1992 190E 2.6 mono wiper has hard time keeping up when encountering moderate rain - PeachParts Mercedes-Benz Forum

Hans B · #1 12-23-2005, 06:52 PM

Has anyone else had this issue? Even with a moderate rain, I find that the mono wiper doesn't go back & forth fast enough on it's high speed. Which makes driving unsafe and stressful. Has anyone had this same experience and been able to modify the circuit somehow to make the wiper go faster? Or is there another solution? Any comments or suggestions are most welcome.

Regards,
Hans (Atlanta, GA)

AuctorEcclesiae · #2 12-23-2005, 08:45 PM

Hello Hans -

The monowiper, IMO, has a bit more of a difficult time keeping up because of the big area that it needs to cover, and the design of the spring mechanism that makes it "swoosh across the windshield. I do two things to help the monowiper and to improve driving visibility:

1. I bought a bottle of Rain-X and applied a double coat to the windshield.

2. I use Rain-X windshield washer fluid to keep the application "fresh" on the windshield.

Water just beads right off, and when I'm cruising at highway speeds, I seldom even have to turn the monowiper on. You'll still need it at speeds below 40MPH, but you'll notice a drastic improvement in visibility.

Be sure to buy several gallons though, because if your washer tank is like the one in my C230, you can fit about 50 gallons of that stuff in in the tank!

sLoweredK300e · #3 12-23-2005, 09:38 PM

I use Meguiars cleaner wax. One app a month and I never touch the wiper. Very inexpensive, as I use the same wax on my car...

I really never use the wiper, even my DA gf can see with them off, LoL

bobbyv · #4 12-24-2005, 12:40 AM

Quote:

Originally Posted by Hans B

Has anyone else had this issue? Even with a moderate rain, I find that the mono wiper doesn't go back & forth fast enough on it's high speed. Which makes driving unsafe and stressful.

that was the general consensus with the monowiper - that it does not clear the windshield quickly enough in hard rain, even on the high setting. The reason is that it has to complete a wider arc per sweep, compared with one of the wipers in a two-wiper system. And in a 2-wiper system, two portions of the windshield are always "freshly swept" at any given time, compared with the monowiper. Another way of looking at it is that a 2-wiper system has more linear feet of wiper squeegee material.

another reason is that the monowiper inherently has more friction in its actuation mechanism, that makes it extend into the edges of the windshield - running it at a higher frequency would unduly stress this mechanism (as you can imagine from the sounds it makes as it sweeps the windshield).

like others in this thread, I just use RainX washer fluid. On the highway, I mostly need the intermittent or low settings since most of the rain beads away to the sides.

i like the monowiper though - it just looks so cool, viewed from the outside, when it is in action. It looks like a male fiddler crab with its oversized claw ...

Hans B · #5 12-24-2005, 04:58 PM

Thanks so much. I will take ya'lls suggestions re: RainX and the cleaner wax. I agree that it looks very cool, but what was Mercedes thinking (given that they compromised safety of their passengers by having a wiper design that can't keep up!).

Thank goodness products like RainX and the cleaner wax are available.

Do the new Mercs use monowipers still? Or have they switched to dual? I remember some of the MGBs had THREE wipers...for a very tiny windshield. Anyone remember those? ;-)

One day, a high-tech solution will be invented which will do away with wipers all together. I think.

regards,
Hans

haasman · #6 12-25-2005, 02:47 AM

Be sure to lube your mono wiper shaft and inspect the wiper gear, often times it is full of gunk and is in need to a good cleaning and relube.

I agree one wiper isn't as good as two, but a mono wiper working properly isn't too bad.

Haasman

Johnv · #7 12-25-2005, 03:33 AM

I live here in seattle where it rains more often than not in the winter,
I have noticed no weakness with the monowiper although I do use rainx,
I like just the way the water just blows off as if it were the canopy of an F16.
I agree that it would more than likely be a great idea to be sure the mechanism is proper lubed and clean if you belive it is inadaquate or too slow,
mine works great. I'd recommend only buying OEM wiper replacements, belive it's bosch brand.
Cheers!!!

speedy300Dturbo · #8 12-25-2005, 04:54 PM

Quote:

Originally Posted by Hans B

One day, a high-tech solution will be invented which will do away with wipers all together. I think.

A couple of years ago, Acura had something like this on one of their concept cars. The car had no wipers but a powerful blower fan at the base of the windshield. Sounds cool in theory, but it sure wouldn't do you much good when you get mud or bird crap on your windshield.

tvpierce · #9 12-26-2005, 03:18 PM

First thing I'd do: check your fuse for the wiper. I thought my mechanism was starting to bind up because the wiper was going so slowly. Eventually it stopped working all together, so I assumed the fuse had blown. When I checked the fuse, it was fine (but I replaced it anyway.) The wiper instantly came back to life, operated faster than ever, and has worked flawlessly ever since (two years ago). If your fuse has a bad contact, then it will slow the speed of the monowiper. These fuses are notorious for failing in odd ways. Many people replace all of them with updated fuses as a matter of preventive maintenance.

Also, I second Haasman's suggestion for inspecting/lubing the mechanism. If it's working properly, the monoblade should do a fine job at cleaning your windshield.

Jeff Pierce

400E · #10 12-26-2005, 05:58 PM

Quote:

Originally Posted by Hans B

Thanks so much. I will take ya'lls suggestions re: RainX and the cleaner wax. I agree that it looks very cool, but what was Mercedes thinking (given that they compromised safety of their passengers by having a wiper design that can't keep up!).
.....
regards,
Hans

I remember reading a sales brochure from MB, comparing the W124 to a Jaguar (forget which model). They actually were trying to sell the monowiper as a safety feature, as it does actually wipe a larger proportion of the windshield than double wipers (due to the eccentric cam). Just look at your windshield after using your monowiper when you've got dirty slush on the glass. You will see that the swept area of the glass is almost rectangular.

Of course, as everyone above has already observed, the compromise with this design is slower water clearance...

tvpierce · #11 12-26-2005, 09:23 PM

The advantage of the monowiper is that it's clearing the water from the windshield in both directions. In a conventional 2-wiper setup, the passenger side dumps water in the driver's line of sight on the up-stroke, then the driver's side wiper clears it to the center/bottom of the windshield (A pretty crappy design when you think about it.)

One of the better 2-wiper designs I've seen is (remarkably) on a Dodge Caravan. The wipers pivot out from the lower corners of the windshield.

Personally, I still prefer the monowiper.

Jeff Pierce

Impala · #12 12-27-2005, 01:30 AM

The mono wiper on my 95 E320 works fine, and I very rarely have to turn it on high speed (maybe once or twice a year?). It has OE wiper blade, and I don't have any special treatment on the windshield. Just keep the class reasonbly clean before road grime can build up. I won't trade the mono wiper with a 2-wiper setup.