No heat in my 87 911 - help please
03-05-2013, 12:47 PM
#1
Track Day
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No heat in my 87 911 - help please
The fan in the engine compartment is working, and both front fans are working ( although the right one is getting pretty weak), and the auto heat switch (between the seats) seems to be controlling the fans ok, BUT I GET NO HEAT OUT OF THE VENTS. Whatsup with that?
03-05-2013, 12:57 PM
#2
Drifting
Did it ever come out of the front vents? Only AC comes out of my front vents. I believe this is true for all auto heat optioned cars. Heat comes from the floor vents and will come out of your top defroster and the 2 little defroster vents that are near the windows.
03-05-2013, 01:22 PM
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Drifting
03-05-2013, 02:07 PM
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Team Owner
i wonder what ever happened to Ian . he used to come to our Toronto meets quite regularly and then dissapeared off of Rennlist and our get togethers .. oops sorry abotu the O/T but he made the pic along with a lot of other great resources we use.
03-05-2013, 02:13 PM
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Track Day
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The heater was working just fine on a trip this weekend. I got back in the car to come home, and suddenly no heat. The fuse was blown on the front left blower, so I replaced that, and I put lubicant on the front right. Both blowers are working, just no heat coming out. As mentioned previously, the blower in the engine compartment is working. Something is obviously blocking the heat between the engine and the cockpit.
03-05-2013, 02:18 PM
#7
Team Owner
i think the autoheat is attached to the cable that opens the gates on the heater boxes back in the engine bay does it not ? i wonder if the cable is broken or the control box isnt working.
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03-05-2013, 02:53 PM
#8
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I have both the "101 Projects for your Porsche 911" by Dempsey and "Atomotive Repair Manual 911" by Haynes. Both of these are useless for neither deals with the new autoheat control unit. They do have a thorough explanation of the older units which have the two manual levers between the seats. One explains that these levers control flappers in the heat exchangers mounted underneath the car. I now suspect that these units are not opening to allow the air to flow. Does anyone know how these are controlled with the autoheat switch, and how would you check/repair it?
03-05-2013, 03:37 PM
#9
Rennlist Member
There is a connecting rod about 4-5 inches long with ball sockets on each end. I'll bet one or both fell off or are broken. Pelican has them (PN 999-168-021-40M100) for $2.25 ea. Those are plastic or Teflon and get brittle over the years and crumble to nothing. That's what happened to me.
03-05-2013, 05:31 PM
#10
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Location: Manhattan Beach, California. Retired Engineer 1986 Targa-Factory Delivery Original Owner
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Auto Heat Servo Control Rod.
There is a connecting rod about 4-5 inches long with ball sockets on each end. I'll bet one or both fell off or are broken. Pelican has them (PN 999-168-021-40M100) for $2.25 ea. Those are plastic or Teflon and get brittle over the years and crumble to nothing. That's what happened to me.
03-05-2013, 11:23 PM
#11
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There is a little motor under the control that actuates the cables connected to the flapper boxes. The Bently manual has a good trouble shooting guide I believe. Mine was the opposite, it wouldn't turn off. Turned out to be rusted flapper boxes not fully closing.
