I started my onced-loved 2008 ml550 after a recent snow storm, only to realize that my blower motor froze. I called my dealer who told me to put it in my garage for several hours. I was then told it was a factory design problem. It seems that rain/snow collects from the passenger side hood air vent and collects so that it can freeze and stop the air blower motor.

Has anyone else had this problem? If so, what was the resolve? My dealer suggested everything from covering the vent with a rubber floor mat (unacceptable) to drilling holes in the reservoir that collects the water to allow more drainage..

I am not really loving this vehicle at the moment....

 

Check out the C class w204 thread, a guy on there just had the same problem with his new C. He is waiting for a replacement part.

 

If the dealer isn't willing to take care of the issue or provide you with a REASONABLE solution which doesn't seem to be the case...you could always speak with the managers etc at the dealer if not, make a friendly call to MB corporate

 

I just remembered, and you say yours is an 08 so it probably has this already, but while at the dealership this past weekend I noticed that the new ML's had a wire mesh screen in the hood vent. Only reason I noticed because my 06 doesn't have it, mine is just wide open. Now I know why they did that. Guess they know about the problem and attempted to fix it for the 08 model year, but from the sound of it were unsuccessful.

 

My 06 has the screen. It was delivered to me in Sept 05. I have never experienced this problem even thru 2 winters to date.

 

I just posted this topic onto another MB forum this morning. Here's my text:
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Just had the car (ML320CDI 2007) looked at at the dealership. The service technician says this is a known problem with the MLs and GLs, and some others have reported no heat in their car in the last week here in Ottawa. This is indirectly a result of the heavy snowfalls we've had, plus driver "error" or lack of awareness.

If you start the car with snow on the hood (ie. over the hood air vent in front of the passenger seat) and turn on the defroster BEFORE clearing all the snow off the hood, the snow gets sucked up into the fan area. He said it is blocked by a filter there, so it doesn't blow into the cabin, but after the car warms up, this snow melts off the filter and down into a cup area that houses the fan. It can't drain from here! Once the car is turned off, this water freezes if it is cold enough outside, and the next time you start the car, NO HEAT.

He said Mercedes are looking at designing some form of filter to prevent the snow getting into this area. Once the problem exists, the water/ice is trapped there and you've got the problem. The engineer had to remove the fan assembly to clean the water/ice out of this area.

They've ordered a new fan, since this one is now at risk of rusting the bearings, according to the tech.

So just be sure to clear the snow off your hood before starting the car, or at least don't start the defroster.

Hope this helps others, since it appears to be a preventable problem, although I suppose you could still get it in a really heavy snowstorm while driving around.

 

As an update, after the car was "fixed" by the dealer yesterday, the problem reoccured this morning. I parked outside in -10C (about 20F) and there must still have been water in the vent system that froze the fan again. Either that or the fan motor seized.

The fix apparently involved removing the fan and drying out the ducts with a hot air blower. This sounds like it is hard to get at the fan itself, which must be where the water is freezing. They've ordered a replacement fan, but since they didn't have it in stock, maybe they didn't remove the fan for this initial "fix".

So it's back at the dealer's tonight, and I'll see what they say tomorrow morning. It seems once you've had the problem, it is hard to get all the water out of the fan ducts, and it refreezes once the car is left outside in freezing weather overnight.

As a temprorary fix, park it inside overnight, but this just melts the ice around the fan, and it will refreeze sooner or later.

Does anyone know whether the pre-2007 MLs had the same big vents on top of the hood, or did the fresh air come into the cabin from under the hood?

 

Thanks for your replies. I called my dealer when it was not working and they told me that the ML/GL/R all have a design flaw that causes this problem. As I stated, they suggest drilling a few holes in the reservior to help with draining. The situation happened while driving to get our xmas tree, so the snow was pulled into the vent while driving. It's not something that can be avoided since it happens while driving. The proposed solution to cover the vent with a rubber mat isn't a viable one if you have to drive the car.

Does anyone have a solution for this problem?

 

I got my ML at the same time and I have no screen, just the black plastic mesh thats the vent itself. When I was at the dealership over the weekend, the new ML's have a silver wire mesh under the actual vent.

By the way, I have a new C300 and I mentioned that on that thread someone had the same problem, so it appears to be a problem across the board regardless of the model. Sounds like the best way to stop it is to make sure the vents are cleared of anything that might get sucked into them before you start the engine, ie snow, leaves, plastic bags, what ever.

 

This is just nuts. With all the cold weather testing you see Mercedes doing this is something that should have nipped in the bud long time ago. Totally unacceptable. Any car you buy should be able to be started covered in snow and ice without even thinking twice. Never heard of anything like this. Totally unacceptable MB!

Must be something new because the S, E and others have never had this problem. Only the Bama made vehicles and the new C-Class.

M

 

Thanks for all the replies so far. I took the car to the dealer on 12/27. They installed a mesh filter over the opening in the hood and drilled holes in the blower motor box.
All that had done is to reduce the air flow since it's now restricted and water still blows into the car. I confirmed this when I left the air on when driving through the car wash and ended up soaking wet.
Now,the dealer say that MB has new parts to rectify the issue. Apparently, they now realize this is a problem.. I have mold allergies and can't even breathe in the vehicle.
The car goes back next week for this latest 'upgrade'. Hopefully this resolves the problem for good, as I can't keep a car that makes me sick.

 

I don't get what is so different about the ML compared to MB's cars in this respect. I've never heard of such a thing. All the winter testing you see MB prototypes going through and then you read something like this. I've never cleaned the snow off an MB in that area any more than to free the wipers.

M

 

I havent had this issue, but this stuff is covered under warranty right? The only reason I ask is because like someone had posted, they can claim negligence on the owner's part.

 

I haven't had any problems yet either. But then again..New Jersey hasn't really had a winter yet...

 

Hey kirkg13 did this problem ever get fixed? If so what was the fix and did they figure out what the exact problem was? Reason I ask...my new 08 R350 just had the same problem this morning

 

I'm not sure whether there is an official MB "fix", but there is a work around to reduce the problem. In my case they just replaced the blower motor to the best of my knowledge.

The problem (as I understand it) is caused by light fluffy snow on top of the hood getting sucked into the air intakes for the cabin air, where it gets trapped by a filter which is located above the blower fan. Note that it has to be lots of light snow, since the air goes down and back up through a baffle just in front of the glove box inside the hood. Once the snow gets blocked above the fan, it ends up melting and pooling around the fan blade. A couple of times I could hear the fan blades clicking as they brushed against the ice build-up. In a severe case, typically the car sitting outside overnight after having the snow sucked in the previous day, the melted snow collects around the fan blade or motor and freezes solid.

MB engineers have apparently designed mesh screens or filters to be placed under the hood vents - I think the R-Class has air intakes on the hood of the car, like the M-Class - that help block this light snow from getting sucked in. Also, I've heard that they can drill holes in the bottom of the fan housing to let any melted snow drip out, rather than freezing the fan.

I think a small bit of snow isn't a problem, but turning on the car heat/defroster before brushing snow off the car hood is likely to cause the problem. I'm now very careful about always brushing all snow off the hood before starting the engine.

Note that just letting the car sit inside a garage, or mild weather, "fixes" the problem by melting the ice. But my garage said they were concerned that the fan bearings could fail very quickly after sitting in water, which is why they replaced the fan motor.

Hope this helps. If you didn't have the scenario of fluffy snow on the hood, maybe it is a different problem...

 

I think your workaround is good - I live same part of the world as you and also had to deal with the constant, never ending snow, snow and more snow

I always clean off the vents before starting the car and have so far not seen the problem. I think it was your original post that provided the hint to follow this procedure.

 

It could be I just have a faulty fan as there was no snow when this happened. I drove it in a huge ice storm two days before though and it was like a little ice cube when I pulled it into the garage. The next day everything worked fine, I let it sit for a day and drove my C class and when I hopped in today no fan? Sounds a bit too similar to whats been happening so I'm guessing the ice melted down and refroze onto that screen. Sad thing is I remembered this thread at the time but there was no way of getting the ice off around the vents without damaging the vehicle. Guess I should have made sure to get it all off in the garage after it warmed up instead of just letting it melt...word to the wise.

 

None of this makes any sense. How could MB have this problem with a new model car when all cars (and older MBs) have the same fan location? I don't get this one. Seems like with all the snow we've had here this year more people would be complaining. I've never cleaned my car off before starting it. You simply shouldn't have to do that. Turn it on, clean it off or not, blower should blow regardless.

M

 

Maybe the ducting from under the hood is different now and results in more snow getting sucked up with the air. Maybe the filter to clean the cabin air now traps snow in the air, and it is now located above the fan, so that when it melts from engine heat, the melted snow now falls into/onto the fan case, and can freeze there. I remember in older cars having snow blown into the cabin, since they didn't have filters, which now result in the problem.

I agree it should be designed so it doesn't happen, and don't know how they missed it in testing - never had the right conditions of lots of fluffy snow on the hood? Or the car prep staff always cleaned off the cars before testing?

All I know is that after a big snow storm with the right kind of snow, my dealer reports multiple cars being brought in with this problem. MLs, GLs, and possibly C classses also. It does depend on people having parked outside, and leaving their car out the next night so that the melted snow can freeze around the fan. If you keep going into indoor parking, or the temperature is mild, you'll never get the problem.

 

Well mines fixed...until I get another ice storm! Mercedes is well aware of this problem, my service advisor told me that they sent out a service bulletin on the problem but offered no remedy just a fix. According to him the problem first started in 05 with the new 2006 model ML's and now has effected ML, GL, R, and C class cars.

 

No wonder Mercedes can't get a Consumer Reports recommendation! The C-Class in particular needs to prove that MB has fixed their problems, but this won't help with the type of winter most of the U.S. has seen this year!

I wonder what they changed from the old ML and C to the new one for this to be happening. The CL and S don't have this problem so??? Really strange.

M

 

The air intake vents are on top of the hood for starters, although the same thing is happening with the C class and their intake vents are in the bay with the windshield wipers. Its more common on the ML, GL, and R classes because their vents are on top of the hood where snow can accumulate easier, or in my case ice. I was just pissed cause I read all the threads on here and made a solid effort to remove the snow off there before I started it up, but with the ice there was no way of getting it off without harming the paint or breaking the plastic grills so I just left it. Looking back I should have kept an eye on it in the garage and got out there to remove the ice once it started melting...lesson learned.

 

I am not sure and not understand this at all.

I live in Milwaukee,WI and we have long heavy winter like the other Canadians and like Mr. Germancar1.

I have Ml-320 with almost 85,000(2002 Model Year) and It almost stay outside at My Hospital for almost 12 hours and I never had any problem like this.

Only problem I have noticed that when you open the door snow falls on the front seats and you have to open the door in order to get the snow brush from inside the car!!

BTW any Ml-320 owner has problem with power blower motor? and how much it cost to repair??