300d oil not circulating?? - Page 2 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #16 07-08-2007, 04:02 PM

The oil thermostat is built into the base of the oil filter cannister and the lines to the oil-to-air radiator leave at that point. When the oil gets up to about 100C, the thermostat opens and oil flows to the radiator. Until then, the oil flows directly to the engine.

kerry · #17 07-08-2007, 04:03 PM

Quote:

Originally Posted by vstech

The Oil needs to get REALLY hot before the cooler will even see any oil. it's normal for the cooler to never get hot on a short drive. ya need to go like 40 or so miles with the a/c on to get the motor hot enough to circulate oil into the cooler, and even then, it will only be for a short time, so you could conceivably have hot oil circulate, then stop, then the oil in the cooler get cool, and then you touch it, and feel no heat to speak of.
don't worry about that, get the instruments hooked back up and see what your engine is doing.

Not so in my 85 TD. A short trip around town and oil is flowing thru the cooler as verified with a non-contact thermometer.
I've always wondered about the relative reliability of the thermostats in the system. Nobody ever mentions replacing them, but I bet there's a lot of variation in how they function.

greenjed · #18 08-14-2007, 07:06 PM

By th way it turned out that the used oil cooler I bought was clogged with old oil and not letting anything through. Had it cleaned out and back in the game!