About one month ago over the Labor Day weekend I drove to El Paso, TX from Colorado. The interior of the car was quite hot (> 80F) for the last 200 miles or so. The ambient air temperature outside the car was 91F (not that hot, right?). I turned the thermostat down from the usual 72 to the blue dot, but it made no difference at all. The fan was on the highest speed the whole time but the air that came out was only mildly cool.

IMPORTANT NOTE: This is NOT the hot-air-into-the-back-seat-area problem reported earlier by several E-500 owners. My car is a 2003 E-320.

It was 4:00pm Friday when I arrived in El Paso with a three-day holiday weekend just in front of me, so I took the car to the first independent service place I could find. Their advert in the Yellow Pages said they specialize in air conditioning and Mercedes-Benz automobiles. They checked four things: (1) compressor, (2) plumbing, (3) diagnostic port and (4) don't remember the fourth thing. They found no error codes, no leaks in the plumbing and the compressor had normal compression. Also, the air conditioner seemed to be performing normally for them and continued to perform normally for the rest of the five-day trip. (They charged me $45 for running the tests. European and American Automotive, Freddie Silva, proprietor -- nice guys, all of them, and they knew their stuff.)

Back in Colorado, I notice that the air conditioner sometimes does not work correctly again, just as in the El Paso trip. The secret seems to be to shut off the engine, wait a while and start it up again. Presto! It works!

There are three authorized dealers in the Denver area along with a couple of respected independent service places: (1) Walter's Star Service and (2) Stu Ritter Service (yep, the guy who used to be the president of Mercedes-Benz Club of North America and wrote a book entitled "E-Class Bible"). I am loathe to take the car to any of these places because I feel I'll just be charged a lot of money and they won't find anything wrong.

Any suggestions from the Forum? Anyone experience this before and what was the solution?

Andy

 

I am just wondering if your coolant temperature has something to do with it.If it gets to a certain temperature,it will cut of the AC.....

 

The more I think about this, the more I think you might be right. The coolant temperature in my car seems to hover somewhere over 100 deg C most of the time. I wonder how hot it has to get before it cuts off the air conditioner?

I've decided to take it to Stu Ritter in Denver. I'll report back, if there is any interest.

Andy

 

I thinks it is 102celsius just above water boliling point

 

For the USA guys... Wouldn't you assume that setting the display up in the English Language and displaying units in miles (& MPH instead of KPH), and the heat/a-c temps in to display in Farenheit, not Celcius, would also make the Temp display in degrees Farenheit? I know the cluster is silk screened with the "C" next to the guage, but I assumed that that is an oversight for this market and the display is really displaying the coolant temp in F not C.

 

Although the previous shop found no leakage, temperature fluctuations and non-cooling issues are normally associated with low refrigerant level. I would suggest recommending a leak test using fluorescent dye as per MBUSA DTB P-B-83.00/97a.

 

I want to address the issues raised above.

(1) The problem was not excessive coolant temperature nor was it a low refrigerant level. The leak test using fluorescent dye was done (suggested by konigstiger) and the system was found to have no leaks whatsoever.

(2) Yes, the markings on the display for coolant temperature are stenciled in degrees Celsius and I believe they are actually in deg C. Deg F would imply that the operating temperature of the coolant is just above human body temperature. No way does it run that cool!

(3) The problem was determined to be a faulty blower regulator which is operating correctly some of the time. The determination was made, the mechanic at Stu Ritter Mercedes told me, after extensive analysis of the error codes which were dumped into his laptop from somewhere. (He told me the place, but my poor memory cannot recall the name.)

So, in a nutshell: $450 for a new blower regulator. It's my first expense for this four year old car, so I'm certainly not disappointed yet. I just hope these sorts of repairs do not become regular.

Andy

 

Interesting..I had a the blower regulator changed on my w210 and w126 but in both cases the blower itself wasn't running.

 

I had a couple (3) of Blower Regulators replaced under warranty 1st year on my '04 because the fan would cut off whenever the unit went into max cool or defrost modes.

What you paid for the job was not excessive for parts & labor IMO.