C180 Heater problem

[Knabbel]

Hi, i`m a new member here and i like to introduce myself.
Mij name is Hans and i live in The Netherlands.
I own a C180 Estate, 1996.
My car has a manual controlled airconditioning.
The problem is , when i set te heater at some warmth, there is coming heat from the vents.
After a while , the air is getting cold again and i must set the heater a bit warmer.
Minutes later the air is getting cold again, and so on.
Until the heater is set to full, this happens all the time.
With or without aircon, no difference.
The duo valve is "knokking" while this is going on.
There is a temperature sensor in the lightunit at the seiling, and this is a little fan with a temp.sensor inside.
This little fan is running and i cleaned the sensor, no results.
I checked the duovalve by taking off the plug and it opens completely.

Is there anyone who can help me, please?
With reagards,
Hans.

 

[Ron Palfrey]

Welcome Hans, good to have you with us.
I can't help with your problem - my car does not have air-con, but no doubt someone will come along with some suggestions.
Ron

 

[television]

Hello and welcome Hans, it almost sounds like the water level is too low or an air lock in the system some how

All of the heater is here

http://www.detali.ru/cat/oem_mb1.as...&GM=717.416717.417717.418&CT=F&Cat=44V&SID=83

 

[Knabbel]

Thanks for the reply,
I filled up the cooland level, but no results.
I checked the temperature sensors and cleaned them, messured them and they seem oke.
Any suggestions?

Hans.

 

[Knabbel]

Anyone?
Perhaps an electrical scheme ?

Hans.

 

[Knabbel]

Someone told me it could be the controlmodule,you know with the turningknobs.
Could it?

 

[Knabbel]

tried to read from the cars module , but did not work.
Software keeps telling us "module does not respond or does not exist".
Anyone?

 

[Knabbel]

Problem still exists,no solution yet.
thanks anyway.

Hans.

 

[Hibbo]

Hello Hans, have a look at Parrot of Doom's "how to clean your DuoValve" guide in the DIY section.

I have often found that just taking something apart and putting it back together again can often fix a problem!

Does it stay hot when the dial is turned to full heat?

 

[Knabbel]

I think so, but then it is getting very hot in the car , so i turned it of after a while.
I did take the duovalves apart and cleaned them, but it did not solve the problem.(they where not very dirty)

 

[Hibbo]

Change the temp sensor in the lighting unit.

 

[Knabbel]

Problem not solved yet, it stays hot with the dials turned to full heat .
This is the same as taking te plug of , the duovalve then opens full.
But thanks anyway.

Hans.

 

[Knabbel]

The heater stays hot when on full.
But that is the same as taking off the plug from the duovalve,no power fully open.
I have taking the duovalve apart and cleaned it again, but still no results.
I think I`m not getting any furter here, so thanks anyway everybody.

Hans.

 

[Knabbel]

Problem still exists.
Thanks anyway, I will see a dealer.

greetings,
Hans.

 

[BlackC55]

It is probably the control panel which is at fault.

 

[Knabbel]

I think so too, but I will see the dealer anyway.
Thanks for your reply.

 

[Knabbel]

Problem remains.
Anyone?

 

[BlackC55]

What did the dealer say?

 

[Knabbel]

What did the dealer say?[/QUOTE

The dealer said : leave the car with us and we will fix it.

 

[BlackC55]

Try a second hand control panel from breakers