w4sim

Mine did this for a while, would only blow hot air out if the car was being driven, and only cold if the car was idling.

Seems to have fixed itself, but now i keep getting the "coolant low" warning light and theres steam coming from the top of the radiator.

So you might be low on coolant or there might be a leak somewhere.

merc79

Now I'm getting coolant leak from rear of engine, can't really seem to localize where its coming from, I'm guessing its from the Heater valve because its dripping onto the catalytic converter on the drivers side. Most likely heater valve leaking , if I wasn't on crutches right now I would open that ***** up and do it myself,but now I'll just have to find a way to take it to the local mechanic to have it checked out/fixed.

New Heater valve is like $221. I seriously hope I don't have a ruptured hose somewhere hidden thats connects onto the heater valve.

**on the diagram the Heater Valve is pic 110 for anyone whose interested in seeing the whole layout.

Can anyone share some info on how to get access to the Heater Valve/replace? Like what things need to removed, apart from the cowl under the wiper motor?

w4sim

Are you sure, 100 is just a hose pipe?

Its got to be 110 or 120 i would have thought?

I too need to know which one it is as my rear AC only blows out hot air regardless of what its set to, and regardless of what the front is doing!

merc79

I'm sorry the Heater Valve is #110, my bad. here's the website where I pulled the info out from....

http://www.mbpartsworld.com/showAsse...roduct=7691076

hotgreek

Hey w4sim It might be the drive axle Here in US you can send it out to balance it ..See to it over there ..or try to buy a new one and if don't solve the problem take it back and refund your money...I mean new axle not a car lol

w4sim

If i understand you right, you must mean the long piece that connect the transmission to the rear diff???

Thats what we call the "propshaft" over here. It can be balanced over here aswell, and like i said in my last post, it is something that has occurred to me, but im not sure how it would go "out" of balance to be honest?

Unfortunately over here they are not very good at refunding your money if the part doesnt resolve the problem, once fitted it becomes your property. So the diagnosis has to be perfect right from the start.

merc79

Ok I finally find out where the coolant leak is coming from and why I'm not getting any heat blowing out from vents, its from part# 20 on the diagram(small crack in the plastic tube). This is going to be a pain in the **** job to change out for a $12 Y shaped plastic tube. Can't stand Mercedes making this POS tube out of plastic in such a difficult spot to get to. Plastic + Coolant + Heat + Aging = leaking!

Anyone changed this part out before?

w4sim

Where abouts on the car does this Y-pipe end up then? Dont say somewhere right in the middle of the engine bay!!!

merc79

You got it right, its located in the middle engine bay going into the firewall up to the heater valve. There is another Plastic tube # 25 on the diagram going into the firewall. I'm going to change it as well which is located right below the Y shaped plastic tube. Just to get to this **** tubes you have to remove the wiper assembly and motor and cowl to get a better access; not to mention also removal of the complete driver side air filter box. Still its in a very very tight spot to work in to get the clamps off the tubes and wiggle it loose Going to hopefully have this done on SAT, weather permitting.

w4sim

Maaaannnn, feel for you there.

I hope you get it sorted. It would be fantastic if you took a picture or 2 along the way, especially of the due valve itself, which i would presume to be just above this y-pipe.

merc79

Hey buddy, sorry for the late reply, weather here has been horrid. Still haven't gotten around to getting the new duo valve put in, but I have gathered some important info on the net regarding how to go about changing it. Here's a link I'll be using as a guide to get started. Check out post #9. Regarding the plastic hose; I'll try to take a pic of that once I figure out how to remove the air filter box on both sides of the SuperCharger, any chance you can tell me how to go about removing it??
Thanks.

http://www.benzworld.org/forums/w220...con-issue.html

hotgreek

My heat stop working It was blowing cold air only and I thought the worst I took it to a mechanic and he reset the climate control system and now works fine ..Try this first

speedracer58

My wife's s55 started only blowing warm air. So I tapped (pretty hard with big screw driver) on the heater motor valve under the hood on the drivers side by the firewall, now it gets good and hot. Motor probably going bad.

mercedes4ever

Maybe there is a mouse living in the engine bay lol!

speedracer58

No signs of chewed wires, hoses, no droppings. That can be bad. Fixed many of cars over the years mice, rats and squirrels chewing things up under hoods of cars.

hotgreek

I have a problem last weekend It was blowing cold air and I went to my mechanic he plug the Snap on computer and reset the cooling/heating system and now works fine...Did you try it ?

merc79

Update,
Ok guys finally dropped off the car at my local Indy Merc workshop. They replaced my duo valve and the plastic Y pipe(had a pin point hole in it which was leaking coolant). Now the heat and everything is working perfect knock on wood

After removing the Air box; the access to the Y pipe is easy to do, not as bad as one thought. In my previous posts I have the pics of the duo valve in my previous posts regarding how to access it and change it out.

I'm sorry Wasim I couldn't get any photos of the location of the Y pipe; I told the mechanic to take a few snaps but he didn't. Its pretty visible once you remove the complete Air Box

merc79

Star Diagnosis showed my Pump or valves are not working properly on Duo Valve. Definitely was the duo valve causing the issues....

w4sim

No probs mate, doesnt seem too bad a job once you remove a few things by the sounds of it.

Im sure my duo valve is faulty with my rear AC constantly stuck in hot, but its not showing anything on the STAR diagnostic???

I also have a leak aswell . . . . . stupid radiator has a hole in it!!!!

merc79

Did your mechanic go thru deeply in the A/C Control settings of the Diagnostics, to check if both the Solenoids are opening and closing and if the Pump is functioning? I saw my mechanic go thru the settings which was crazy how he was basically checking everything one step at a time, even the motors of the flaps where the air blows for all the vents front and back and everywhere. Best bet just replace the duo valve bro its pretty easy, I would have done it myself if I wasn't still on the crutches
Hope you get that radiator leak sorted out. Thats a pretty expensive part unless you know where to get it cheap over there in the U.K..
Good luck mate