I was just wondering about the heat at the vent temps. On my '82 300D, I put the temp to MAX, fan on auto, with the middle button pressed on the CCU.

That air gets really hot! I used the thermometer that I bought for checking vent temps for the A/C.

With the car at normal operating temp (between 80 and 90C), cruising down the highway, the thermometer stayed at 150F.

In Auto mode and the dial set between 22 and 28C, it will hit the 150F for a while, and when the system reaches it's desired temp in the cabin, it slowly backs of and stays between 100F and 120F.

The Gas furnace at the house runs 120F at the vent.

What numbers do you guys get? When someone said the MB heater is a blast furnace, they were not kidding!

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Since the SD is mixing external air, I don't ever get above 100F.

I have to find that issue..............

The vent temp will also depend on the blower speed....on low the heat in my SD can get pretty intense on the max setting with the engine at full operating temp. My 420's monovalve is not working well, so it barely accomplishes 90F with the blower on lowest speed, any higher and the air gets very cool right away. Good thing its a summer car. It came from south florida, so I doubt they used the heat much.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Is it normal for the blower on auto to run on a lower speed in heating mode when the car is freezing inside? It only gains speed when stopped. it worked perfectly in the summer with A/C - as the fan cycled its speed.

It gets the temperature controlled pretty nicely though.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Nope.

The blower, once it passes it's thermal cutoff temperature, runs a full speed when the interior is very cold.

Either the CCU is not responding to the interior temperature, or the interior temperature sensor is NG.

thanks. I'll check that overhead sensor.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)