John Speake

I had a MAf in for repair at the weekend. It had been used in a c/f s/c car, with the engine air intake filter located under the headlight.

When I took the black cover off the MAF, the reason for failure was obvious - a large amount of water came out. It was clear water, not coolant.

When I queried this finding with the owner he remembered that he had rain water in the intake, and had since made a deflector plate to stop rain water getting into the air filter.

At first I couldn't understand how the water had managed to get into the MAF electronics, because it is sealed where the sensor wires enter the electronics housing. Then I remembered that on later MAFs there is a tiny breather tube - about 0.3mm between the two parts.

Normally there is vaccum in the inlet on a n/a car, so no problem. On a s/c car there is positive pressure and this is what was blowing water into the electronics. I found the black lid was not well sealed, so this allowed the air flow path.

Anyone else with under headlight air filter had problems with water ingestion ?

Tampa 928s

Not yet, but you have caught my interest!
Mine is way up in the fender he must have gone through a large puddle.

John Speake

Is there any way that when the car is stationary, that water can run off the headlight and onto the filter below ?

Tampa 928s

Humm, I guess it could but I try to not drive it in the rain!

stuartph

John


I have found alot of water in my airfilter intake also

I think it is where water runs off the headlight more than being picked up while driving.

Fabio421

Mark, are you running that without the inner fender covers? If so, I would suggest re-installing that one.

Tampa 928s

I have the fenders back on this was a picture during the fitment before I replaced the horns. Seems like some type of shield might be in order.

Jim R.

Anyone else with under headlight air filter had problems with water ingestion ?[/QUOTE]

No problems yet, and I've had mine in a few years now. I think you had my MAF last spring and there were no water injestion issues.

That being said, I avoid deep puddles and try no to be a "U-Boat Commander"!

Jim

Tampa 928s

Makes me glad I did not attend the go-kart night in St. Pete !

Vlocity

John:

That's very interesting.

On my twinscrew set up the MAF is still on the vacuum side. When I was setting up my fender well install I did consider a fliter wrap, which might be an easier fix than experimenting with a shield.

K & N makes one version of their filter cover that is treated to repel water. As long as the filter was properly sized to begin with this should work very well.


http://www.knfilters.com/wraps.htm


PreCharger/DryCharger Filter Wrap Applications

Below shows a list of applications for K&N PreCharger and DryChargers by part number. K&N DryChargers are similar to PreChargers except they have been pre-treated to repel water. All measurements are in inches.

Best regards,

Ken

John Speake

Thanks everyone for their comments. As Stuart said, I also believe that the problem is water running off the headlamp when the car is stationary.