W124 no cabin heat

[television]

Thats a very different pump than the one on my 140 things have changed a lot

 

[Bolide]

It's worth noting that the Duovalve on the E300 Diesel is different from the one in the rest of the W124s. It might be worth checking to see if the correct DV is fitted

Nick Froome

 

[mej]

Bolide - Could not find a part number anywhere on the unit, which I would have checked with the EPC. The DV looks just like the one on my E250DT, which I'm with now, except that has air con, and has only 2 inlets from the matrix, as do all the others mentioned or shown on this thread. The E300DT, the subject of this thread and non air con, is the one which has the 3 inlets. Nevertheless, these make sense. 2 from the matrix, and one from a fork in the inlet pipe to the matrix which leads directly behind the engine (rubber to steel to rubber tubes) and into the 3rd DV inlet instead/as well as going into the matrix. By the way, this is the Tourmaline Green car from Dorchester which I believe you know and I bought in September. You expressed some confidence in the vendor, and he seemed a clued up enthusiast and decent chap, so probably the correct part. Generally pretty happy by the way. Only this fault was unknown/undeclared.

 

[mej]

Conclusion

Well - back with the car for a few days, and so topped up the water, which was a bit low, disconnected the duo valve wiring, and ran the car for around 200 miles including one longish run. Heat present and adequate even in these low temperatures. Reconnected the wiring today and still plenty of heat to do the job continuously over agood hour or so slowish driving. Hence the problem seems to be solved. I think it may have been a combination of the matrix partly blocked - see earlier posts - lowish water (although visible in the expansion tank when cold) and the duo valve sticking. The aux pump can be heard and felt running with ignition only.

Thabnks all for your responses earlier.