Vanning.com logo
 
Boxdin
Site Navigation


Advertisements
Recent Posts
g20 engine upgrade options?
by Lettercraft. October 22nd 2017 8:11 pm
Van Damn! My first van build thread
by Kylescore. October 22nd 2017 6:04 pm
Dr. Bob's Jokes Thread
by frscke1. October 22nd 2017 4:50 pm
G10 sway bars?
by shaggy. October 22nd 2017 4:48 pm
89 GMC,Chevy rear door hinge pins
by frscke1. October 22nd 2017 12:10 pm
1971 Chevy Sportvan- Flooded Carb Issue
by discountpirate. October 21st 2017 9:58 pm
Responses to haters/uninitiated?
by frscke1. October 21st 2017 8:16 pm
Van related insults
by Vanzig. October 21st 2017 7:29 pm
The Blue turd & The Bastard.
by oldskool73. October 21st 2017 6:36 pm
My 86 Toyota van Bam-ba-Lam
by oldskool73. October 21st 2017 6:34 pm
Featured Links
Vanning.Com is a an authorized Amsoil Dealer


Previous Thread
Next Thread
Print Thread
Rate This Thread
#728026 - September 19th 2017 10:27 pm 84 G20 with low/no heat  
Joined: Sep 2017
Posts: 12
JAGI410 Offline
stranger
JAGI410  Offline
stranger

Joined: Sep 2017
Posts: 12
MN
Winter is coming and I’m new to these older vans. Here’s a weird one. When on “heat” mode, low/no air comes from the vents regardless of fan speed.

-AC blows cold and responds to fan speed
-Vent blows warm and responds to fan speed on “vent” mode
-Defrost works well
-van runs cool on temp gauge (never over 1/4 up)
-heater hoses hot
-heater core replaced/system flushed a year ago (previous owner)
-upper radiator hose cool/empty feeling
-coolant topped off
-new radiator cap
-recent water pump (previous owner)

I’m thinking thermostat, but shouldn’t the vents be blowing air at me in heat mode?


Jason
1984 Chevy G20
#728031 - September 19th 2017 10:39 pm Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Sep 2005
Posts: 8,108
CatFish Offline
carpal tunnel
CatFish  Offline
carpal tunnel

Joined: Sep 2005
Posts: 8,108
Georgia, USA
In "heat" setting you will only get air flow from the floor/under dash openings.
To get warm or hot air from the dash vents you would need to swap to vent and push the temp control to hot.

Is there air flow from the underdash/ floor area in "heat"?

Last edited by CatFish; September 19th 2017 10:41 pm.
#728039 - September 20th 2017 9:11 am Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Sep 2017
Posts: 12
JAGI410 Offline
stranger
JAGI410  Offline
stranger

Joined: Sep 2017
Posts: 12
MN
Thanks for the quick response Catfish! That's helpful to know that air doesn't come from the upper vents in "heat" mode. Yes I believe there is air flow coming from below in heat mode. So now it's just a matter of figuring out why the van runs cold. I will swap the thermostat this weekend.


Jason
1984 Chevy G20
#728043 - September 20th 2017 10:46 am Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Sep 2005
Posts: 8,108
CatFish Offline
carpal tunnel
CatFish  Offline
carpal tunnel

Joined: Sep 2005
Posts: 8,108
Georgia, USA
Hope it helped.
We currently have three GM vans. All of which are "cold natured" as the saying goes. They all seem to take their sweet time warming up from a cold start even with a proper working T-stat.

#728048 - September 20th 2017 11:37 am Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Aug 2001
Posts: 11,325
Reed Offline
Maniac
Reed  Offline
Maniac

Joined: Aug 2001
Posts: 11,325
Fircrest, WA
I know pretty much nothing about Chevy vans or technology, but I have a few generic suggestions. First, if your van has a clutch fan, check if the clutch has failed in the "on" mode and is making the fan spin at all times. This can cool the radiator fluid too much and make warmup times longer. Second, reverse flush your heater core. You will be surprised the gunk that can build up in there. Third, verify the temperature blend door is moving properly and the seals around the door are in good condition.


Windows- they're what make a van worth owning!
#728097 - September 21st 2017 9:09 pm Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Sep 2017
Posts: 12
JAGI410 Offline
stranger
JAGI410  Offline
stranger

Joined: Sep 2017
Posts: 12
MN
Good suggestion on the fan clutch, but that is not the case here. I drove it a little longer today and the upper radiator hose got hot, so the thermostat is certainly working. Warm air comes out strong from lower vents, but it’s not as hot as every other car I’ve owned. Perhaps it really is just cold blooded. A Cardboard radiator blocker might be necessary to survive a MN winter!


Jason
1984 Chevy G20
#728173 - September 24th 2017 11:19 pm Re: 84 G20 with low/no heat [Re: JAGI410]  
Joined: Sep 2016
Posts: 19
Vanereal_Disease Offline
stranger
Vanereal_Disease  Offline
stranger

Joined: Sep 2016
Posts: 19
Illinois
Maybe an air bubble in the heater core?

Are both hoses to the heater core hot?

Or.... get one of those fancy laser temperature things and make sure the whole core is getting hot and not just one path through it.


Moderated by  Astro 

Donate


Upcoming Events
discovery
Instagram Feed
Who's Online Now
0 registered members (), 0 guests, and 6 spiders.
Key: Admin, Global Mod, Mod
Newest Members
jumpncrash, cbrrudy, BillC, HazelUK, PicPerfAdventure
10006 Registered Users
Top Posters(30 Days)
frscke1 90
Reed 44
Turnkey 38
CatFish 29
Wedgy 23
Forum Statistics
Forums69
Topics32,926
Posts502,744
Members10,007
Most Online177
May 8th, 2013
Tinfoil Security

Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.071s Queries: 15 (0.010s) Memory: 5.7884 MB (Peak: 6.0508 MB) Zlib enabled. Server Time: 2017-10-23 04:18:04 UTC