Re: Cone Airfilter !!! (archive)

I have the Dinan CAI with a K&N cone filter. These work great now, but I had some serious problems with drivability in the rain and even after hand washing the car, until modifications were made by the installer/ BMW dealer and Dinan. I do not believe the problem was with the filter or the CAI. However, you, and others, may want to be aware of my experience:

In order to fit the Dinan unit plus filter down low in the left front of the engine bay, Dinan instructs to remove some protruding plastic from the top of the brake duct housing for clearance reasons (I am not sure why they do not make the unit slightly shorter to avoid this).
The installer instead cut a 4" diameter hole in the top of the housing. This obviously provides clearance, and allows lots of fresh, cool, air to be sucked directly from the brake duct. However, as I found out, it also allowed water to be sucked into the filter and up to the hot air sensor, causing severely eratic engine behaviour, parts replacement, and potential engine damage.

After several visits to the dealer, by way of a flat bed, Dinan and the dealer finally decided to close the opening, and Dinan provided a "sock" for installation around the cone filter, designed to let air but not water through
( Dinan claims 10% air flow reduction, but filter sized for 300% of required air flow, when new I suppose, so no problem). The dealer also reported to me that there was no oil application on the filter, and that the unit had rusted. See K&N instructions (on web site) for oiling instructions.

The engine runs perfectly now, but it took a lot of effort on my part to get this problem, a serious drivability problem, resolved. BMWUSA Customer Service read about my problem on Bimmer.Org, and contacted me to assist. I contacted Dinan to get them to assist. Both were very helpful and apologetic.

If you drive your car only in the dry, the opening is no problem, and probably gives you some more air and thus power. The dealers initial comments upon the first repair were: "Be careful driving in the rain; do not drive behind other cars in the rain; slow down so that rain will not be splashed up into the brake duct; avoid driving through puddles". Not very realistic for a daily driver. This was also not disclosed at the time I bought the car. I do not know if other maufacturers require the opening. Dinan says it is not required. Perhaps the opening works with oil on the filter, and/or with the "sock".

After the above described work was finally done, the dealer service ticket stated that "Owner should not wash engine compartment, as this will cause air filter to become wet (as evidenced by rust) and wash off protective oil coating, causing engine problems". I am paraphrasing, but the gist was clearly that the problem was caused by me. I took delivery of the car new from this dealer; have had no need to wash the engine.

Anyway, this is more than you asked for, but might be helpful to you and others.

Paul,
'00 M Coupe, T. Silver/ Black, Dinan Stage 4

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Re: Cone Airfilter !!! SteveM 21:35 2/04/2001 (0)

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