Fresh Air Blower, Sound, but no fury Options

[rwilner]

When I put both black levers to the right, I can hear the fresh air fan blowing but the airflow out the defrost and dash vents is quite minimal. The fan does work on all 3 speeds.

Similarly -- I just reattached all my heat, and even with the booster fan going in the engine compartment, there is just not much airflow. The engine compartment hose and the flapper --> firewall hose are new, the HX's are SSIs in good shape as is the rest of the engine compartment plumbing.

What level of airflow should I expect? What should i check or refurbish to get better CFMs?

[PanelBilly]

Take a close look at the paper tubes that the air flow in and see if there's holes. Check the ones behind the speakers too.

[rwilner]

Take a close look at the paper tubes that the air flow in and see if there's holes. Check the ones behind the speakers too.

Yeah -- they seem ok but they sure are old and crappy.

Does anyone know the ID of the required tubing?

Has anyone had luck sourcing it at a FLAPS or hardware store? I'm getting tired of mailordering parts from CA every week.

[rhodyguy]

where do you have the bottom lever positioned?

[rwilner]

where do you have the bottom lever positioned?

That (red) lever should only effect the fresh air flow, not the heat air flow, correct?

When i'm trying to get heat out of the dash, my config is:
top lever -- full left
middle lever -- full right
bottom lever -- full right
floor lever -- up

Whem i'm tring to get fresh air out of the dash (not heated), my config is:
top lever -- full right (the fresh air fan is on)
middle lever -- full right
bottom lever -- full right (although i don't think this matters)
floor lever -- down

I checked, and the plastic wheels that open the dash vents are in the open position.

[Tom_T]

I agree Rich, if you've verified that your fans & flappers front & rear are all working, then you've got an airflow leak at hoses &/or connectors in 1 or more places. Check them all by removing & inspecting the hoses by pulling the spiral springs apart, cuz they'll cover-up except when "losing air" under pressure. Since both fresh & heat are affected, I'd start with the ones in the cockpit/dash area & behind the fuel tank at the fresh air box to dash.

There's also an outside chance that the hose(s) in the longs could be broken or come loose - esp. if any work was done to the longs &/or jack tubes/supports.

Fresh & heated airflow should be good at even low fan speeds to wherever you direct it.

BTW - the dash controls allow you to put cool fresh air on your face with heat at your feet, which I always loved - esp. when driving late at night when the hot air in the face would make me drowsy. It always kept my toasty with heat even when sub-zero in the mountains out west here on skiing trips!

FYI - when you order from Perf. Products/Automotion/Ecklers they're shipping from Titusville FL now (since Jan.) & they carry most of the hoses in both OE paper & upgraded materials (loprene, etc.), & the ones behind the speakers can be adapted from the engine compartment ones just by cutting to length (same diam. IIRC) if they don't carry specific part nos. for the long to dash hoses.

Look at all this extra work this way - more time to expand your "cuss-cabulary"! (IMG:style_emoticons/default/biggrin.gif)

[rwilner]

I agree Rich, if you've verified that your fans & flappers front & rear are all working,

I haven't verified the front flappers, although i hear some movement / squeaking of valves when i move the levers. Where are the front ones located?

It's probably best for me to just replace the existing hoses, as it sure can't hurt...

[burton73]

I just rebuild the air box flapper box in a super clean no rust Ca. Car but the rubber was dried out in the air box and gone. Un like the air box in my 6 that was still soft and perfect. Have you looked at the flappers? If you air box has a gap in the fan to the body it will not work good.

Bob B

[Drums66]

Take a close look at the paper tubes that the air flow in and see if there's holes. Check the ones behind the speakers too.

Yeah -- they seem ok but they sure are old and crappy.

Does anyone know the ID of the required tubing?

Has anyone had luck sourcing it at a FLAPS or hardware store? I'm getting tired of mailordering parts from CA every week.

...Don't forget V-dub shops for that kind of thing!
(IMG:style_emoticons/default/bye1.gif) no #'s

[McMark]

Our fresh air boxes like to collect leaves, acorns, mice, and other fun stuff. If you want it working nice, you'll need to pull it out and rebuild it. Mikey914 sells new seals for it as well.

The levers work as follows:
Top Lever - Fresh air 'intensity'
Middle Lever - Fresh air location (feet vs dash)
Bottom Lever - Hot air location (defrost vs feet)
Floor Lever - Hot air 'intensity'

[rwilner]

I'm going to buy some of this tubing -- it has the same ID as the crappy paper hose, is rated to 200 deg F, and is $0.50/ft.

Thoughts on that?

[McMark]

Get this 60mm paper tubing. It's OE style.

[rwilner]

The levers work as follows:
Top Lever - Fresh air 'intensity'
Middle Lever - Fresh air location (feet vs dash)
Bottom Lever - Hot air location (defrost vs feet)
Floor Lever - Hot air 'intensity'

Mark
In the "non-feet" setting for the hot air, will it only come out of the defroster and NOT out of the dash vents?

[jim_hoyland]

Be sure nothing has fallen into the windshield airvents; mine had accumulated a dozen parking ticket stubs. May not be easy to see, but a wire with a hook on the end will find most of them. If there's just one or two, you can hear them vibrate when the fan is set to high and your driving at 50 - 60... (IMG:style_emoticons/default/smile.gif)

[rwilner]

ok, an update:

Did some investigating and the passenger side blower is kicking butt, it's just the drivers side that is weak.

I took the hose off the drivers side at the blower, and it seemed strong.

When I put the heat on, the red dashboard lever did not seem to effect the heat airflow direction on the driver's side -- it seemed more or less evenly split between the foot and dash.

So the symptoms:

- weak flow on driver's side from fresh air blower -- pass side is strong
- flow is fairly weak on driver's side from heat
- red lever doesn't effect airflow

Any ideas? is it likely mechanical adjustment of the control cables? Is my driver's side front trunk flapper NFG?

[McMark]

Red lever has nothing to do with the fresh air blower.

I looked at the air flow system again to refresh myself. Here's the important points:

1. The dash vents are a 'branch' off the defrost vents. So anytime you're on 'defrost' you're also blowing out the side vents. This is something I had never considered. You'll get better windshield defrosting if you shut the side vents closed with the little lever.

2. The fresh air location lever (middle) and the hot air location lever (bottom, red) both work the same way. All the way to the left directs the air out the bottom. All the way to the right directs air out the defrost vent (see #1).

3. Pressing the floor lever down is supposed to shut off hot air completely. Moving the top dash lever all the way left is supposed to shut off fresh air completely.

4. If you're getting unequal flow between the left and right vents, you need to check the hoses and boxes for obstructions. You also need to confirm that your flapper boxes are opening fully at the exhaust system. And that your fresh air box valves are opening correctly (pull the paper tubes and look inside).

[rwilner]

Red lever has nothing to do with the fresh air blower.

yep, I get that.

I looked at the air flow system again to refresh myself. Here's the important points:

1. The dash vents are a 'branch' off the defrost vents. So anytime you're on 'defrost' you're also blowing out the side vents. This is something I had never considered. You'll get better windshield defrosting if you shut the side vents closed with the little lever.

my car doesn't have a little lever, it has a wheel under the vent outlet, but it definitely operates as you describe.

2. The fresh air location lever (middle) and the hot air location lever (bottom, red) both work the same way. All the way to the left directs the air out the bottom. All the way to the right directs air out the defrost vent (see #1).

Yep -- on my car, this red lever does nothing to effect hot air flow direction. I checked and the cable is connected to the front-trunk flapper and seems to be moving the articulating arm.

3. Pressing the floor lever down is supposed to shut off hot air completely. Moving the top dash lever all the way left is supposed to shut off fresh air completely.

these both work as described in my car.

4. If you're getting unequal flow between the left and right vents, you need to check the hoses and boxes for obstructions. You also need to confirm that your flapper boxes are opening fully at the exhaust system. And that your fresh air box valves are opening correctly (pull the paper tubes and look inside).

At this point i'm suspecting the tubes because the flappers seem to be working. I will pull it apart over the long weekend and investigate.

Mark -- is there any advantage to the OE tubing other than that it's OE? I'd prefer to use the more flexible, durable, and cheaper nylon tubing.

[ChrisFoley]

Rich, the McMaster link you provided is for a 5/16" od tube. That won't work too well.
AFAIK McMaster has only one product that's suitable to replace those 60mm id paper tubes. I bought some "Blo-R-Vac" rubber hose from them in the past that works good. Its almost $4/ft. though.

[rwilner]

Rich, the McMaster link you provided is for a 5/16" od tube. That won't work too well.
AFAIK McMaster has only one product that's suitable to replace those 60mm id paper tubes. I bought some "Blo-R-Vac" rubber hose from them in the past that works good. Its almost $4/ft. though.

yep -- turns out .232" is not equal to 2.32"!! that's what I get for looking up parts quickly in-between meetings...

$4/ft is way better than $17.50/ft for this stuff.

[rwilner]

Rich, the McMaster link you provided is for a 5/16" od tube. That won't work too well.
AFAIK McMaster has only one product that's suitable to replace those 60mm id paper tubes. I bought some "Blo-R-Vac" rubber hose from them in the past that works good. Its almost $4/ft. though.

yep -- turns out .232" is not equal to 2.32"!! that's what I get for looking up parts quickly in-between meetings...

$4/ft is way better than $17.50/ft for this stuff.

For anyone interested --
here's the blower hose at mcmaster, part # 53335K12 -- it's about $20 for 5 feet (they only sell in 5 ft increments), I think is significantly more than needed for the whole car.