Welcome all 928 forum refugees!
User avatar
By Shifted
#12012
My recirculation flap actuator is leaking very badly. Or, more likely, the vaccum hose isn't connected to it. It holds zero vacuum. I've traced the vacuum line all the way to the hole under the blower fan and the line is intact and the line itself holds vacuum fine.

From what I've been able to determine, the entire recirculation box has to be removed from the dash in order to access the actuator. But, I've never had the blower motor off before. With the blower removed, is the actuator diaphragm accessible enough to verify the vacuum host connection and reconnect it if it's disconnected?
User avatar
By Landseer
#12037
It's been a while, but as I recall removing the blower motor does not provide access. The box should com out, and it isnt that difficult to do, and I think blower motor is also removed or loosened in that process. Am needing to address blower motor removal my brown car this weekend, am glad to work project in virtual tandem with you if you want.

Used to be that removing blower box was an almost mandatory activity when bringing home another 928, so to reseal box to body and stop leaking water.
User avatar
By worf
#12097
Shifted wrote: Wed Aug 26, 2020 10:59 am My recirculation flap actuator is leaking very badly. Or, more likely, the vaccum hose isn't connected to it. It holds zero vacuum. I've traced the vacuum line all the way to the hole under the blower fan and the line is intact and the line itself holds vacuum fine.
So, the flexible silicon line from the firewall plenum that disappears into the recirc box does not hold vacuum?

But, the blue plastic line that connects to the silicon line and disappears into the dash does hold vacuum?
Shifted wrote: Wed Aug 26, 2020 10:59 am From what I've been able to determine, the entire recirculation box has to be removed from the dash in order to access the actuator.
Correct. If the answer to the first question us yes, then the only way to remedy is to remove the recirc box. You cannot get to the actuator or the silicon hose connection with the box installed. You *may* be able to access the actuator and connection by partially withdrawing the recirc box into the passenger compartment. But, I don't see utility in that because it's not too much more effort to get the box out completely so as to do a good job of cleaning and replacing the strip caulk used to seal the box to the metal surround. (You will hate yourself if after re-installation you do a water test and see water dripping onto the CE panel.)
Shifted wrote: Wed Aug 26, 2020 10:59 am But, I've never had the blower motor off before. With the blower removed, is the actuator diaphragm accessible enough to verify the vacuum host connection and reconnect it if it's disconnected?
No. Box as to come out at least partially.

IIRC, Sean removes the blower and box as a single unit by dropping it into the passenger compartment. I tried that once and it didn't work exactly that way for me.

I usually remove the blower from above and then the recirc box from below. This makes WYIT stuff easier. Specifically, removing debris from the evaporator, recirc box, drains, and plenum around the area. And cleaning of those areas.

If you want to try Sean's method I'll let him expound on it.

If you want to remove from above or if Sean's method doesn't work for you then post back.
User avatar
By SeanR
#12110
Nah, you have to unbolt the blower first. One screw/bolt just under the lip of the coupler going to the evaporator. One screw/bolt just under the hood hinge. One long screw/bolt on the underside of the airbox inside the car. That one always stumps people. Once the blower motor is loose you go inside, pull the glove box, pull the CE panel wood covers, unbolt the CE panel at the lower 10mm bolts holding it to the floor. Got about 10-12 bolts holding it in place along with the goo used as a sealant so get a paint scraper or like took to assist in prying the box down. Go outside and use your hand to push the box down some, go back in and repeat that a few times and it will come out.

Doubt any of that made sense but it is my mind typing it out.
User avatar
By Shifted
#12114
Worf, correct. The line checks out fine up to the rubber union under the plastic cover under the hood and behind the firewall. I can trace the line from there to the hole under the blower motor using an endoscope, and it is intact and visually looks ok. However, that section of the line holds no vacuum whatsoever. Given the other issues that I've found on the car, it's likely that it's just not hooked up.

Thanks for the input and confirmation of the lack of access with the blower out.

I need to replace the hood pad anyway, so it seems like a good time to do everything all at once. Pull the hood, pull the blower motor, pull the recirculation box, clean the evaporator, replace the blower resistor pack (mine works, but might as well put a new one in), etc. I'll be sure to seal the flap properly before re-installation. Thanks for the tip.

Worf, I think that I have a pretty good handle on the process, but if you have a prepared guide that you are willing to share, or a link, by all means!

Sean, that's a really good tip on removal as a unit. I will give it a shot just to see how it works for me. What's the advantage to that versus pulling the blower out of the top first?

Landseer, I would love to do this virtually with you, but I'm going to put this off until the fall. For now, I jammed the recirculation door closed so that I can get proper A/C without sucking hot air from the engine on these 95 degree days. Between that and my bypasses of leaks at the solenoid bank, I've got working heat and A/C. The replacement solenoids should be here in a couple more weeks.

I'm really sorry to hear that you're no longer close to me. I was looking forward to having you over to use the lift. But, I'm very glad to hear how well things are going for you!
User avatar
By worf
#12118
SeanR wrote: Wed Aug 26, 2020 3:20 pm Nah, you have to unbolt the blower first.
K. Maybe it's Stan that says he does it that way.

I dimly recall that the one time I tried it that way, there was no way to get the blower out from below.

I agree completely with the rest of your description. On the airbag cars glove box removal adds more 'fun' to this job.

And of course: *always* always always do a water test when everything's back together.
User avatar
By SeanR
#12121
Sure twastn't me. Can't see how that's possible or why someone would want to do it that way. I mean, I suppose one could skip taking out three small bolts and make things much harder, but not what I want to do.
User avatar
By worf
#12124
Shifted wrote: Wed Aug 26, 2020 3:27 pm Given the other issues that I've found on the car, it's likely that it's just not hooked up.
Most likely the rubber diaphragm is cracked. From, just a few minutes ago, looking at a loose recirc box I have, it's not easy for the silicon line to detach from the actuator even if you try.
Shifted wrote: Wed Aug 26, 2020 3:27 pm I need to replace the hood pad anyway, so it seems like a good time to do everything all at once. Pull the hood, pull the blower motor, pull the recirculation box, clean the evaporator, replace the blower resistor pack (mine works, but might as well put a new one in), etc. I'll be sure to seal the flap properly before re-installation. Thanks for the tip.

Worf, I think that I have a pretty good handle on the process, but if you have a prepared guide that you are willing to share, or a link, by all means!
If you are pulling the hood, the only other thing you may need to do is to remove the hex-head screw that fastens the corner of the windshield cowl to the chassis. (You'll see when you get there.) That will allow the cowl to move 'up' just enough to wiggle the blower out. Some 928s need that some don't; 928s aren't built to modern day tolerances.
User avatar
By worf
#12126
SeanR wrote: Wed Aug 26, 2020 3:35 pm Sure twastn't me. Can't see how that's possible or why someone would want to do it that way. I mean, I suppose one could skip taking out three small bolts and make things much harder, but not what I want to do.
Ja. Didn't make sense to me but I tried it anyway :) Never again.
User avatar
By Shifted
#12132
It's possible that the diaphragm is cracked. However, this car was taken completely apart at one point, and things were put back together in interesting ways. Lots of new parts used. Lots of non-OEM parts used. And lots of things not connected properly, or at all, and...well, you get the idea. Given that all of the other actuators don't leak at all, not even a little, and they were supposedly all replaced with new based on the previous owner's records, and based on all of the other things that I've found on the car, my money is on them putting a new one in but forgetting to hook it up. Pulling vacuum on the recirculation actuator is like pulling vacuum on an open hose. There is absolutely no build up whatsoever. If it's connected and cracked, it's a very bad crack about the size of the inner diameter of the hose :) Only one way to be sure what the problem is...take it apart!

In my recent work on the instrument cluster and HVAC, I discovered that the 14 pin connector has wires that don't match the OEM wire colors at all, but is in an oem style harness sleeve, and spliced into a "normal" harness under the A/C compressor. I'm guessing that they got the 14 pin end of the harness from some other car and just spliced it in. Is there another Porsche with a 14 pin connector and different colored wires that they could have used? I don't know. But, it's shoddy work and starting to fail. It looks great from the outside the way that they did it up at the connector, but once you pull the cap off of the back, or check the wire colors, or trace it to the splice, you see how incorrect and poorly done it is.

So, yes. Sean will have to build yet another FoE harness. Whenever I get around to replacing it later this year.
User avatar
By Shifted
#12133
SeanR wrote: Wed Aug 26, 2020 3:35 pm Sure twastn't me. Can't see how that's possible or why someone would want to do it that way. I mean, I suppose one could skip taking out three small bolts and make things much harder, but not what I want to do.
I misunderstood your guidance. But I understand now. Don't even try to push the blower down with the recirculation box. Got it! I was willing to give it a shot if you said it worked, but it did seem like a strange way to go about it :)
User avatar
By SeanR
#12134
Shifted wrote: Wed Aug 26, 2020 3:50 pm
So, yes. Sean will have to build yet another FoE harness. Whenever I get around to replacing it later this year.
That I can do man, just let me know. So far this is the first week in several months that I've not made any. Did 5 last week so I ain't complaining.
User avatar
By SeanR
#12148
I love making the FoE's, I actually find it relaxing, even the double harnesses of the early cars. I don't have to focus on anything else or do any trouble shooting. Since Rog put them on his site they have been selling like mad.
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User avatar
By worf
#12166
Shifted wrote: Wed Aug 26, 2020 3:50 pm However, this car was taken completely apart at one point, and things were put back together in interesting ways.
Ah! I'm getting the picture now. Ok. I thought we were dealing with a run-of-the-mill fixed-when-broken 928.

If it's been "thoroughly touched" then all bets are off.

Of of the 928s I have here right now is like that: thoroughly touched and some really stupid shit I've found. (3 of 8 spark plugs finger tight, at best, etc.)
User avatar
By Shifted
#12360
Here's a fun one that you wouldn't expect or even find unless you start taking things apart...

I pulled the oil pressure sender adapter since I figured it couldn't hurt to replace the springs and regulator while I was doing the pressure sender anyway. I found that the previous shop had removed the springs and stacked some washers in there with the regulator.
User avatar
By worf
#12363
These anecdotes (edit: from all of us) probably deserve their own thread.
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