PeachParts Mercedes-Benz Forum - View Single Post - Modification for D-Jet M116 and M117

Greg in Oz · #5 04-07-2005, 04:32 AM

Gary,

Even in Sydney we do get occasional heavy rain. I had considered the possibility of the cold air intake ingesting water however I don't believe it will be a problem.

Firstly, the air velocity into the intake pipe is only high at wide throttle openings and high engine speeds, an unlikely situation in heavy rain.

Secondly, looking at the pictures I posted, you will notice that water would have to get through the grill, then the holes in the panel between the headlight and radiator (oil cooler on that side actually), then the intake pipe which runs uphill to the flexible hose. If water does actually get beyond the flexible hose, there are a couple of small diameter holes at the bottom of the original intake pipe of the air filter which should allow it to drain. If water could even get past here and reach the air filter element, the air velocity is lower through the much larger cross-sectional area of the element itself and I doubt the water would get beyond this point, instead lying at this low point within the filter housing and eventually evaporating.

To reinforce my reasoning, both my 190E and 300TE have original factory fitted cold air intakes behind the grill with little to suggest they would prevent rain water being ingested any better than my DIY cold air intake on my 350SLC.

As for additional material being collected in the air filter that may be possible, particularly larger objects such as insects. Again, I don't expect this to be a great problem since the air filter element has a very long life and the filters on my other cars with original intakes similarly located don't have a problem with the air filter becoming contaminated quickly.

Greg