Hello folks.

I have a right hand drive 1999 E300 turbo diesel.

I have an Air Con problem, and have done lots of searches in the Forum. It seems quite common. It's the " left side hot, right side cold" issue.

According to the many posts it's one of two problems, Duo Valve or low on A/C gas.

I took the advice on one of the previous posts and gave the Duo Valve a wack (well, several wacks actually, with the palm of my hand while the engine is running and the A/C on) and the right side is now hot.

And now, when I try setting both sides to cold, the left side gets cold quite quickly and the right side stays hot !

So, to my questions,
1 - Does that sound like a DuoValve problem?
2 - Is the DuoValve servicable; i.e. rather than buying a new one, can I take it off and try fixing it? If so, any tips/gotchas, what is actually inside it ?
3 - How do I check the fault codes on the car? Many of the forum posts have stated that the driver has managed to check the fault codes themselves, and even seen the A/C gas pressure. How do I do that?
4 - My wifes Uncle is an air con expert, but not a mechanic. He will top it up for me, but he won't do it unless I tell him what gas, where the "fill point" is, what pressue to set, and if there are any other details he should know. Cos he doesn't want to do any damage.

Many thanks in advance.

Jim

 

yes.

 

Duo Valve.
Simple to take to pieces and clean so long as you have some DIY skills.
Afraid I can't attach a pic but the DuoValve but it is two small cylinders with attachged wires in the return hoses from the heater sited in the rear or side of theengine compartment.
The valve is basically an electric solenoid. The solenoid must be working OK since ytou have got it to switch from OFF to ON so I guess it is some form of corrosion between the moving parts of the solenoid.
Of course you could buy new ones but I'd have a go at reworking them .
Stuart

 

Thanks chaps. That'll be this weekends job then.

I've seen where the valve is, I wacked it to try and free it. I saw the pipes going in and out. Do they contain coolant ? If so, will I loose much when I take the valve off?

Anybody got any pic's/aticles of "refurbing" the DuoValve?

If not, would it be worth me taking some photos of the job and writing it up (if it works) for others to refer to? Is seems such a common problem I hope someone can lay there hands on some photos or an article.

 

Found a fantastic post on the forum of another Mb site.

http://www.benzworld.org/forums/w210...-cold-air.html

Shows what to expect when refurbing the DuoValve, inlcuding pics, and many gotchas, how to read the A/C codes, how to add gas to the Air Con. All my original questions !

Hope it helps someone.

Jim

 

http://www.eclassbenz.com/node/27

http://continentalimports.com/ser_ic60046.html

try these tips...in case it applies to your model as well

 

Thanks Raymond.

 

I cleaned the duovalve, and the aircon & heater is working perfectly on both side now ! I took photos of the job, and will write it up, in case anyone is interested.

 

Hi

I had the same problem for a while now and I just switch off the engine and start it again and the problem never go away BUT with this step by step tutorial.....I am a happy man...THANKS