Block Heater not working?
 

I have a 1982 300D that I have had trouble starting the past few mornings in Mass, it has been below 20 degrees. This is my first MB and first diesel. I have plugged the block heater in for a few hours before starting, but it doesn't seem to make a difference. I read that when using the block heater the engine should be warm or even hot to the touch, mine is ice cold after several hours, so I assume it is not working. So what next? Should I start by replacing the power cord as it is a cheap part? Is that likely the issue? If not how difficult is it to replace the whole block heater? I know it is rather difficult to get to..... thoughts?

Thanks.

It's possible the cord has simply become unplugged from the heater. You should be able to feel a warm engine. If you have an infrared thermometer it will tell you also. I can usually hear the OE block heater working.
If it has failed, I would replace it with a lower radiator hose heater. 1 1/2" Zerostart works fine. Takes about a half hour to install.

I made sure that mine was actually plugged in to the block.
I then cut off the original 22 year old three prong plug and replaced it. I put on one of those big yellow 110 plugs, a lot easier to grab hold off.

That was a fix for me.

sounds good.. thanks for the responses... is the lower radiator hose heater just as effective? Any negatives to using it compared to the block heater?

I've noticed with my block heater that if I keep the hood closed, the engine will feel warm to the touch in the morning (never hot in my experience), but if the hood is open for whatever reason, I will not be able to feel that the engine is warm, but it still seems to do its job (though probably less efficiently).

When the block heater is pluged in, you will hear it sizzle in the block
with in a few seconds.
Mine is a 400 watt. the one on my old eng. seemed to warm it up more,
the valve cover would be really warm.
I don`t know if they come in different wattages.

Charlie

Close enough. I've got one with an OE block heater and one with a lower radiator hose heater. There's not enough of a difference for me to ever try to get the OE one out for replacement.