Emulsified oil in the rocker box/ valve cover

[Gmg31]

I managed to get my engine running reasonably well yesterday for the first time, federal Renault engine. But I later discovered a small amount of mayo in the rocker box. As part of the project I have had the head skimmed, valves re seated and new water pump.

I've dropped the oil out for another reason and no sign of water and the coolant doesn't appear to be contaminated with oil.

Is there another source of water sneaking in.

[jbcollier]

Cold, rough running engines produce significant amounts of water vapour from combustion.  You normally see this in engines that are only driven short distances in cold weather.  How long since the engine was started after your head work?

[EuropaTC]

Mayonnaise used to be a feature of an old mini van we owned when driven in the winter, it only went a few miles to work and never really got hot. If we gave it a good run at the weekend it would clear.   I have no idea if Renault engines are subject to the same problem, but if you've just been starting it up for a few minutes in the workshop and then shutting it off before it gets thoroughly hot, it might be something along the same lines.

If there's no coolant contamination I'd be tempted to put more oil in and see how it goes when the engine is running for say half an hour at a time.

Brian

edit to add - does this mean you're on the road full time now ? Have I missed the "first run" photos ? 

[Gmg31]

Thank you both for this, I've been having sleepless nights. I've only had the engine running very briefly a couple of times since I completed the head work last summer.  After that I flushed out the coolant with boiling water and flushed out the oil so I'm confident that both were clean.  I will persevere and hope it's what you have suggested. 

Always appreciated.

[Gmg31]

Sorry Brian I missed the second part of your post (too busy smiling with relief).

No the main restoration project is finished but I need to get through the, tuning, MOT and commissioning stage yet. As I'm sure you've experienced even when you think you're done you rarely are.

 After getting the engine running on Friday I had a pool of oil under the sump.  Turns out when I had the sump powder coated the coating filled two bolt holes and because it was so smooth and perfect I didn't notice. So I've dropped the oil and sump and I'm waiting for a new gasket next week.

[Gmg31]

Thought I would have a closer look at the oil today.  Given that the engine hasn't run for 37 years  and only ran for about 15 minutes on Friday I am really surprised how dark it is already. I guess it's cleaning itself.

[EuropaTC]

Wow, that'd make a decent imitation of a pint of Guinness....   

(on the plus side, LED lights or not you aren't going to mistake that for coolant ! )

[pboedker]

I did hear that, Brian.

[Gmg31]

If this was FB someone would LOL. But it's not so I didn't.

[EuropaTC]

I did hear that, Brian.

 

It is black though, isn't it ?  It looks thick and "gloopy" (an advanced technical term) as well although it's hard to tell viscosity from a photo.