Last Articles

duracell 24f car battery hid temperature color chart check engine code p0306 everstart 58r 3 average cost of tile shower installation honda accord steering rack leaking 1999 honda accord alarm problems rack n pinion cost tsx manual transmission headlight restoration homemade alpine type r 12 wiring bad brake caliper noise toyota highlander hood latch problems 2014 honda civic b1 service home depot krylon fusion 2004 honda civic clutch replacement
Community
Search
Notices

Heater blows warm while driving-Blows cold air at idle!

Reply

Thread Tools
Search this Thread
Old 02-07-2014, 09:02 PM
#1
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
Heater blows warm while driving-Blows cold air at idle!

2007 TL w/104k
I live in Ohio so its cold!
Driving down the road, nice and warm in the car, when I come to stop, it blows cold air.
What I've had done so far.
Timing belt-done at 100k 2013
Tune up at 104k 2013 dealership
Winter of 2013 the issues begin!
11/13 New thermostat, -my acura/Honda mechanic
Same Issue Still
12/13 New thermostat, pressure check, burb. -Dealership
They suggested possible radiator cap and flush heater core. (dealership does not perform heat core flush)
Same Issue Still
1/14 Heater core flush with new thermostat and pressure test -local garage
Same Issue Still
Sometimes when I turn off car it smells like antifreeze and looks like steam coming off the front but no leaks on ground
I don't know what else to do????
(wife isn't too happy either)
lost....help!
bandits31 is offline
Reply With Quote
Old 02-08-2014, 06:44 AM
#2
Registered Member
iTrader: (1)

Join Date: Apr 2007
Location: NJ
Age: 54
Posts: 7,681
Thanked 773 Times in 635 Posts
It's a classic sign of low coolant in the rad, but that seems to have been checked many times, but as there may be a leak, check the coolant level in the rad (not reservoir) when cold. I see that the system was pressure tested a few times, but needs to be done when cold, pumped to @ 18lbs and let sit for a while to see if any drop in pressure. Some small leaks take quite a while to find, but as the pressure drops, pump it back up to 18 lbs and wait.

Might want to check the heater control valve to make certain it's fully opened. Feel the hoses before and after the valve to be certain the valve to firewall hose is as hot. If different, try opening the valve manually, if it can be moved.
You most likely don't have an infrared thermometer to check temps at various locations, but they are very useful for many situations.
Turbonut is online now
Reply With Quote
Old 02-08-2014, 10:18 AM
#3
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
yeah, find the leak and fix it. if there are no visible leaks and the car runs fine and you smell coolant in the engine bay, time for a new rad cap. I had started smelling coolant in my engine bay and noticed greasiness on the rad around the cap. $20 later the problem was solved. The spring in the cap will weaken over time and not allow it to properly seal and thus the smell and no leak. The original cap lasted from November 2001 to May 2013

Last edited by YeuEmMaiMai; 02-08-2014 at 10:21 AM.
YeuEmMaiMai is offline
Reply With Quote
Old 02-08-2014, 12:34 PM
#4
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
I will get a hold of my local acura dealership Monday and ask them to do another pressure check and put a new radiator cap. Will keep you guys informed. thanks a lot!
bandits31 is offline
Reply With Quote
Old 02-08-2014, 04:27 PM
#5
Registered Member
iTrader: (1)

Join Date: Apr 2007
Location: NJ
Age: 54
Posts: 7,681
Thanked 773 Times in 635 Posts
Originally Posted by bandits31 View Post
I will get a hold of my local acura dealership Monday and ask them to do another pressure check and put a new radiator cap. Will keep you guys informed. thanks a lot!
Have then pressure check the radiator cap first, it will be easy for them. Also, if no leak is found when testing, check the tube to reservoir as they can crack at the slip fitting under the cap.
Turbonut is online now
Reply With Quote
The Following User Says Thank You to Turbonut For This Useful Post:
YeuEmMaiMai (02-08-2014)
Old 02-08-2014, 04:38 PM
#6
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
I agree with you in principal but I would just buy the cap as it will cost him more to have it tested.
YeuEmMaiMai is offline
Reply With Quote
Old 02-10-2014, 06:52 PM
#7
Registered Member

Join Date: Mar 2008
Location: boston
Age: 35
Posts: 92
Thanked 1 Time in 1 Post
Having the exact same problem, any update yet???

Thanks, Sam
sam617 is offline
Reply With Quote
Old 02-10-2014, 07:30 PM
#8
Registered Member
iTrader: (1)

Join Date: Apr 2007
Location: NJ
Age: 54
Posts: 7,681
Thanked 773 Times in 635 Posts
Originally Posted by YeuEmMaiMai View Post
I agree with you in principal but I would just buy the cap as it will cost him more to have it tested.
I tend to agree with you, but I would also like to find the offending part first rather than just installing a new cap and waiting to see if the problem has been fixed or not.
Turbonut is online now
Reply With Quote
Old 02-12-2014, 10:06 PM
#9
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
My car finally goes in tomorrow, I requested for them for a pressure check again.
Monday morning I saw a couple drips on my garage floor before I went to work.
I open my hood and I notice something odd.. The reservoir was almost to the top, so I looked at radiator, it was full. This problem is kicking my ass. Feeling frustrated and cold.......
bandits31 is offline
Reply With Quote
Old 02-13-2014, 12:29 AM
#10
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
Are you checking when cold or hot? Should be at the max level when hot and min when cold.

So suck out some of that coolant and bring it to the min mark and then run the car and see if it gets to the max mark when the car is up to temp

The rad cap is supposed to let some coolant out as it expands and then allow the pressure decrease suck it back in when it cools.
YeuEmMaiMai is offline
Reply With Quote
Old 02-14-2014, 03:00 PM
#11
Moderator

Majofo's Avatar

Join Date: Sep 2008
Location: Waffles, BU
Posts: 77,545
Thanked 9,290 Times in 6,831 Posts
+1 check on heater control valve
Majofo is offline
Reply With Quote
Old 02-18-2014, 08:57 PM
#12
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
I'm getting the results tomorrow! cross your finger! I will check with them on pressure test again.
bandits31 is offline
Reply With Quote
Old 02-19-2014, 01:22 PM
#13
Registered Member

Join Date: Mar 2006
Location: Bakersfield
Posts: 20,172
Thanked 1,773 Times in 1,255 Posts
I still can't believe it's not low coolant.

Anyone know if the heater control valve uses an electric motor/solenoid or vacuum (I know it's cable actuated)?

Onto the "weird" stuff, did this happen before the TB install? Just wondering if some how the pump slips at idle. It's a very, very long shot. You would probably have tensioner noise or some other audible warning.

Severely blown headgaskets can cause weird issues (myself and my father have a wall of shame in our garages filled with blown headgaskets so I'm pretty experienced) but it's usually the opposite. Warm at idle and it cavitates the whole system when you give it throttle, killing heater output. You would be losing coolant if this were the case.

Somehow I have a feeling it's going to be coolant level/heater valve related.
I hate cars is offline
Reply With Quote
Old 02-19-2014, 01:38 PM
#14
Banned

Join Date: Aug 2003
Location: North, NJ
Age: 39
Posts: 186
Thanked 48 Times in 34 Posts
your heater core is partially blocked
flushing out the heater core wont do anything
if your sitting at idle and it blows cold air put in in park and rev the engine
if it gets hotter its partially clogged

i just did one on a 05 accord v6 for the same reason
when i took out the old heater core a sand type substance came out (possible radiator stop leak or mixed matched coolant )

have fun
acrdr is offline
Reply With Quote
Old 02-19-2014, 01:42 PM
#15
Registered Member

Join Date: Mar 2006
Location: Bakersfield
Posts: 20,172
Thanked 1,773 Times in 1,255 Posts
Originally Posted by acrdr View Post
your heater core is partially blocked
flushing out the heater core wont do anything
if your sitting at idle and it blows cold air put in in park and rev the engine
if it gets hotter its partially clogged

i just did one on a 05 accord v6 for the same reason
when i took out the old heater core a sand type substance came out (possible radiator stop leak or mixed matched coolant )

have fun
I bought my TL new and changed the coolant out during the second summer (about a year old I think but it's been a long time since then). I got quite a bit of sand out of the radiator surprisingly. It looked like regular beach sand. I'm sure it was left over from the head and block casting process but I sure am glad I didn't drive it to the full 105,000 miles with all of that sand circulating. Like I said, I bought it new, it had 8 miles on it, no one had ever worked on it so I doubt mine was the only one with sand in it.

The mis matched coolant theory is a good one, I didn't think about that. I've seen coolants gel up from exposure to air (DexCool) and from mixing in compatible coolants.

I guess that would be a good question for the OP, have you ever used a non factory coolant?
I hate cars is offline
Reply With Quote
Old 02-19-2014, 01:46 PM
#16
Moderator

Majofo's Avatar

Join Date: Sep 2008
Location: Waffles, BU
Posts: 77,545
Thanked 9,290 Times in 6,831 Posts
Originally Posted by I hate cars View Post
I still can't believe it's not low coolant.

Anyone know if the heater control valve uses an electric motor/solenoid or vacuum (I know it's cable actuated)?
electric motor
Majofo is offline
Reply With Quote
Old 02-19-2014, 01:51 PM
#17
Moderator

Majofo's Avatar

Join Date: Sep 2008
Location: Waffles, BU
Posts: 77,545
Thanked 9,290 Times in 6,831 Posts
Yeah, probably silicate additives found in the coolant. If left in too long, it starts to harden and clog the lowest points of the flow.
Majofo is offline
Reply With Quote
Old 02-19-2014, 06:45 PM
#18
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
Doesn't Acura recommend changing coolant very 2 years. I have done mine 3 times in the 8 years I have had the car (roughly every 33K or so)
YeuEmMaiMai is offline
Reply With Quote
Old 02-19-2014, 08:30 PM
#19
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
Got car back tonight-
They pressure checked while cold and hot again, no leaks, no drips. running normal temp.
They noticed by the radiator the foam was soaked with radiator fluid may be causing steam and odor. Could be from filling and re-checking rad fluid. They watered it down, not sure about that?
Inside the car-145 degrees while driving, 90 degrees at idle(since the weather is a little warmer outside 28degrees) the cabin seems ok.
I don't think the problem is resolved since there is a difference in temp in the car.
I suggested to them about the TB too. but "either the water pumps works or don't" is that right?
The reservoir is at max when I came home.
Not satisfied.
Might have to hit different dealership?
I'm lost.......... and getting beat.....
bandits31 is offline
Reply With Quote
Old 02-19-2014, 09:08 PM
#20
Registered Member

Join Date: Mar 2006
Location: Bakersfield
Posts: 20,172
Thanked 1,773 Times in 1,255 Posts
Typical dealership know nothings. Looks like you're going to have to do it yourself.

If you don't have one, buy an IR thermometer. One if the $20 ones will be fine for this. Shoot the temps of everything, both radiator hoses, both heater hoses, the thermostat housing, the radiator if you can. Do it after idling and with the rpms above idle. Post your your results.

Did they do the thermostat when they did the timing belt?

Is it engine rpm or load that causes the heater to work?

When the heater goes from warm to hot, do it do so nearly instantly or does it take a minute?

Does the car warm up as quickly as it always has from a cold start?

The water pump is powered by the smooth backside of the timing belt, not the cogged side. It most definitely could slip bit it's very unlikely.

Does the water control valve open all the way? Try it by hand if you have to.

It would be really good to have coolant temp data when you're performing some of these tests. Do you have any sort of a scanner? The dealer should be able to figure it out easily by looking at the coolant temp under various conditions. This is very easy stuff. If the coolant is up to temp it's not the thermostat. If the radiator gets warm it's not the water pump.

I've had my TL in 17F weather and obviously it took longer to warm up but once warm the heater did not have enough output to lower coolant temp even sitting at idle. Plus the coolant is used to cool the EGR so you have a heat source from the exhaust as well.

Once you know it's not the pump and it's not the thermostat and you know the coolant is up to full temp and stays there it starts pointing to a flow restriction between the engine and the heater core like the valve mentioned or the heater core itself as someone said.

Has it always had the factory blue coolant in it?
I hate cars is offline
Reply With Quote
Old 02-20-2014, 12:18 AM
#21
Moderator

Majofo's Avatar

Join Date: Sep 2008
Location: Waffles, BU
Posts: 77,545
Thanked 9,290 Times in 6,831 Posts
Yeah, definitely sounds like the stealership half-assed the diagnosis. IHC is spot on. I would start at the heater control valve and hit the IR therm at both sides of the heater core inlet / outlet.
Majofo is offline
Reply With Quote
Old 02-20-2014, 06:20 PM
#22
Banned

Join Date: Aug 2003
Location: North, NJ
Age: 39
Posts: 186
Thanked 48 Times in 34 Posts
Your heater core is partially clogged
it has to be replaced
heater valve is like on-off switch cable controlled
on the fire wall below your strut brace
try putting a mark on the little arm mark the arm and the little screw in center
turn the temp to high and check if the marks moved
if the arm mark moved but the scew didnt then you have a bad heater valve
if its hot inside the car when driving it means its open and it will stay open at idle as well
acrdr is offline
Reply With Quote
Old 02-24-2014, 06:31 AM
#23
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
"stealership" Thats funny!!! I can laugh about that one.

Anyways,
The heater core flush with new thermostat and pressure test -local garage
Radiator fluid is light green.
Timing belt done-with wp, pretty sure he didn't change out rad.cap.
I will try all suggestions this weekend. Hopefully I can manage through this. I'll print out page
Will keep everyone updated on status
thanks
bandits31 is offline
Reply With Quote
Old 03-01-2014, 06:14 PM
#24
Registered Member
Thread Starter

bandits31's Avatar

Join Date: Feb 2011
Location: Bellefontaine,Ohio
Posts: 14
Thanked 0 Times in 0 Posts
I'll see if I can write this correctly,
Coolant is below min.mark on reservoir when car is cold.
I let car run for 15-30 mins and it's above max mark.
There are no leaks but I can smell anti-freeze
The fan did not kick on at all. Until I turned on AC.
With AC off
I turned on fan to high
It still blows out a little warm air, I turned down temp for cold air, it was cool. but not cold.
Went for drive and blew out hot air until I stopped, blows out warm air.
(Outside temp today is 40 degree)
I looked at heater control module, it looks like it's working? but when I turned on cold temp it was stuck for a sec until I try to make a mark with a pen and it retracted up, hmmmm? I turned temp up and cable pushed it down. How far is suppose to go up and down?
Hose from top of radiator to thermostat was hot but hose from thermostat to bottom of radiator took about 15 mins to get hot.
I'll go buy a IR thermometer tomorrow, and give u actual temp
Kind of hot on hands lol
any opinions? I wish I knew how to install a pic?
bandits31 is offline
Reply With Quote
Old 03-03-2014, 08:46 PM
#25
New Member

Join Date: Jan 2014
Age: 40
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Had the same exact symptoms. I was also stumped. Then the other day when I started the car I heard a small pop. Then I saw white smoke coming from the exhaust. When I got out to look I saw it was actually more like steam. Never overheated. Surprisingly and fortunately no water in oil. I think your head gasket has a small leak and will probably go out soon.
dreyes78 is offline
Reply With Quote
Old 03-17-2015, 10:28 PM
#26
New Member

Join Date: Mar 2015
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
The coolant levels on your reservoir are for cold readings. It is ok to fill to max when cold. To be on the safe side of not overfilling, keep it in between the min and max. Once the car heats up, it will always read above the max line as long as you have the minimal amount in the reservoir. I have the same issue with an 04 TL I'm selling now. My mechanic has fixed this same issue on 3 different cars I've sold before. I'll ask him what he does to fix them when he looks at this one tomorrow. Whatever he does, the problem is always fixed, and it doesn't take long and only charges me $20.
quanmega is offline
Reply With Quote
Old 03-21-2015, 08:08 PM
#27
Scotch

scottn3's Avatar

Join Date: Oct 2010
Age: 39
Posts: 97
Thanked 20 Times in 6 Posts
I'd be curious to hear what you mechanic says. I have this exact same problem and have changed the obvious parts to try to fix it. No luck yet...
scottn3 is offline
Reply With Quote
Old 03-21-2015, 10:25 PM
#28
Fearless DIY Guy
iTrader: (2)

DeathMetal's Avatar

Join Date: Jan 2008
Location: Jersey 'Burbs
Age: 37
Posts: 2,994
Thanked 361 Times in 200 Posts
Two likely culprits, both easy to fix via DIY:

(1) The heater control valve, which controls coolant flow for purposes of air circulation; replace this first.

The linkage arm controls to an opposite articulating gear in the cabin which controls the damper gate for cool/warm air.

(2) Recalibrate the damper position. This is easily done by disconnecting the linkage, verify the post is in the proper position w/ the car on FULL HEAT, then reconnecting the linkage. That re-establishes the highest point for hot air exhaust.

I'd start there. IHC has an awesome insight far superior to well...all, but I'd start with the obvious first. There are DIYs on this not featured in the garage and can be found via search.

Last edited by DeathMetal; 03-21-2015 at 10:28 PM. Reason: Didn't see IHCs post.
DeathMetal is offline
Reply With Quote
Old 11-19-2015, 05:12 PM
#29
New Member

Join Date: Nov 2015
Age: 39
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
2006 Acura Heater not working at idle

My car does not warm up in the morning. Once it starts, it blows cold when I am idling. Did you ever resolve your issue?
OakleyM is offline
Reply With Quote
Old 11-19-2015, 08:48 PM
#30
Registered Member

deepa1600's Avatar

Join Date: Nov 2015
Location: ontario
Posts: 100
Thanked 13 Times in 11 Posts
Originally Posted by bandits31 View Post
2007 TL w/104k
I live in Ohio so its cold!
Driving down the road, nice and warm in the car, when I come to stop, it blows cold air.
What I've had done so far.
Timing belt-done at 100k 2013
Tune up at 104k 2013 dealership
Winter of 2013 the issues begin!
11/13 New thermostat, -my acura/Honda mechanic
Same Issue Still
12/13 New thermostat, pressure check, burb. -Dealership
They suggested possible radiator cap and flush heater core. (dealership does not perform heat core flush)
Same Issue Still
1/14 Heater core flush with new thermostat and pressure test -local garage
Same Issue Still
Sometimes when I turn off car it smells like antifreeze and looks like steam coming off the front but no leaks on ground
I don't know what else to do????
(wife isn't too happy either)
lost....help!
About cold air when stopping at light or stop sign. Probably air pockets in cooling system if coolant was drained. Probably have to let the air bubbles out and add more coolant.
deepa1600 is offline
Reply With Quote
Old 11-22-2015, 11:34 PM
#31
Registered Member

eastcoastguy's Avatar

Join Date: Nov 2012
Location: Springfield, MO
Age: 39
Posts: 662
Thanked 104 Times in 91 Posts
Ever since I bought my car (used), the heater never really blew that hot but I figured maybe that was the norm for this car. But it got cold the other day and I used the heater and noticed it was warmer during driving and not as warm at idle. Will try whats suggested in this post but it seems things were left unfinished. Any answers?? This seems like it could be a common issue?
eastcoastguy is offline
Reply With Quote
Old 11-23-2015, 01:01 PM
#32
Registered Member

deepa1600's Avatar

Join Date: Nov 2015
Location: ontario
Posts: 100
Thanked 13 Times in 11 Posts
Originally Posted by eastcoastguy View Post
Ever since I bought my car (used), the heater never really blew that hot but I figured maybe that was the norm for this car. But it got cold the other day and I used the heater and noticed it was warmer during driving and not as warm at idle. Will try whats suggested in this post but it seems things were left unfinished. Any answers?? This seems like it could be a common issue?
Anytime a car has cold air at stop and warm at driving, it's most likely air pockets in cooling system. watch this video
deepa1600 is offline
Reply With Quote
Old 11-25-2015, 10:06 AM
#33
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
the system will self bleed over time.... Honda used to put nibbles on their thermostat housings to aide in the bleeding process
YeuEmMaiMai is offline
Reply With Quote
Old 12-01-2015, 10:57 AM
#34
Registered Member

Join Date: Jun 2012
Posts: 260
Thanks: 0
Thanked 11 Times in 11 Posts
at one point half of my vents were blowing cold air and the other half warm air. The dual switch was not on, and I noticed sometimes I would get warm air on idle and hot air when driving. I decreased the temp all the way, and then increased it, and then decreased it and then it magically worked. Also my vents smell a little moldy, so I just drive with the heater on feet and that works for me. Not sure if anyone knows an easy fix for the smell.
zubi23 is offline
Reply With Quote
Old 12-02-2015, 06:30 AM
#35
Registered Member

Join Date: Sep 2006
Posts: 9,843
Thanked 430 Times in 338 Posts
^ check your actuators.... if one side has heat and the other does not, it's not a heater core issue.
YeuEmMaiMai is offline
Reply With Quote
Old 03-28-2016, 11:27 PM
#36
New Member

Join Date: Mar 2016
Age: 42
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
No heat at idle, but heat when accelerate or rev engine

I have a 2008 TL, had the same low or no heat at idle, but did have heat when I revved the engine or accelerate. Checked the heater control valve which opened visibly when the heater control was on cold and then I increased the setting to hot. I even removed the 2 heater hoses and forced water through the heater core to see if it was clogged. Not clogged, same issue. Solution: I had air in the system, even though I had tried to remove it several times. The way that worked was the revving of the engine with the radiator cap removed until all bubbles were gone. Took longer than I thought at 1500 rpm, and it was 32 degrees outside when I did this, so the cooling fan never came on. Just rev it up and keep an eye on the top of the radiator to watch the air bubbles. See the link or just the steps below.

https://techinfo.honda.com/rjanisis/...101O00241A.pdf

First steps are for draining radiator, use proper 50/50 antifreeze, etc.
8. Start the engine and let it run for about 30 seconds. Then turn off the engine.
9. Fill the radiator with coolant up to the base of the filler neck.
10. Fill the reserve tank to the MAX mark. Install the reserve tank cap.
11.Install the radiator cap, and tighten it to the first stop.
12.Start the engine and let it run until the radiator cooling fan comes on at least twice. Then stop the engine.
13.Remove the radiator cap. Pour coolant into the radiator up to the base of the filler neck and into the reserve tank up to the MAX mark.
14.Start the engine and hold it at 1,500 rpm until the cooling fan comes on. Turn off the engine. Check the coolant level in the radiator and add coolant if needed.
15.Install the radiator cap, and tighten it fully.
16.If necessary, fill the reserve tank to the MAX mark. Install the reserve tank cap.
Attached Files
File Type: pdf
Radiator fill instructions.pdf (133.8 KB, 170 views)
Joe O is offline
Reply With Quote
Old 11-21-2016, 03:16 PM
#37
Registered Member

Join Date: Jan 2016
Age: 25
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
same problem, 2006 TL

Originally Posted by Joe O View Post
I have a 2008 TL, had the same low or no heat at idle, but did have heat when I revved the engine or accelerate. Checked the heater control valve which opened visibly when the heater control was on cold and then I increased the setting to hot. I even removed the 2 heater hoses and forced water through the heater core to see if it was clogged. Not clogged, same issue. Solution: I had air in the system, even though I had tried to remove it several times. The way that worked was the revving of the engine with the radiator cap removed until all bubbles were gone. Took longer than I thought at 1500 rpm, and it was 32 degrees outside when I did this, so the cooling fan never came on. Just rev it up and keep an eye on the top of the radiator to watch the air bubbles. See the link or just the steps below.

https://techinfo.honda.com/rjanisis/...101O00241A.pdf

First steps are for draining radiator, use proper 50/50 antifreeze, etc.
8. Start the engine and let it run for about 30 seconds. Then turn off the engine.
9. Fill the radiator with coolant up to the base of the filler neck.
10. Fill the reserve tank to the MAX mark. Install the reserve tank cap.
11.Install the radiator cap, and tighten it to the first stop.
12.Start the engine and let it run until the radiator cooling fan comes on at least twice. Then stop the engine.
13.Remove the radiator cap. Pour coolant into the radiator up to the base of the filler neck and into the reserve tank up to the MAX mark.
14.Start the engine and hold it at 1,500 rpm until the cooling fan comes on. Turn off the engine. Check the coolant level in the radiator and add coolant if needed.
15.Install the radiator cap, and tighten it fully.
16.If necessary, fill the reserve tank to the MAX mark. Install the reserve tank cap.
I am experiencing this exact issue. i bled the coolant system of air to the best of my ability this past weekend, followed the step the ErictheCarGuy video and your instructions, topped it off when hot etc etc. Waited for the fan to come on twice and everything. Still no heat. How exactly were you able to get to the heater hoses? what hoses are they and where are they located? the heater control valve is not exactly easy access
riversnj is offline
Reply With Quote
Old 11-22-2016, 06:30 PM
#38
New Member

Join Date: Mar 2016
Age: 42
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
The heater control valve is behind the engine by the firewall. See pictures. There is a cable attached to it. Have someone sit in the car, turn the temperature to cold. Then you can watch this valve while the person turns the temperature to hot as it will go. You should see this valve open - the cable moves the valve. The 2 heater hoses are right there by the the heater control valve. Disconnecting those hoses was a major struggle, and I'm guessing your hoses are fine and the heater core (it's just a small radiator) is fine. Also, one thing I did was to park the car on an incline where the front of the car is higher than the back. I figured this would help the air bubbles come to the top where the radiator cap is, but I assume that's not really needed. With the radiator cap off that whole time while doing this exercise of draining coolant, filling it again, etc, I sat in the car and kept the rpm at 1500 rpm with the hood up at that step. I was able to look under the hood and see the radiator cap area and watch the air bubbles come out. I just kept the rpm at this level until I didn't see any more bubbles. It took a little bit of time... maybe 10 minutes? I can't remember, but I was surprised that bubbles kept coming for that long. Hope this helps.
Attached Thumbnails Heater blows warm while driving-Blows cold air at idle!-cam01780.jpg Heater blows warm while driving-Blows cold air at idle!-cam01779.jpg
Joe O is offline
Reply With Quote
Old 11-22-2016, 06:42 PM
#39
Moderator

Majofo's Avatar

Join Date: Sep 2008
Location: Waffles, BU
Posts: 77,545
Thanked 9,290 Times in 6,831 Posts
Majofo is offline
Reply With Quote
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rp_guy
Member Cars for Sale
9
07-16-2017 07:33 AM
rcs86
Car Parts for Sale
3
08-02-2016 06:52 PM
detailersdomain
Wash & Wax
3
10-09-2015 10:13 PM
jmaxima03
Member Cars for Sale
1
09-27-2015 10:22 AM



Quick Reply: Heater blows warm while driving-Blows cold air at idle!


Contact Us Terms of Service



We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.