please help i have just bought an x reg 1.9d kangoo, the problem is i have very thick gungy oil in coolant expansion, i cant find an oil cooler on the engine anywhere, the oil filter is on the block but no cooler,there is no water mixing with oil in engine as oil is clean, but it is really bad in header very thick sludge,van seems to have reasonable power and is not smoking at all any ideas thanks. Oh also on drive home lost 5thgear completely will engage but its like neutral.other gears are fine