engine compartment blower

With winter rapidly approaching I've been trying to get the heating system on line. I don't think the fan in the engine compartment is working and was wondering if its easily accessible and if you can get any heat at all without it.

I just got done rebuilding my blower. I'm at work now, but I think you have e-mailed me, perhaps on the injector o-ring thing. Anyway, don't hesitate to ask about the engine compartment blower motor, as I've found a way to fix them.

And yes, heat still happens without the blower motor. In fact, the blower motor helps ony a little. Hot air volume is still mostly a matter of engine (main fan) speed.

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'83 SC

Superman,

Where did you get the parts (bearings etc) for the heater motor? Can you get parts for this specific motor or did you match parts out of another brand motor?

Thx,

JoeA

I far as I know the heater blower is just for outside fresh air. You get maximum heating with the blower off.

You should check the fuse first, before rebuilding.

The fan that blows fresh air from the front hood sccop is one thing. The fan that blows air from the engine shroud to the heater boxes, etc, is another. One you can control the velocity on (the front one). One you can't. I also believe earlier 911s didn't have one in the back, but relied on air movement from the main engine fan. Some lightweight variants also settled for the velocity generated by the main engine fan.

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Jack Olsen
1973 911 T (3.6) sunroof coupe

Again, there should be enough hot air to get heat without the blower. Check hoses.

The heater blower motor busing is not designed to be replaced. It is a crazy swivel thing that you have to ream out in order to fit a bronze bushing, if you have this patience. The blower motor shaft is a standard 3/8" I believe and bronze bushings are plentiful. the brushes are for a military HumVee alternator.

The blower helps a bit but creates no hurricanes. In fact, the main engine fan does most of the work. With a warm engine at 3500 rpm, you should have heat. Check hoses.

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'83 SC

Super is right, as long as you are moving down the road you will get plenty of heat without the motor. I say check the fuse and fuseholder. My fuse looked good, checked good. The fuseholder was corroded. Cleaned it up and the blower works fine.

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Robert Stoll
83 SC
83 944

Is there an aftermarket in-line fan that would do the job better -- i.e., move more air? It seems like it could be used back by the engine (in place of the Porsche blower), or up under the dash. Has anyone tried this?

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Jack Olsen
1973 911 T (3.6) sunroof coupe

I'm interested in the location of the heater hoses. I've checked the blower motor and fuses and mine seem fine, and I also checked that the levers aren't stuck and they aren't, but I *still* don't get decent heat volume. A day or so ago I noticed a bit of smoke coming from my vents, which leads me to suspect my hoses are bad. What I've seen so far looks fine - where are all the places I should look?

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Emanuel Brown
1983 911 SC Targa
http://home.att.net/~epbrown01/91183.jpg

I've heard of someone installing a Jap motor in place of the $200 Bosch unit, the motor was pretty reasonable and worked better but thats all I know,

I replaced my blower with a smaller 914 one from a junk yard and it seems to work the same, these motors are always on so they seem to wear out fast due to the heat from the engine

I believe the 86 and later 911's have extra inline fans in the left and right footwells that could be installed in earlier cars. They look just like the ones JC Whitney sells for VW's that need help. As far as heat volume, my 72 that has no engine blower fan defrosts better than my friends 76 that has a nonfuntioning fan. It seems that with all that extra plumbing for the fan, you need the fan. The main engine cooling fan has to overcome more twists and bends in the more complicated later setup. I think the only time this is a factor really, is when defrosting the windshield. The footwell openings are a lot more free flowing than the defrost ducts. My friends 76 heated my feet fine, but took 5 times longer to defrost the windshield than my early car did.

Those self center bushings one of you were talking about are impossible to find. I disassembled my motor and removed bushings then machined some new ones on my lathe. Its actually quite easy to do and the motor works great now. Someone told me a peticular VW model uses the same motor and can be bought through VW much cheaper, now if I can just remember the model? Matt

Try and remember that VW number, as folks have problems with these motors. I reamed my bushing with a rotary tool and epoxied a regular bronze bushing in. The replacement original bushings are not sold.

I'd say keeping it lubed is the best advice, overall. Pretty hearty motor, except for that bushing.

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'83 SC

Superman and others - I would appreciate any info on alternate replacement and/or repair of the air handling blowers. Seems that all blowers on my 87 have gone south at once - (bearing squeal when cold and what seems to be endplay rattle) Need to replace engine compartment, r/l foot-well, AC evap, and AC cond blowers. While I'm asking - has anyone found a AC evap blower that will move more air with less noise? Thanks

On engine comp. blowers,mine quit,tried everything, ready to buy new blower, finally checked voltage across fuse, nothing. Fuse was good but corroded on ends, cleaned ends everything worked fine. Blowers are turned on buy a small switch at the heater levers between the seats, pull up the boot to see ,clean them to. see Bob Tindels tech artical on this website regarding these switches, i don't remember the title. good luck ...jerry m

After trying in vain to rebuild my malfunctioning heater motor, I gave up and bought a new one. I've also replaced some of the hoses.
Now it turns out that most of the hot air escapes through the rust holes in the heat exchangers...
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82 SC

I've owned a 74 911S with no engine bay heater blower. Not a great setup. A '80 911SC with the engine bay blower, AWESOME heat (SSI heat exchangers!) And my current winter car is an '84 Carrera that has 3 blower motors: Engine bay, Left footwell, Right footwell.

All of the blower motors I've had have failed, apparently due to neglect. If the bearings seize, the motor will burn up. If the brushes are never replaced, it can short and burn up. My '84 footwell blowers are melted/charred lumps of crap, completely un-repairable. Same thing with the A/C condensor blower up front.

I have to believe these blowers are inferior to, say, a Honda or Toyota...those cars go the junkyard with 200k on them long before the blowers stop working!

If anyone can help find replacement parts or motors, or even alternatives, PLEASE POST! I can replace brushes easily, but my Carrera blowers are too far gone. The blower housings are fine, though.

I've agonized over the heater blower. Managed to get anothyer bushing in there (front bushings wear and this kills the motor. Brushes can be replaced. The motor is making noise again. I unplugged it and it really makes NO DIFFERENCE. I get good hear with the motor unplugged. Don't really need it, I've decided.

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'83 SC

Hey Warren, or anyone else who might know. About this blower stuff. I just found the blowers in the kick panels. After I bought the 89 911 I found out the blower in the engine compartment was unpluged. Well good reason, the bearings are out around the fwd shaft. Tell me about the other blowers in the kick panels. Should they work independantly from the blower in the engine compartment? Does the plug from the engine compartment have to be closed to allow the kick panels blowers to work? I dont care about replaceing the motor in the back right now, but If I could get the kick panels to work great. If not, I get good enough heat with out the aft blower. All of your knowledge in this heater system and blowers could be a great help.

Mike Miller
89 911