warm air - The 1947 - Present Chevrolet & GMC Truck Message Board Network

asickber · 09-07-2007, 10:08 AM

Well I finally got insurance on my 72 and I'm loving it. But, hot air constantly streams out of the AC vents. I have the heater off. I know this might be somewhat normal, but is there a way to stop it without covering any vents?

Also it's a 3/4 ton with a 402 and I filled it up and drove fifty miles and the ol' gas gauge didn't move that much! What kind of mpg can I expect?

JimKshortstep4x4 · 09-07-2007, 07:57 PM

You may want to check the water control valve as it may not be shutting the water flow off.

On your gas mileage, I would guess that you are looking at 10-12 mpg.

Jim

PanelDeland · 09-07-2007, 08:20 PM

Sounds like you just started driving this truck.I would suggest you not trust the fuel guage in it until you know it is working and how it works.Many of these trucks have ground problems at the dash cluster causing the guage not to work.Also the float may have a hole in it or the sending unit may be bad.I just would hate for you to get stranded because of a common problem.
Also there are air doors in the plenum for the heat/AC and they may not be closing.The cable could be causing it or the door may have come loose from it's shaft.These are common problems with the trucks.There are lots of write ups in the FAQ's section that will help you determine which problem you have and how others have fixed it. Good Luck!
BTW Don't be afraid to ask if you have problems following a fix or don't find what you need.

cdowns · 09-07-2007, 08:38 PM

figure getting about 175miles on the first half of the gas gauge about 60 on the second half of the gauge

roughedup72 · 09-07-2007, 09:11 PM

Yep, 1st half last a good ways and youre thinking this is cool, Then after it reaches half tank say goodbye gas.
On the other note, make sure your compressor is turning on or shall I say make sure the clutch is engaging on the compressor.

68C15 · 09-07-2007, 11:05 PM

or wait 4 months. the air will be much cooler then.
may i suggest installing a heater control valve?

gotchevys? · 09-08-2007, 09:05 AM

I have a 70 with a 402 and 3.08 gears. When I drove it from VA to Daytona I got 16-17 mpg

asickber · 09-10-2007, 07:24 PM

Thanks for the replies. I'll be looking into your suggestions.

09-07-2007, 10:08 AM	#1
asickber Registered User Join Date: Nov 2005 Location: Birdseye, IN Posts: 99	warm air Well I finally got insurance on my 72 and I'm loving it. But, hot air constantly streams out of the AC vents. I have the heater off. I know this might be somewhat normal, but is there a way to stop it without covering any vents? Also it's a 3/4 ton with a 402 and I filled it up and drove fifty miles and the ol' gas gauge didn't move that much! What kind of mpg can I expect?

09-07-2007, 07:57 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: warm air You may want to check the water control valve as it may not be shutting the water flow off. On your gas mileage, I would guess that you are looking at 10-12 mpg. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

09-07-2007, 08:20 PM	#3
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,992	Re: warm air Sounds like you just started driving this truck.I would suggest you not trust the fuel guage in it until you know it is working and how it works.Many of these trucks have ground problems at the dash cluster causing the guage not to work.Also the float may have a hole in it or the sending unit may be bad.I just would hate for you to get stranded because of a common problem. Also there are air doors in the plenum for the heat/AC and they may not be closing.The cable could be causing it or the door may have come loose from it's shaft.These are common problems with the trucks.There are lots of write ups in the FAQ's section that will help you determine which problem you have and how others have fixed it. Good Luck! BTW Don't be afraid to ask if you have problems following a fix or don't find what you need. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

09-07-2007, 08:38 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: warm air figure getting about 175miles on the first half of the gas gauge about 60 on the second half of the gauge __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

09-07-2007, 09:11 PM	#5
roughedup72 Senior Member Join Date: Oct 2005 Location: south carolina Posts: 658	Re: warm air Yep, 1st half last a good ways and youre thinking this is cool, Then after it reaches half tank say goodbye gas. On the other note, make sure your compressor is turning on or shall I say make sure the clutch is engaging on the compressor. __________________ 1972 chevy cheyenne 10,nothing special at the moment,Its a work in progress, Working on the engine, paint and body,engine, paint and body,now its the suspenion, ahh hell I'm about tired of working on it. Maybe it will be a rat rod. Last edited by roughedup72; 09-07-2007 at 09:17 PM.

09-07-2007, 11:05 PM	#6
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: warm air or wait 4 months. the air will be much cooler then. may i suggest installing a heater control valve?

09-08-2007, 09:05 AM	#7
gotchevys? Registered User Join Date: Dec 2006 Location: Virginia Posts: 118	Re: warm air I have a 70 with a 402 and 3.08 gears. When I drove it from VA to Daytona I got 16-17 mpg __________________ www.fatdaddieshotrods.com

09-10-2007, 07:24 PM	#8
asickber Registered User Join Date: Nov 2005 Location: Birdseye, IN Posts: 99	Re: warm air Thanks for the replies. I'll be looking into your suggestions.



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