Hello, with my 2.5 td runs the viscolufter 10min. after cold start, with therefore always also at 15 degrees outside temp. I remember that my former BMW 325i – E30 also at 30 degrees outside temp. has not always run along. When the temperature goes up he turns fully with, then the clutch then leaves again however again, etc. only the 2.5 td (bmw tds machine) know eh probably all *gg*. turns always full with. Test I have already done, when cold is turns he smooth and no storage problems (test if is loose) fazit: viscolufter must be ok. I have looked here already many times since I am here but I have not found the answer to the question here: does the viscolufter run even at 15 degrees outside temp. always at the Omega 2.5 td with?? is it with yours also so? Considerable is also that it always indicates below 90 degrees (water) it never seems to be really warm. Info: heating goes very well?