'06 E320 CDI Operating Temperature
 

Below is a pic of my CDI's engine temperature indicator earlier Wednesday, 11/27. Putting around town on surface streets at 35 mph after 15 minutes, with an ambient outside temperature of +43F.

Is this too cold? The temp. increased Up by one bar, right after I shot the pic.

Did you have the heater on? Not surprised to see it that low if it was just an "around town" trip at slow speeds and it is cold. Should come up some if you put it on the interstate at 80 mph.

I started my CDI up last Sunday night around 2am at Dulles airport in Washington, ambient temp was 17F at the time and the car had been sitting for over a week so it was as cold-soaked as it could be.

In spite of the fact that we almost immediately were at 60MPH on the way home it still took a good 15 miles before it got up to operating temps, its easy for me to believe that at lower speeds it might take quite awhile for it to get up to temp.

What's really strange is that you almost immediately get heat out of the heater? Apparently there must be some sort of resistance or ceramic heater in play?

It's also quite common for the thermostat to fail in these cars, when I got mine it wouldn't get over about 50-60C unless it was over 60F ambient.

Instruments are often fed by a separate sensor than the ECU which can show up as a lag in the instrument indication. I have a scan gauge that I use to verify such anomalies.

I was suspicious of the thermostat in my work truck because gauge reading never left the lowest mark in the normal operating range. The scan gauge revealed that the engine was happily operating between 205 and 210 degrees.

There is a 1000 watt electric element in the heater to help bring the cabin up to temp more quickly.

My blue tech takes a good ten miles to fully warm on a cold morning, so this appears to be typical of modern diesels.

Thanks for making this thread...I am having the exact temperatures in my '05.

Never hit 80*C+ anymore unless I'm stuck idling. Interstate or surface streets below 40*F = low engine temps.

Guess it's time for a thermostat or should Skid Roe Joe and I check the temp with a scan gauge?

I find it interesting that the engine doesn't warm-up more (quickly), especially since there is no full-time fan on a pulley throwing air propelled by the engine turning - only the electric auxillary fan unit attached to the radiator assembly when the engine's temperature warrants it.

I am really liking this new to me MB diesel sedan. Wish the headlights had more candle-power though.:o

I have noticed a similar trend with my car as the ambient temperature gets cooler. Putting around really does not work that engine, and I believe it is just taking that much longer to reach operating temperature. Nothing to worry about.

These direct injected engines don't warm up nearly as fast as the indirect injected ones. (OM606 and earlier)