A/C - LH cold RH not so cold

[wingco]

w210 320cdi

A/C takes a while to get cold, and does not get as cold as it really should, but not too bad. So I am guessing it may need more gas.

However, the vents in the centre console - LH one air gets cold, RH one air seems to be ambient temperature and not as cold as the LH one. These are the vents above the radio, side by side each other.

Vent on right of steering wheel also ambient, and vent on passenger side cold. If I close all the vents except for the one on the right of the steering wheel, air will eventually cool down from this vent.

Both selector wheels are at the coldest position.

Is this a control problem, or just a general lack of cold air?

 

[kemp2368]

i have noticed a few posts with similar problem,and alot seem to be the duo valve,i dont no ,but might be a option to look at,im sure someone will be along who can say for sure:neutral:

 

[wingco]

Thanks for the advice Kemp I am now looking at the duo valve.

The control signal from both thumbwheels is idendical at between 11 and 12 VDC depending on the setting, (which is a chopped DC voltage apparently), so that rules them out. The coil resistance on each side of the valve is identical at 16.5 ohms, so I think I am looking at a sticking plunger which I will dismantle at the weekend.

Another question - When do the electric fans come on (at the front of the condenser)?

I could not get them to come on yesterday, and there was no 12v supply at the connector, so I figured the system was just not hot enough.

I have seen them woking before on this car but only in the hot weather - would this be correct?

Could I test these fans by simply applying 12V?

The fan spins freely and the drive belt for the second fan is in tact.

Thanks for any advice you may have.

 

[television]

Electric fans on the rad do not cut in until 100c.

This is the arrangement of the air flaps.
http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=F&cat=65S&SID=83&SGR=165&SGN=04

I think that the car needs a re gas by the sound of it

 

[wingco]

Dear Malcolm

Thank you very much for the info. Where is the 100c is that at the surface of the rad or an internal temp?

I am thinking now that the A/C is actually OK. I just tested the air temp at the centre console with A/C running the LH side air temp is 7c and the RH air temp is 14c.

Does 7c sound right for good A/C? it certainly feels ice cold.

Do you think a dodgy flap and not a dodgy Duo Valve could cause my problem? I am still going to try and look at the Duo Valve, but could you suggest how I could test for a dodgy flap?

Thanks again for your advice much appreciated.

 

[television]

You duo valve is 117 in the link, if they stick of fail it will be in the warm mode, there are 2 versions of the 210 this is the early 210026, the last one was for the 210226


http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=F&cat=66G&SID=83&SGR=045&SGN=01


100c for the sensor is in that rad conditions.

7c is not that cold, but maybe cold enough

The duo valve is 60 in this link

http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=F&cat=66G&SID=83&SGR=180&SGN=05

 

[wingco]

Malcolm

I took the duo valve apart, and it was pristine. Checked that each coil worked and the valve was working properly by isolating each coil and then checking for the click when I turned the ignition on. I think I can safely say that the duo valve is working properly.

With the temp wheels at cold, and no A/C on the temp was 19.2c at each centre console vent (engine running blowwer on).

With the A/C on it struggled down to 9.9c on the left and 14c on the right. I figure this is because the evaporator is on the left hand side of the car, but does prove that I am getting some cooling effect from the A/C.

I will get it re-gassed and see what happens. I think the front charge valve is leaking so I will get that changed.

It was re-gassed with dye 12 months ago. What colour is the dye when it comes out?

Is there anything else you think I should check?

When it was re-gassed last year it worked really well.

Thanks very much for your help.

 

[Parrot of Doom]

Turn the AC off (EC light illuminated). Then see if the dials work correctly (albeit both warmer). This will tell you if the fault is low refrigerant, or related to the duovalve.

There's a lot of this on US forums. Low refrigerant leads to one side hotter than the other.