Hello all,
After heavy rain as soon as I start my P38 I get water flowing down from under the glove box. It only lasts a 20 seconds or so and then stops. This is with the climate control/fan switched off.

If I have the climate control switched on then I get lots of water flow into passenger footwell. I can hear it being spun around by the heater blower motor.

I have sealed off all around the pollen filter cover but it is still happening. Does any know where to start looking for the water getting in?

Throughout this summers dry weather it hasn't happened so I know its rain getting in rather than O rings leaking in the heater system.

Thanks in advance.

Could be from the windscreen leaking or the sunroof + when you sealed the pollen filter did you do all the screws I ended up taking the whole panel and right across the front of the car to seal all the screws

EssexP38 said:

Hello all,
After heavy rain as soon as I start my P38 I get water flowing down from under the glove box. It only lasts a 20 seconds or so and then stops. This is with the climate control/fan switched off.

If I have the climate control switched on then I get lots of water flow into passenger footwell. I can hear it being spun around by the heater blower motor.

I have sealed off all around the pollen filter cover but it is still happening. Does any know where to start looking for the water getting in?

Throughout this summers dry weather it hasn't happened so I know its rain getting in rather than O rings leaking in the heater system.

Thanks in advance.

Click to expand...

I take it you have cleared the A/C drains?If not suspension set to high, axle stands under chassis, slide under, arm up between the bellhousing and body,have a feel around and you will find two rubber balls,for a better word,give them a squeeze to open them and you should get an arm or two full of water and crap.drains clear.

If you have a sunroof the sunroof drains. This was my problem

Rubberknees said:

If you have a sunroof the sunroof drains. This was my problem

Click to expand...

Where abouts? Any more details on that?

The pollen filter cover(s)

Take them off and run a bead of silicone around them, also blob some on the screw heads.

domino said:

Where abouts? Any more details on that?

Click to expand...

Open the sunroof fully and down each side just in from front (get some tall steps to look down from) you will see the drain holes. I used the old fashioned net curtain wire (couple of quid from Wilko) to feed down and clear the blockage. Nice and steady and it worked fine. Its now a twice yearly job

Henry_b said:

The pollen filter cover(s)

Take them off and run a bead of silicone around them, also blob some on the screw heads.

Click to expand...

He said he did the covers don't know about the screws..

tomcat59alan said:

He said he did the covers don't know about the screws..

Click to expand...

Yep.

They also warp in the middle, so you need a good amount of silly cone

Rubberknees said:

Open the sunroof fully and down each side just in from front (get some tall steps to look down from) you will see the drain holes. I used the old fashioned net curtain wire (couple of quid from Wilko) to feed down and clear the blockage. Nice and steady and it worked fine. Its now a twice yearly job

Click to expand...

Strimmer cord works as well.

At last said:

Strimmer cord works as well.

Click to expand...

Good first post.welcome.

Or a few metres of core from twin n earth?

I use an old LAN cable.

Is it rainwater or coolant?

There is a video on Youtube where the fellow removes all of the cowling under the wipers to re-seal everything to prevent water leaks. You might have a look. On my 98 there was a leak where the door frame metal butts up against the roof metal. This let water run down the windshield frame on the passengers side.

OK I've seen this...Living in Seattle it rains for months on end, and the RR sits outside and for long periods. So this water coming thru the fan vents was absolutely unacceptable. It sounds like yours is just as bad as mine was and if so.. then the issue will be many things. Unfortunately, only one of them being the pollen filter cover.

Im guessing that your lower windshield grille foam is gone or nearly gone. There should be a foam insert, bottom center of the windshield, that mine never had when I purchased it.. The purpose of this foam is to keep out leaves and crap from clogging the drains that sit right next to the interior fan housing that holds the pollen filter. I found mine just perfectly clogging the drains on each side mixed in with mud, pine needles, leaves etc.. Once this happens it creates a big pool of water that sloshes around and into the housing for the interior fans while driving. There is also a nice gasket on the bottom of the filter housing but it was old after 20 years and starting to crack. This combination is the main entry point.

I then cleared the drains. Took off the housing and gasket; and was very generous with the silicone. Also, I bought foam sheet and added them in the grille like factory. (In the future I will use a metal mesh screen since mine is starting to fall apart again.)

After this..The waterfall feature was turned off.

Until......it still had a slow drip...

So once again off with the wipers, and lower windshield cover. But this time..I took off the black metal cover that hangs directly over the fan housing body to investigate further. Under it you will probably find a very deteriorated foam gasket. And this is where the slow drip comes from. The failed foam gasket would wick the water under the plate and drip straight down into the fans. Both sides, exact same problem.

Then I went crazy with the silicone! Completely covered the bottom part of the black cover plate to the body of the car.. Even put a dab in every single bolt and screw hole while reassembling. Its been about 4 years now and not a drop.

Good Luck