Interested in perspectives...my '91 C2 Tip is a Daily Driver. Clean, but a show car by no means. Over 7 years of ownership I've put +40k miles on and have no intention of getting a new ride anytime soon). I've done a fair bit of maintenance work on A/C and Heater systems with satisfactory results. The A/C blows cold and I'm comfortable in a Chicago Summer commute, and the Heat is more than ample to keep me warm during a polar vortex. The issue now is that the blowers and fans are constantly wheezing, whistling, squealing, etc. Adjusting the fan speed can usually get them to quiet down, but I'm wondering if it makes sense to go piece by piece replacing blowers, fan boxes, vent tubes, etc - OR does are there full suitcase kits that are simply easier and more straight forward to swap out.

Any experience or thoughts to share?

 

 

It is probably time for new fan motors. These blowers have sintered brass bearings that wear out and start squeaking. The axle eventually seizes and Fuse 1 will blow. Any attempt to oil the bearings will at best produce a burnt oil smell in the cabin, especially when the bearings get hot. Changing them is not easy, but indeed doable. Search on this forum and yo will find. There's reasonable-priced third-party spare parts available, the Dansk/JP Group fans are complete with fan cage.
Wheezing can be due to stuck HVAC servos, the fans try to draw air through closed air flaps. Here's a DIY servo and fan test procedure.

Cheers,
Tore

 

Oh this is a topic I'm familiar with.

It's by far the easiest to replace fans if you pull the gas tank first. I've done it both ways (tank-in and tank-out), and the extra work to pull the tank saves aggravation. I had one seized fan and one squealing, with a fairly clogged evaporator. With those three parts replaced the fan strength is far, far greater than the former equivalent to a dog exhaling.

Short of the CCU and servos, I've replaced/refurbished the entire HVAC in my '91 this year. Even in a Florida summer in a Targa with no tint I can stay comfortable.

 

The failing bearings in the "Squirrel Cages"...a big effort to get to. Yes, the fuel tank needs to come out. You might need another set of hands during some parts of the job. Worth doing though.

Fortunately you can get OEM supplier ones a lot cheaper than the official Porsche parts.

Also, once youv'e got the the whole suitcase out, you'll be doing a lot of 'while you're in there' stuff....like checking the flapper/lever arms work, inspecting and possibly replacing the evaporator, replacing seals on the expansion valve etc...

Other squealy part is the small fan on the back of the CCU. That's an easy fix.

Replacing the 'full-suitcase' surely would be prohibitively expensive and likely unnecessary (?) - unless you really want to move to the less complicated 993 unit? But still...$$$
(https://rennlist.com/forums/964-foru...onversion.html)

 

I've been able to replace the fans without pulling the suitcase. It requires some leverage and squeezing, but very doable - this on a car with a/c. Only an evaporator replacement requires the suitcase to be removed, which is an absurdly annoying job. Not much else in there that ever needs needs replacement, thankfully. The dansk fans push slightly less cfm, but hardly noticeable.

 

There's a lot going on under there. Is there an accepted "club sport" type of minimalist A/C and heat that saves some of the complexity and weight of all this? I've seen the electric AC package but didn't see where that was available for a 964.