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#1 |
Registered User
Join Date: Apr 2009
Location: Normal, IL
Posts: 138
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Luke Warm Air...
It's getting really cold here in Central Illinois, and my heat is barely luke warm. I'm wondering if I need a new heater core?
I put in a 195 degree thermostat, instead of the 180 I was running before, and that didn't make any difference... The temp is running around 210 and I don't have any real heat coming out of the vents!? I don't have any antifreeze leaks, sweet smells, etc...can the core just go bad? What do you guys think? |
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#2 |
Registered User
![]() Join Date: Jan 2009
Location: marion nc
Posts: 588
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Re: Luke Warm Air...
it could be stopped up. check and make sure your coolant level is full.
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69 short fleet 350/350 "under construction" 70 short step 307/3 speed |
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#3 |
Car Knocker
Join Date: May 2001
Location: jefferson,arkansas
Posts: 664
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Re: Luke Warm Air...
Your outside duct work maybe stopped up with leaves and mouse nests. How much air you getting out the floor vent? My truck had a Fred Flintsone floor in it and it would keep you warm after I cleaned out all debris. Granted Im in Arkansas and you in a colder climate.
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68 c-10,91 sportside bed,350 .030 over,4 bolt,10-1 comp,2.05 intake/1.94 exhaust,1.6 Harland Sharp roller rockers,edelbrock rpm cam and intake w/750 carb, 700r4, 3.73 gears,Jacabbs Electronic Igntion w/Accel HEI distributer and super coil. ZR-1 roll pan, filled tailights. Blazer tank. Hidden hitch. 2 1/2" Flowmaster 40's. Parts bought but not installed>> ford 9" posi with disc. CCP front and rear lowering kit 4/5. Cab corners,foor boards,rockers, cab braces, Phatom grill, Painless wiring kit. |
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#4 |
Registered User
Join Date: Nov 2010
Location: Venus, Tx
Posts: 121
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Re: Luke Warm Air...
flush it both ways, then top up the system and try again
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#5 |
Registered User
Join Date: Jun 2010
Location: Upland Ca
Posts: 4,143
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Re: Luke Warm Air...
Do you have a malfuctioning shut off in the engine bay? Check for proper heater hose routing. With the engine up to temp do both heater hoses feel the same temp, are they both hot, is one cooler than the other by the core?
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1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703 |
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#6 |
Registered User
Join Date: Apr 2009
Location: Normal, IL
Posts: 138
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Re: Luke Warm Air...
it's full of coolant
both hoses ar hott! closest to the heater core and I have plenty of air coming out of the vents this must mean that it needs to be flushed...correct? Can I do this with a garden hose, or does it need more pressure than that? |
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#7 |
Registered User
![]() Join Date: Jan 2009
Location: marion nc
Posts: 588
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Re: Luke Warm Air...
i have flushed them with a water hose, just may take "multiple" flushings to get it loosened up. if flushing helps i would replace the core first chance you get.
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69 short fleet 350/350 "under construction" 70 short step 307/3 speed |
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#8 |
huh?
![]() Join Date: May 2000
Location: Washington, Illinois
Posts: 5,692
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Re: Luke Warm Air...
I've run into the same thing before. Barely had heat until I replaced my heater core, it was plugged up badly. You can try flushing it for now, but it would probably be a good idea to replace it in the spring.
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Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay |
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#9 |
Registered User
Join Date: Oct 2007
Location: Spanaway
Posts: 8,451
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Re: Luke Warm Air...
You should also double check that the cable actuator is actually opening the flap door that allows the heat from the core to enter the fan box, i unhooked my cable and listened for the door movement.
from what i have read here on the forums there is a small access door you can open to look inside to see the flap door, but i beleve you may have to remove the glove box liner to access it? I have not done this, just read something about it.. but as also posted above the outside duct work can get clogged up with debree too, this will require removing the cowel so you can get a small vacume hose inside.
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Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's Last edited by swamp rat; 12-01-2010 at 08:42 PM. |
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#10 |
Registered User
Join Date: Aug 2009
Location: St. Paul MN.
Posts: 1,996
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Re: Luke Warm Air...
As said before back flush the heater core a few times with a garden hose should push the blockage through. Heck I had a 08 Buick with 50000 miles on it that the core was plugged it just happens
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Fuzzy |
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#11 |
Registered User
Join Date: Apr 2009
Location: Normal, IL
Posts: 138
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Problem Solved
Went to the local parts store got a section of 5/8 hose (so I could flush by using the wand at the carwash), got some extra coolant (so i could top it off afterwards) and put $2 in at the carwash...did it all in the bay at the carwash and took about 15 minutes from the time I pulled in, until I had hot air again.
Thanks guys, and I'll replace the core in the spring! |
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#12 | |
Registered User
Join Date: Jan 2008
Location: MT
Posts: 85
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Re: Luke Warm Air...
Quote:
Two words, "Silicon Silicate", this was a common additive put into the cheaper antifreezes and tended to completely clog vehicle radiator and heater core passages. I do not know how to remove this type of clogging other than to replace the cores. The older GM (Blue),Glycerol antifreezes were the absolute best over-the-counter antifreezes a person could find,(kind of a shame that GM realized this and the price began to reflect it). I do not know for sure if this is what is aflicting your truck, but I'd suspect it and change out the heater core as soon as you can. (Especially if a couple of flushes and cleaning out the other system areas aren't giving you the results they should). You could flow-test the heater core by removing the hoses and running water through the heater core. If it runs easy, it may not need replacing, if it only barely trickles through, it's new core time. Other things I've done to help harm my trucks is wrapping the heater hoses in neopreme insulation that fits around the hoses,(Ive found these at most home centers. the stuff comes in 4' and 8' lengths with a split down the center with adhesive in the split to stick it together), and blocking off the front of the main radiator's air flow about 40-60%. Another thing to look for is good weather seals on your doors & windows,(lots of drafts from aged weather stripping just defeats any heater. This brings me to the Kick Panel Vent weather seals. If these are cracked or missing, it may be hard to tell if your heater is even working well or not in the winter. My regular driver,(C20), was built to pull horse trailers in temps that match Death Valley,(huge cooling system), which all needed to be compensated for when I moved it to NV, CO and later to MT. I'm still learning about all what can be done with a heating/cooling systems on these trucks. I guess maybe "Seat Warmers" if I move any farther north... ![]() IHTH Michael Last edited by C. M. Wolf; 12-09-2010 at 01:43 AM. |
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#13 |
Registered User
Join Date: Jun 2006
Location: Indiana
Posts: 4,859
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Re: Luke Warm Air...
Hey Slategrove! I see you are from Normal. My brother lives is Bloomington, close to the airport.
Glad you got your heater fixed. It is toooo early for this kind cold stuff! I usually end up blocking part of the radiator off with card board. The plastic kind works best.
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'70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60 |
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