Air-intake filter

[pablo_o2]

I recently wanted to buy a filter unit for the air intake. I have never seen it and it was certainly not installed in my car. Nevertheless according to different catalogues it is existing. So I ordered one and the partsman came with a sort of filter for a cooker hood which can be bought per squair meter at very low prices. He charged 35 € or +/- $ 45 ! I refused of course. My question here
1- do you need the filter installed or not
2- is there an original filter available
3- does anyone have a clear picture of this item
4- why is this so expensive

Regards to you all

Paul Haems
'68 280SL

[J. Huber]

Hey Paul. Are you refering to the air intake (cowl area)? By the windshield wipers? I have heard that others have used a fairly simple filter in there. I have not had a filter in there for 10 years, maybe 20...

[dreyer635]

Check http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02 - engine air intake filter or interior filter? Check subgroup 9 or 83on the web page. You will also find prices there. My car dont have the interior filter - but you must have the engine filter.

Kjell Dreyer
Norway - 69 280 SL 4 speed

[Cees Klumper]

The air intake filter by the windshield (for the interior, not the engine) air is indeed some sort of 'cooker hood' (afzuigkap) material that you can get anywhere for very low prices. The reason it is so expensive from DC probably is because there must be very minimal demand, so for them to stock it has high fixed costs associated with it, which have to be spread out over just a few items per year. Or something like that.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[pablo_o2]

Thanks for the reply, indeed I mean the item listed in the sls catologue under group 83 #13. I think many of us don't have the filter so maybe I just stick to that and forget about putting one in.

Paul Haems
'68 280SL

[gwuisman]

Hy Paul,

I mounted the missing filter in order to prevent water washing into the passengers compartment via the heating system when raining heavely. I did this after I excluded all kinds of other causes of my leaking problem such as replacing the draining hoses and closing holes through the fire wall. Look the following thread http://www.pagodentreff.de/diskussionsforum/t1686-wassereinbruch-kommt-wasser.html?highlight=filzmatte in which I described the way of mounting, illustrated with pictures. Perhaps this will make you think over your decision to stick with the missing filter. I agree with the point of Cees. The filter material is cheep to buy in some household store. But you need the frame which belongs to the OEM part to properly mount the filter. I took a deep breath and bought the expensive part. The results are that the leaking stopped and I am not worying anymore about my floor panels will rust.

Gerard Wuisman
1970 280sl

[J. Huber]

Someone recently mentioned this on another thread but this is a good time to make sure your drain holes are clear in that cowl vent area. If water does get into that area it can drain out properly.

James
63 230SL

[pablo_o2]

Gerard, that is a very good step by step manual you posted there. I think I will buy the very expensive filter and forget about the price some days later...Thanks a lot for posting the link,

Paul Haems
'68 280SL

[merrill]

I have just ordered the seal for the vent flap from K and K mfg for the intake.  
I pulled the cowling off to vacuum out the debris that had accumulated below the cowling.

I cleaned the filter and re installed

I was thinking of using some plastic screen material and mounting it behind the chrome front plate to keep debris out.  

any thoughts?  If I go this I will post a photo.

matt

Matt
66 230 sl - "white"
78 300 D - Blue
98 C230

[91lux]

Hi



Some pictures I took when replaced  the air intake filter. Not to early looking on the dust accumulated. The fan got a easier life after this.Had to repair the flaps (broken shafts,new was put on the list). and exercise/oil the control cable at the same time.
New gasket on the intake cowl flap as well.

I also must mention that it is wise to check the fan housing, even if i had the filter in place the bottom of the fan housing was full of leafes,debris etc. Without AC this is easy to check by taking of the side covers of the fan. I can imagine that the fan can be destroyed if all the debris stuck in the filter got into it, so i recommend to have the filter or some screening in place

Regards 91lux

64 230 sl manual

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[Longtooth]

Maybe I missed something, but the filter described and which is porous for air, to filter out airborn particles and debris, is also porous for water... rain water and other forms.  So how does installation of a new filter prevent the water from flowing into the car?

The statement that "denn diese Matte leitet viel Wasser ab, das dann gar nicht erst in die Luftkanäle eindringen kann." [translation: "... because this mat (filter material) soaks up a lot of water, such that it can't first get into the air channel"] is relative to "how much" water it can soak up, and in any event, even soaking up as much as it can the water remains in the filter... so can only be eliminated by either dripping down into the cowl or evaporating when no air is being forced thru the fresh air vent.... neither of which can occur in a heavy rain while driving.

Seems to me that drain channels and "gummikugelventil"... item 27 in Heizung 83 http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02
might be the culprits... being clogged up.

Of course closing the flap during heavy or continuous rain while driving might be the ultimate solution anyway, but then you lose the fresh-air source to keep windows from fogging up too.

Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport

[Vince Canepa]

Even with the drain channels clear in downpours water gets carried along with the air flow to the vents on the ends of the dash.  Some may not realize this, but there is a port on the bottom of the side air vents.  The early cars have a round hole in the cardboard under dash panel.  The water will drip through those holes.  I usually close off those vents and close down on the inlet flap far enough to stop the problem but still allow some air flow.  This never happened when I lived in California, but here on the East Coast thunderstorms can yield a deluge.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[gwuisman]

Longtooth,

Yes, I guess you missed something. The filter is mounted under an angle. Water getting in the filter will most likely flow through the filter material to its lowes point. That point lays byond the case rim of the air inlet. There it leaks into the draining compartment. When the amount of incoming water is more than the drain capacity the airintake case will function as overflow with water getting into the passengers compartment as result.  That is why closing the air intake flap when it is raining heavely or while driving on a wet road with a lot of waterspray, is recommended. Light rain alows a half open flap. The fogging of the windows can be avoided or prevented by slightly open the side windows or by using the heating fan and directing the airflow to the front screen. Without the filter all water that reaches the opening of the air intake will unhampered flow in the fresh air system causing wet floor panels and rust, also on places wich one cannot see.

Gerard Wuisman
1970 280sl

[Longtooth]

Gerard,
Thank you for that explanation, which is what I was missing... and which now makes sense for why the filter can inhibit mild inflow of rain/heavy fog getting to the air channels inside the car. As an engineer, I even find that explanation and use of the filter at an angle with downside edge overlapping the drain area to be a very clever use of the filter for dual purposes --- particle matter trapping, and water intake trap and channeling flow.  In fact, the incoming air pressure will also be slightly redirected to the down-hill side of the slant of the filter as an aid in moving trapped water to the low side at a slightly greater rate than by gravity alone.  Though I've had my filter out once to clean it (3-4 years ago), I didn't recall that it was held at an angle.

What's interesting to me though is why the air channel wasn't baffeled to exclude the possibilty of any water entering the passenger compartment.... it's not like Germany (& Northern Europe in general) is a dry region with rare event rain.... with the porous filter at the end of the baffled zone so that it only had to catch the finest of fine spray that got thru the baffles.  Cost savings I suppose.

Thank-you again for taking the time to set me straight.

Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport

[hands_aus]

I have always wondered why there is not a screen right behind the air intake cowl chrome piece.
This would slow down the ingress of water and would prevent leaves etc from entering.


Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[JamesL]

Well that was a fun couple of hours

I bought the new MB part from the UK dealer and 7 cross head screws and 4 bolts later, was able to get to the old one. This was sitting horizontal rather than at the angle shown in 91lux's picture. So it was sitting on the two fresh air flaps...

While in there, I de-gunked everything, vacuumed everything and gave it a good clean. Passenger side drain was blocked, which may explain some of the water ingress on that side on wet journies. I also have a little surface rust in there as well . A de-gunk and a quick clean (and removal of air filter...)has done wonders for the heater levers - they move a little more freely!!

It's all still in bits as my flap and rubber seal (above the filter) had both been (over)sprayed car colour and the seal in particular was the worse the wear for it. So.... new seal has been ordered...screws/bolts cleaned off etc.

While it was all in bits I also took a few minutes to clean/grease around the wiper spindles.

James Lester
RHD 280 in DB906 with cognac leather