1991- 230CE Auto Heating Problem.

[benson09]

Hi, Just bought this car which the previous owner had fitted a new radiator in the summer. So due to the cold weather up here in Scotland i put in anti -freeze a few days ago and since then the car heater just blows cold air. I thought the problem was an airlock in the heater.
I have fitted a new thermostat and after seeking advice from other people they also suggested the airlock was in the engine block.
So i have drained the block and topped up the anti-freeze again. ( same result)
The heater inlet pipe is luke warm as is the two return pipes to a set of two sitronic valves ( mono / duo valves ? ) close to the servo unit, after the valves the pipe is single going to a pump ? then back into the coolant pump.
Car temp is approx 88 *C +.
Water does not appear to get past the 2 valves.
can they be repaired? unable to find any info about these valves and the Pump? in the manual.
ANY SUGGESTIONS ?
Thanks for any info.

 

[television]

Hello and welcome,,we have info on the duo valve
http://forums.mercedesclub.org.uk/showthread.php?t=25909

This is info on the valve its self,,,please not htat these valves normally fail in the hot mode. Is there a signal from the control unit in the dash,,one cant measure a direct voltage easily as it is a pulsed signal, though you should detect a difference on a volt meter when going from hot ot cold.

The pump circulates the water, is the pump running ??

 

[television]

please see this thread

http://forums.mercedesclub.org.uk/showthread.php?t=42374

You have no worries with bleeding on a MB as the water is pumped around

 

[benson09]

Hello and welcome,,we have info on the duo valve
http://forums.mercedesclub.org.uk/showthread.php?t=25909

This is info on the valve its self,,,please not htat these valves normally fail in the hot mode. Is there a signal from the control unit in the dash,,one cant measure a direct voltage easily as it is a pulsed signal, though you should detect a difference on a volt meter when going from hot ot cold.

The pump circulates the water, is the pump running ??

There is only a trickle of water if i disconnect the inlet pipe to the pump.
How can i test the pump? Getting hot water up to the heater inlet at the bulkhead then everything is cold after that.
How do i check if there is power getting to the duo valves?
keeping it basic would be appreciated.
Thanks

 

[television]

Has the hose 167 in the link collapsed or blocked,,take it off from the engine and check

http://www.detali.ru/cat/oem_mb2.as...GM=717.413&CT=F&cat=15T&SID=83&SGR=180&SGN=04