Road Flooding

Lusso916

Junior Member
Messages
78
Just to be safe, where are the air intakes on a 4200 ? are they where I think, down near the side/fog lights, dont want to fill the engine with water.
 

Scaf

Member
Messages
6,555
Interesting question, we were talking about driving through floods in the pub yesterday and most people seemed to be more worried about the exhaust rather than intake - took a while to get them to reconsider !
 

Oneball

Member
Messages
11,107
My dad wrote his 5 series off in the last floods. I went to get him. The water was only at my calf.
 

2b1ask1

Special case
Messages
20,262
It is the opening at the bottom on the near side bumper just over the splitter. The air box is actually fitted with water release flaps on the back but they may as well not be there for the good they will do!

I'd suggest that the moment the splitter is in the water you will scoop up water into the air box, the bottom of the stock air filter is resting on the floor of the box and being paper will mop up even small amounts, it will very quickly become overwhelmed and as the engine is acting like a great big pump you are in trouble before you know it!

Best thing I did to my 4200 was rip out the air box and go K&N in the wheel arch up behind the headlight. At least it could breath and not drown.

The GS is awaiting similar treatment I just haven#'t needed to get the bumper off yet.
 

2b1ask1

Special case
Messages
20,262
If ever you have the front bumper off it is easy to remove the ridiculous air box as the rubber mounts will be rotten anyway. Then just a straight silicon hose from the MAF through the inner wing hole and the biggest souble cone K&N you can get hold of on the end and a single bracket or better still a 10mm wide electrical reusable zip tie onto the back of the headlight bracket means you can easily remove it for washing/oilling through the wheel arch liner opening.
 

TimR

Member
Messages
2,731
Ive just recently done this mod Newton is recommending...

I would advocate measuring the size of cone you can get in there as I could have gotten way bigger..but it wont necessarily clear the liner. Or nestle it inside the headlight frame without serious 'rubbing'; and you get very close to the road which, for me anyway, part of the process was to get the intake up off the floor some...!
I literally took dims of the favourite filters and made a cardboard maquette in 3D and offered it into the available space...
 

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2b1ask1

Special case
Messages
20,262
Yes it is possible to do without taking the bumper most of the way off but only by cutting off the arm tube at the top of the box to get the box out making it impossible to put back to stock should you want to.
 

2b1ask1

Special case
Messages
20,262
I couldn’t wrangle the OEM airbox out of the 4200 without removing most of the bumper on that side, how did you do it?