190e heater, temp always hot !

[johntom]

Hi
on my 190e the temperature controls (both driver and passenger) don't effect the temperature from the heater - it's always hot. Even the blue 'cold' bit is still hot !
Any ideas out there, the car has just had a new water pump, thermostat and coolant refill etc (along with a head gasket) - don't know if the temp. control worked before all this.
thanks

 

[television]

Its normally the duo valve on the heater that seizes up, could be a vacuam or electrical issue, but the valve is a known problem.

Malcolm

 

[C220GJS]

Check that the duovalve has not been unplugged for some reason as it defaults to fully open when it loses electric power, also check your fuses, if the are the bullet type they are a known problem and although they look alright they may be making poor contact in the holders.
Duovalve is normally at the drivers side rear of the engine bay in front of the brake master cylinder.
Cheers, Geo.

 

[johntom]

Hi
thanks for that, is the valve a white looking piece (with a little arm on it) almost under the bulk head - connected to a small hose going through the firewall? if so where would it be disconnected?
thanks

 

[C220GJS]

Sorry, I must be mistaken in assuming your car had solenoid valve control for the heater flow.
Is this the valve you see , http://catalog.eautopartscatalog.co...&model=190-E-005&category=R&part=Heater+Valve ,if so it is vacuum controlled and is a single valve in the heater hose, check that the vacuum line is intact, if so the fault must be in the heater controls, any idea if they have been tampered with recently?

Can you give the exact year and model of your car?
Geo.

 

[johntom]

Hi
yes that's the part!
the car is a 190e, 2.0 auto (1991, H reg)
where would i find the vacuum pipe?
many thanks

 

[C220GJS]

Hope this helps,http://www.detali.ru/cat/oem_mb0.asp?TP=1, find your car and work your way to the system you want. The heater valve is on the top left of the heater system vacuum diagram.
Cheers, Geo.

 

[johntom]

Hi
PROBLEM SOLVED !!
I felt behind the heater dials and realised the conecting rods behind the dials were off both sides, obviously someone had been in there before(don't know why?) !. After dismantling and removing the center console i was able to reconnect the rods back into the rear of the dials. Now i can see out of the windows when it rains !!
many thanks for pointing me in the right direction.

 

[C220GJS]

Well done, it's usually something simple with heating ,often ,as you found someone else's shoddy work.
Geo.