Heater box repair costs more than my car is worth!
Sometime back, the little vacuum door that redirects the A/C to the 2 middle vents (vs. sending to the windscreen & side vents) stopped working.
So now, the only places it will blow air out (A/C or heater) is the 2 side vents (not enough flow) and up the windscreen (useless).
(Aside: I can't believe they made that the default, rather than have the air come out the 2 middle vents as the default. If the vacuum breaks, you still get maximal airflow through the middle vents.)
As a result, I've had to make do with turning the A/C on Max Cool with High fan setting to get enough cold airflow when the temps get up over 85°F here in Los Angeles. It can barely keep up.
I finally took it in and asked my mechanic to fix it.
Problem #1. He told me that the refrigerant was leaking someplace, so that's why the cool air coming out the side vents wasn't all that cold. He drained and refilled the refrigerant to fix that.
Problem #2. He then said that the leak was likely coming from the evaporator(?), and that the vacuum leak was coming from the "heater box". He said the evaporator was also inside the heater box, so to kill both birds with one stone, he'd have to get into the heater box.
The catch? "You have to rip apart the dash and the firewall to get at the engine box. By the time you're done, you can actually see the engine from the driver's seat. It's about 20 hours' worth of labor just to get at the thing."
At $80/hour for labor alone, just to pull the box out becomes more money than my 1989 W124 300E (with 201,000+ miles) is worth!!!
Is my mechanic slow? Or is this basically the worst possible positioned assembly in the whole car, and sooner or later, you're stuck with having to get it out to fix it?
Out of about 20 mercedes that i've been "acquainted" with (friends, familys cars) maybe 4 of them had working AC.
I live in NW washington so AC isn't even worth the money to fix it as 85 is just about a miracle in the summer. The Ac in my car didn't work, so when the bearing in the AC pump started squeeling I took out the pump, evaporator, and a little doo-hickey in the fender. After that you just have to go to NAPA and ask for the right size belt. That is the route I would go. For me AC is unneccessary, but my heater still works excellent.
Do you have heat? I have a hard time believing that it would take 20 hours to get to the "heater box". Actually idk what part that is really referring to...
In fact now that I read your post again I have the same thing. No air to the middle vents. Not to be blunt or anything, but I would just deal with it if I were you... I do lol
Either way, good luck! Just remember that at some point it isn't worth the money...
Wolfe190, unfortunately I live in Los Angeles, not Washington State, so "deal with it" isn't really an option ... lol
I guess I'll just limp along with it for the next couple of months and then when we get back to our normal hot-or-hotter-every-day weather, I'll have to put 'er down and figure out a way to get something else. I haven't had a car payment since the late 1990's!
The vent flaps are moved back and forth by vacuum actuated pods, that have rubber diaphragms that crack and leak over time. They can be replaced. Search for a thread by "gsxr" on mercedeshop dot com for very good info.
Yes, the evaporators do often leak, but your indie should do a dye test to confirm that the leak is actually there.
Twenty hours for the total job is not far off. I've done it recently on a 95 E300Diesel. It took me about eight hours to get the heater box out, and another hour to get it open to the evaporator core. There are a few threads by people who have done this job.