Air Conditioning/Heating Problem
What I noticed is that ONLY HEAT is coming from all the grilles in the backseat even when the setting in the backseat is set to 12C or to all LOs. There are 4 grilles in the backseat (2 in the middle, 1 in the left vertical pillar by the door, and 1 in the right). Cold air is coming through all the front grilles.
What is going on??? I had to manually turn off (block) the hot air from coming through to the backseat passengers to accommodate them as it was getting really hot.
Any thoughts?
What I noticed is that ONLY HEAT is coming from all the grilles in the backseat even when the setting in the backseat is set to 12C or to all LOs. There are 4 grilles in the backseat (2 in the middle, 1 in the left vertical pillar by the door, and 1 in the right). Cold air is coming through all the front grilles.
What is going on??? I had to manually turn off (block) the hot air from coming through to the backseat passengers to accommodate them as it was getting really hot.
Any thoughts?
https://mbworld.org/forums/e-class-w...rol-valve.html
Any idea how much would the parts cost and where to get it from? Alternatively, my next service is coming up soon. How much would this cost approximately if we do this in-house at the dealership? Is this covered by warranty?
Additionally, on a more interesting note, this problem has resolved itself by this morning. I turned the A/C on and it releases cold air. I switched to the heater and it releases hot air.
Is this normal or should I be worried about relapse?
Additionally, on a more interesting note, this problem has resolved itself by this morning. I turned the A/C on and it releases cold air. I switched to the heater and it releases hot air.
Is this normal or should I be worried about relapse?
Back when I first experienced this phenomenom on my '04 people thought I was crazy... no one had ever heard of it. It is now a well known problem with a well documented cure.
Fix it now while its still cool out. Its not an optional repair. Any time you bring it to the Dealership, its likely that it will appear to be working normally so waiting will do nothing for you.
Last edited by Barry45RPM; Apr 13, 2009 at 03:03 PM.
Additionally, on a more interesting note, this problem has resolved itself by this morning. I turned the A/C on and it releases cold air. I switched to the heater and it releases hot air.
Is this normal or should I be worried about relapse?
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Allow about 2-3 hours for this job. In another thread someone claims it only took 35 minutes, but I don't know how that's possible, even for a pro.
I have very small hands and it was very hard to reach things - if you have very large hands you may not be able to get this done by yourself.
--Open the hood to the fully open service position (push in the tab on the interior side of the hinge, one on each side of the car)
I had a very hard time prying the 4 black plastic rivets out, I ended up destroying them so I need to buy new ones (you can live without them for a few days).
The metal clips: pulling them with the coat hanger worked easily for one of them, but the other two I had to pry the end free with my finger to get it started which raised up one side a bit, them pull with the hanger.
The one facing towards the passenger side was not visible until I climbed up onto the car and stuck my face right down in the area.
After removing the first hose from the engine bay, fully remove the circle rubber grommet between the engine bay and the firewall area - this lets you reach in through the hole to maneuver the part.
The hose clamp is the hardest part - it takes a lot of force to fully open it, so needle nose pliers didn't work very well. Use a small locking pliers and grab it vertically from straight down. Do this after unclipping the 3 metal clips to the other hoses, as you can them move the part around to get it in position.
I moved the hose clamp back a few inches then removed the pliers - you need the space to reach in to pull the hose off. One technique is to hold the part in place by reaching through the circle hole.
I undid the electrical connector last as it was hard to get to otherwise.
When installing the new valve:
-electrical plug first
-large hose with hose clamp next (you need to be able to brace it against the driver's side of the car, against a tool handle etc).
-the two outlets towards the rear of the car next (leave the clips closed and just push them as mentioned about - it did take a lot of force to get them to click into place)
-reinstall rubber circular grommet
-engine bay hose
- get the part number.
- call a few dealers for a price (not all dealers price parts the same).
if you want to know how much it costs to install ask the parts person how much time it takes to replace, according to the service manual.
G.
plus less than an hour of elbow grease. It's definitely something anyone with a few simple tools can do. The stealer would want, $160 diagnostic fees for a start and then they'll talk with u about the other fees.



