300D no heat anyone have an idea

Feb 6, 2009 | 08:18 PM

johnjzjz

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E420

300D no heat anyone have an idea

after the car warms up the heat starts to work than stops and goes cold, sometimes pressing defrost and back to ecom, it will get warm than it goes cold again and wont work again till the car is shut off and re started ???? anyone

Feb 7, 2009 | 02:04 AM

DENIS'S 300SDL

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From: Sacramento, CA

1987 300sdl, 1993 300sd, 1993 300d 2.5 turbo, 1966 200d, 1985 300sd

probably one of the relays. this happened to my 1982 300d, but i dont remember which relay i changed. It works ever since.

Feb 7, 2009 | 04:37 AM

Untertürkheim

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Could it be the monovalve?

Feb 7, 2009 | 05:10 AM

240D 3.0T

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From: Federal Heights, CO

1982 300D VNT, 1980 240D 3.0T, 1982 300TD

Could be the monovalve or the electric coolant pump.

Feb 9, 2009 | 08:18 AM

johnjzjz

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E420

thanks going after it today - jz

Mar 18, 2009 | 05:10 PM

milkman.dan

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From: Oklahoma

1983 300D Turbo

Quote:

Originally Posted by johnjzjz

I have sort of the opposite problem. I will get burning hot air when the A/C system is set to just blow outside air in with no compressor running. Sometimes it will blow ambient temperature air, other times, no matter what it blows very hot air. The monovalve is very recent, less than a year or so old. If it's a relay of some sort, any one know which one? I have a few spares from another W123 I could try.