C220 CDi Cold Running

[oigle]

A good idea, but seemingly it is not available as a seperate part, or rather, no one has been able to find a part number for it (including the guys at MB).

Yes, that was the issue - no availability. Wonder if I should look at a tap in the hose, manually operated. Would be a bit more professional. I could put it in place of the thermo and just open it when I felt the situation warranted - towing etc. Sqeezing the hose would work but damage to the hose would be possible/probable in the long run. Bit agricultural too.
Wonder if there is a suitable in line thermostat available from another usage or make? Might be worth a bit of investigation. Seems this issue could be quite widespread.
Alex, do you see ANY issues with taking the low temp rad out of the system for normal usage? The heat exchanger still operates exactly the same as I understand it except that the water at the exchanger will be some degrees warmer. This could result in the auto tranny fluid working at a higher temp, but presumably still at an very acceptable level during normal load usage. I see this unit (low temp rad) being there because MB in their wisdom have approved the ML for towing up to 3500kg, which is quite high and would put enormous heat loads onto the auto tranny. Is that as you see it? Trying to be careful here!!!!

 

[Alex Crow]

All I have is theory here, and knowng that they are fine without the 'stat in Finland does not really help if you are in Queensland.

I confess to not being able to picture the 'stat on a 163, but on a 203 it is mounted in front of the aircon condensor. The odd thing about it is that it cannot really be opened by its coolant, unless it has a bleed to allow constant slight flow through it. I wonder if it is intended to respond to the residual heat around the radiator and condenser, particularly at idle? Not sure on that one.

 

[mersum1es]

A good idea, but seemingly it is not available as a seperate part, or rather, no one has been able to find a part number for it (including the guys at MB).

but certainly there is number when you remove the failing stat, and after that google give for example:
http://www.weidl.net/shop/de/Regler...-Mercedes-Nr-A0052033975.html?xaf26a=belxnfci

 

[Alex Crow]

but certainly there is number when you remove the failing stat, and after that google give for example:
http://www.weidl.net/shop/de/Regler...-Mercedes-Nr-A0052033975.html?xaf26a=belxnfci

And thankyou for that! A good number, and only £23.65 inc vat.

 

[oigle]

All I have is theory here, and knowng that they are fine without the 'stat in Finland does not really help if you are in Queensland.

I confess to not being able to picture the 'stat on a 163, but on a 203 it is mounted in front of the aircon condensor. The odd thing about it is that it cannot really be opened by its coolant, unless it has a bleed to allow constant slight flow through it. I wonder if it is intended to respond to the residual heat around the radiator and condenser, particularly at idle? Not sure on that one.

Wondered about that myself and assumed there must be a bleed flow like a normal thermostat. Haven't even gone looking for the stat - just assumed it must be there:Oops:
On another point, I wonder what temp the inline thermostat is supposed to open at? After all, it is called a "low temp radiator", so one would logically think it must be less than the 82° of the main thermostat. Maybe it is supposed to open at 65° and we are chasing shadows. My temp issues all started with the loss of heat from the EGR manifold after the shunt. I immediately noticed a marked slowdown in reaching op temp after the mod and, maybe coincidentally, the op temp reached was generally lower - perhaps the small rad was doing enough cooling with the egr heat eradicated, to almost control the overall heat in light operating conditions. I think this motor is very slow to produce heat and the egr heat loss just added to the problem. My motor will currently get to 75° after the little mod to the main thermo but takes 20km to get there. Gets to about 65° after about 5km when I assume the low temp rad cuts in. Slow rise from there.

 

[Dev6969]

Hi All,
I'm new to this forum. I've enjoyed enlightening myself with all the common issues we as MB owners have. My C220 has been a cold lady since I bought her 5 months ago. Also have issues with the climate control , this will be left as is 'cos like many am not spending silly amounts to repair.

I shopped for a thermostat at a local motor factor and was quoted £130 for a generic one!!! I approached the local MB dealership and was pleasantly surprised at their price. £43.08 and in stock. Fitted it on Monday myself. Not to difficult a job thnx to a post by Malcolm.

Now my cold lady is a warm and inviting lady. ;-) within 5 miles I can see temp gauge moving and feel warm air blowing.

 

[cs48zar]

Hi, Alex here... new to the forum...
So I have an estate C200CDI w203 (or S203) year of production 2002. I am from Romania and vehicle is from Germany (1st owner worked as an engineer at Siemens). This is just as an intro. I am the 4th owner in the cars history and I've been fixing a lot on my car. Car has OM611.962 engine (85kw 6 speed manual gearbox).
So to fix the ****** issue with the second thermostat which is found in the front of the car behind the two horns I was about to purchase the original part a0052033975 - sadly I couldn't source it from anywhere. What I will try to do is buy a VW part 1K0121113A and try to retrofit that. Honestly speaking this is the only part which I could find to come in similar shape and has a 75 degree starting point to open and a full opening of 80 degrees. If someone else can find a thermostat that opens at around 80-85 degrees then that is also a good thing.

Just thought to share this info with the rest of you.
Probably will do a video on youtube about this.
Thank you all in advance.
BR,
Alex

 

[Blobcat]

Hello and welcome

 

[glastry]

HI , its been a while but i do appreciate this forum.
this is the first winter in 10 years that i have suffered the northern temperatures!
i knew that i had to do something about the temperature in our c class c270cdi,
and i can confirm that if you change the thermostat , in front of the radiator and behind the horns
you will have heat!!
i used the one from the VW PART mentioned above and YES it works.
thanks to all posters!!

 

[flookie]

Found this video from June 2020

(I believe this is Alex, cs48zar - Thanks Alex if it is you) on the part original secondary thermostat part a0052033975 to VW part 1K0121113A - Just about to replace it myself. You have to remove the inside of the VW part and add it to the case of the MB part. Looks easy, but I have not done it yet. I am wondering if I have to drain the whole coolant system in order to change the part. Any advice would be appreciated.