Heater problems

[CrazeUK]

Make: Mercedes
Model: C220 CDI
Transmission: Auto
Fuel: Diesel
Body type: W203
Year: 2001

Hi Guys.
I fix one issue, and then something else comes up.
Anyway, I recently had an issue with the car going into limp mode.
On initial investigation i removed and cleaned the EGR valve, then finally found out it was the Mass Air Flow Sensor, which i replaced now the car is great.

Since then, i noticed my heaters do not work properly.
I am not sure if this is related but i am sure they worked while the car was in limp.

The main vents that heat the passenger zones do not blow out hot air, instead a constant stream of cold air.
The corner vents that service the windows blow out hot air, so does the windscreen heater and the foot well.

Like in the diagram below:

The air con works on all the vents correctly.

The only way i can actually heat the car up is if i roll the green arrow to closed.

Any help would be great. Having cold wrists is painful!

 

[television]

I would have thought that it was normal, see what other 203 owners say

 

[huey]

I dont think warm does come out of those blue arrowed vents, as TV see what others say.

 

[CrazeUK]

Hey guys, sorry i hadnt got an update that any one had responded.

My main issue is in winter the car didnt get very warm.

Also it doesnt feel like thereis a lot of air coming from the blue vents when the heater is on (which maybe explained if the blue vents only allow cool air).

p.s. TV.. your fantastic!

 

[thejohn]

I have a W203 and my car was not blowing too. hot so I changed the thermostat then all was well. that was thanks to great info from this forum. but first I would check the engine temperature and ensure it's reading 80c + first if not the thermostat is the most likely culprit.
John

 

[television]

A car that only reaches 70c will feel very cold, they have to get over 80c to feel any warmth at all, blown air does have to be hot to start with

 

[CrazeUK]

So is it bad if the car doesnt get to 80c?
My BMW seems to find it easy to get hot even when its minus temps outside (and they show readings upto 32c, as opposed to the mercs feable 26 lol)

 

[television]

My 140 was the last example of this,,it got to just under 80c and the heater was awful and never to warm. The problem is the on the open road the temp can go down without you noticing it. With the new stat all normal with a constant heat and exact settings

 

[CrazeUK]

Ah ok that explains why, when i was stood in traffic and not motorway driving (which i do a lot of) the car did actually feel warmer.

You would think it being a merc and 2001 it would cope better. Well i will check the thermostat.. but i think its a problem solved.

 

[television]

Ah ok that explains why, when i was stood in traffic and not motorway driving (which i do a lot of) the car did actually feel warmer.

You would think it being a merc and 2001 it would cope better. Well i will check the thermostat.. but i think its a problem solved.

Mercedes thermostats have a shorter life than almost any other car that I know of

 

[mattkh]

Mercedes thermostats have a shorter life than almost any other car that I know of

Hi
Do you know the name of the brand they use ?

 

[CrazeUK]

Also do you mean the cabin thermostat in the climate control unit. Or one for the engine

Sent from my GT-I9100 using Tapatalk 2

 

[CrazeUK]

So having driven today down the m62 for an hour and it being a windy 13.5c I checked the temp for the car. It read about 50c. I presume this is outside of what it should be?

Aside from the fuel mixture being rich and my cabin heater not working what else will this affect?

Also anyone know where I can find the sensor?
Will it need replacing?
Will the diagnostic show it?

Sent from my GT-I9100 using Tapatalk 2

 

[Chrishazle]

I had a similar problem on my S203 2001, engine temp never getting above 60C. Had the engine thermostat changed (it's another MB special where you have to buy the housing as well as the actual thermostat, costs about £35 IIRC), afterwards the engine got to 80C+ and the heater worked well. Side effect was my average MPG went up from about 41 to about 45!

It's a job you can do yourself - there's a very detailed how-to on here by Helpthisdude - http://forums.mercedesclub.org.uk/showthread.php?t=65685. Title is for C270 but first line says C220 is the same.