My experience with "frothy" oil is due to water being in it.
That can come from the cooling system, which is where it usually comes from, but it can also come from condensation in the block.
Was it just one oil change that did this, or did it start, and continue to do this?
I assume you have been watching your coolant level closely? The heat is still working fine?
How much oil are you using (burning+leaking) in the 5000 mile run? I would expect close to two quarts added in 5000 miles...
Full synthetics tend to flow more easily at low temperatures (in the same advertised weight) but what specific oil are you using? 10-40 seems fine to me. I think the manual suggests 5-30 dino oil for cooler climates. I don't remember what I was running... I think it was 10-40 dino in my old 1.9 but that was ten years and 70,000 miles ago! Now I run Mobil-1 15-50 synthetic in my S52. The few times I have started it in the cold it was fine (I usually don't drive it in the winter) |