed out of the exhaust but when it comes in to contact with modern oil it turns to mayo. Modern oil has detergent to clean the engine; like washing a chip pan in the sink, add the detergent and a small amount of water and see it turn to mayo. But you probably know that anyway.

An old car may have worn rings causing blow by, pushing excess pressure in to the crank cases and pushing that pressure in to the head and down the breather pipe. On my car the compression was spot on (tested with only one pump of each piston). But if this were the case the engine would benefit from a plenum chamber (expansion tank) attached to the crank cases; then the pressure would have some where to go.

Some have suggested that if the valve seals have gone, pressure enters the head that way. This would indicate that not only the valve's and guides are worn but the valves are not sealing on the head on a compression stroke.

A diy repair to either of the above problems is a time consuming pain, and involves spending money for an old car that has only a short life left. And if the valves or rings are worn then the big ends and mains are not that far behind.

What I have written here is basically a work get around, to save time money or having the car sent to the scrap yard.


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