CLK 2.7 diesel - heater is poor

[reggie musson]

Hi everyone, could anyone help or advise me if I have a fault with my 2004 2.7 Diesel CLK interior heater, as very little warm air comes out when its set to the maximum heat once the engine is warmed up and I am not looking forward to a very cold winter.

Thanks, Reggie

 

[sheepy67]

i had this on my CLS, turned out to be a £20 part, but buried in the engine, took hours to fix, Acid at MSL fixed it for me, Brabus K8 on here. Get a Star diagnostic on it if you know someone with one

 

[Chrishazle]

First thing to check is that your engine is getting up to proper temperature - scroll through the screens with the buttons on the steering wheel, one of them is engine temperature. I had the same problem when I first bought my S203 C270, engine temp was only getting to 60C instead of 80-90C - had the thermostat changed, problem solved - and a side benefit was an increase in MPG from 40+ to 45+!!

 

[jaymanek]

Yes its the duo valve as mentioned above.. but a real pain to fit... much more common on W211 though, dont think we have ever done one on a 209.

 

[Alex Crow]

No duovalve on a 209, so not that.

As said above, check engine runnign temp.

Also, hard to be sure from reading the original post, but is the blower supplying sufficient air flow??