3B oil level rising

[scunginator]

My 1985 3B appears to be gaining level in the sump. How quickly it is and in what conditions it does it I'm not completely certain of yet, but it definitely isn't coolant and it certainly is abnormal.

I presume diesel would be the only other thing likely to contaminate, but I'm having a hard time trying to work out how it could possibly get into the sump in any meaningful quantity.

There's no external fluid leaks, and because there's nothing leaking out it stands to reason nothing can leak in, if there was anything on the outside in the first place. It can't be coolant, as it holds its pressure and doesn't lose a drop from the overflow & the system proper. No milkshake, or even a hint of a one, anywhere.

I'll try to get a better idea over the coming days, but I thought I'd post here before thinking I'm losing my mind.

 

[duncanrm]

The inline pump does have an engine oil feed and an oil return through the timing case. A failure in the Lift Pump, or an internal issue with the inline injection pump could lead to diesel ingress to the engine..

 

[Runner]

I had this problem, mine turned out to be the lift pump ( the one with three nuts and holds the primer)

 

[maximBJ70]

I've seen this with diesel getting past the rings and increasing the engine oil level. Not a good thing as it required a rebuild of the entire engine. I'd recommend a compression test to rule it out.