Cabin Air-Intake Filters (now with pictures)

[MJL944]

My 1989 S2 has some sort of (pollen/charcoal?) filters behind the metal grills at either end of the Cabin Air-Intake/Heater Blower Unit that sits under the plastic cover behind the engine. The driver's side 'pollen filter' sits behind the metal grill that has the external air temp sensor prong in front of it.

Both of these filters are/were white but they look rather dirty now - especially the passenger side one - and I'd like to remove to clean or remove entirely.

I can unclip the top of the driver's side grill easily but the bottom clip is reluctant to let go and I don't want to force the grill off in case I damage the air temp sensor prong which is already wobbly on its mount. The passenger side metal grill doesn't appear to be designed to pop off like the driver's side grill at all.

I thought the S2 didn't have cabin air-intake filters but the SH with my car shows a previous owner was twice charged by an established Indy in South London for new 'pollen/charcoal filters' - most recently in 2008, which is presumably how old my 'filters' are.

I've seen some posts on USA-based Porsche forums mention fitting home-made filters behind these intake grills - often using those perfumed tumble dryer sheets - but nothing saying there's an 'official' filter for these intakes.

My fan blower seems to work OK but I'd like to clean or replace the filters so any advice - including how to get at them - would be appreciated.
Thanks.

 

[George Elliott]

Mark, I am not certain of the metal grilles you refer to, and no 944 I have ever seen had a factory fit Cabin Filter. Your description sounds like a Pollen filter has been fitted under the scuttle where the cabin fresh air supply is taken in. Not a bad idea as the 944 was out and about when Pug 406's and the PSA 1.9 diesel was popular, and in those days it was sometimes difficult to breath on the motorways. [] If you google HEPA Filter Material (High Efficiency Particle Air) filter you will find this super low density material is available. I suggest you just need some material which you can cut out using the existing as a pattern and replace it. Images would help if you have any good luck George 944t

 

[MJL944]

Thanks very much George. You're correct on two fronts: Images would have been helpful - so I've taken and attached some below - and the 'pollen filters' are indeed under the scuttle in the fresh air supply intakes. I think you're also correct in that some sort of HEPA material has been used by the Indy in question to improvise a pollen filter. I'll investigate the material - thanks for the information. Driver's side intake grill with the grubby 'pollen filter' lurking behind it:

Passenger side with an even grubbier 'filter' present:

In real life they're dirtier than they appear in these photos so I want to get them off and cleaned or replaced. Has anyone taken these grills off? Am I right in thinking the temp sensor prong needs to be removed on the driver's side as there seems to be no room otherwise to lever the grill off and away. On the passenger side mine looks as though it is not designed to pop off at all with the clip on top all squashed down to apparently clamp it on. Will I just have to be brave and force it off somehow? In honour of Ken's fastidious rebuild I promise to re-paint these grills nicely before putting them back - if I can get the damn things off!

 

[Hallsy]

Looks like your 944 has been modified or had 968 pollen filters fitted. As far as I know, the 944 never had pollen filters, just a wire mesh in front of the air intakes. Looks like you need to unclip the sensor, and looks to me like the whole grille just clips on - perhaps prising from the tab in the centre at the top would pop them off? Fitting pollen filters to my 944 had crossed my mind, especially when lots of small petals/seeds got drawn in one day, and I spent the next couple of weeks getting bombarded with them whenever I had the fans on!! I think the 968 route is probably best bet pricey, so I'll probably just tie wrap some filter material over the metal grilles that the standard 944 setup has.