Oil - And how breaks down.

[AJRFulton]

I put in a freshly reconned gearbox, and a newly built engine last year. I then had a bad injury and the car sat for 6mths, during which temperatures went as low as -15°.

In the engine I had miller's motorsport running in oil, and gearbox I had Motul gear 300 oil.

When I changed the engine oil from the mineral oil to the Miller's NT+ it was emulsified, I thought I had burst a head gasket, but no glycol in the oil (we can test at work), just high moisture content. I've since did another oil change as part of the running in process and the engine oil is golden.

I'm changing the clutch just now, and drained the gear oil - And same thing - emulsified. The oil has done about 100 rolling road miles. I cannot really see how there is a mechanism for water to get into the oil. Finding it odd it's happened on both Motorsport oils.

You cannot view this attachment.

Any ideas?

[Joesson]

@AJRFulton
My guess is condensation that has somehow formed, the minus temperature would likely assist in that process, in the engine and gear box and when run the increase in temperature, together with mechanical agitation has combined to form an emulsion of the oil and water.

[AJRFulton]

@AJRFulton
My guess is condensation that has somehow formed, the minus temperature would likely assist in that process, in the engine and gear box and when run the increase in temperature, together with mechanical agitation has combined to form an emulsion of the oil and water.

I think it's the reason, but I did a wee analysis at work today on it and was getting about 110k ppm water in oil. That's like +200ml in the oil. It's more than I'd expect.

[Call the midlife!]

I'm thinking weeing in it probably isn't helping...

[Dev]

I do not know what is in Motul 300 but it did not agree with my transmission. It made my synchros engage poorly after 2k miles so I dumped it and refilled with it again with the same fluid and it was ok for awhile but the synchro issue returned and the transmission whined. I thought the input or output bearings were shot so I went back to MT90 and it got better overtime and then all the issues went away.

My guess is the Motul is a race fluid that has a chemistry that degrades when used for street applications or something with the cold as that is when my problems occurred.
I don't remember what it looked like but I don't think it was that bad.

[shnazzle]

I've learned to avoid race fluids. They're made to be replaced almost every time they're used. Racing brake fluid for example is far for hygroscopic, so really it's quite unsuitable for day to day use over time.

The only exception I've found is Fuchs Titan Race ProS engine oil
But...maybe that's kind of a case of Yokohama AD08s... it's for the track...but not.
Or like EBC yellowstuff... for the track....but not.

If you look at anything to be used for race applications it usually comes with a warning, or quite frankly it's illegal to use on the roads (like track slicks - even with tread).

Specifically to Millers; I just drained the Airtrek from its last Millers fill and it was a bit on the foamy side. I;ve never actually seen that before so it grabbed my attention. 
I filled it with Fuchs so...we'll see in 6000 miles

[AJRFulton]

To be fair the car is not road legal and is used as a race car.

I've used these oils for a few years and never had this issue.