[Breach]

Guys need some advice on two (maybe) separate issues:

1. I changed oil in September. Until last week it was at max green level according to the sensor (don't recall what the dipstick was reading). Then, all of a sudden last week sensor would say oil level too high. I drained some off and I think it was up to 0.5l (half a quart) above the max. I'll send a sample for analysis now, but I suspect diesel dilution . From what I can see that's typically because of:

a. Aborted DPF regens (possible, as I was doing city trips only during that time)
b. Leaky injectors
c. HPFP leaks

Of course, I might have slightly overfilled last time too. Otherwise, no visible contaminants / smell in the old oil.

I've changed oil again and note that dipstick reads 1/4 under the max and sensor reports max green light level. I also forced a DPF regen and did a highway drive. Will monitor, but any thoughts?

2. Coolant issue - for at least the last 3-4 years I've noticed that I am losing a small quantity of coolant - basically in one year the amount between min and max level in the expansion tank. I know it's a closed system, but the loss is so insignificant I've been ignoring it for now. But maybe I actually have a leak and need a pressure test. What's your experience?

Btw, no faults in ISTA.