We're adding and testing new features:  Create your Garage, used it? Give us some feedback here.
Honda Civic Forum Home - Honda Civic Classifieds - Civic Photo Galleries - Create an Account

Go Back   HondaCivicForum.com > General Automotive > Mechanical Problems & Technical Chat
Sign in using an external account
Register Forgot Password?
Search



Welcome to the HondaCivicForum.com.
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Display Modes
  #1  
Old 02-24-2010, 07:28 AM
Junior Member
 
Join Date: Feb 2010
Posts: 2
Default Please Help! My Heat only working while driving and now its overheating!

The heat in my 2004 civic ex vtec only works when Im driving.. when I stop or go slow.. Im freezing.. thats been going on for a while.. more recently, now it overheats ..sometimes it cools down as I begin to drive again, or if Im on the highway and the heat actually works, that will cool it down too..

I have changed the thermostat, coolant is good and I switched all the relays and each one is good.. Yesterday I left it idle in the driveway and when it was completely overheating, the fan never kicked on under the hood. Although, when I turn the AC on, Both fans work properly..

What else do I do!!! Any suggestions?? Thanks
Reply With Quote
  #2  
Old 02-24-2010, 07:40 AM
Recognized HCF Member
 
Join Date: Jun 2007
Posts: 9,812
Default

Does the radiator actually stay full of coolant? Don't just check the plastic tank.

Heater only works while driving is a classic symptom of low coolant level, which would then lead to overheating as it gets worse.

You may have head gasket damage from overheating, that will blow the coolant out of the radiator. To check that, take the radiator cap off (of course, never uncap unless engine is COLD), start the engine and rev it, see if any bubbles occur in radiator.

Last edited by mk378; 02-24-2010 at 07:47 AM.
Reply With Quote
  #3  
Old 02-24-2010, 07:50 AM
HCF Member
 
Join Date: Oct 2008
Location: minnisnowta
Posts: 69
Default

your blower motor is messed dude.
hence the heat only moving when your car is moving.
unless i guess you can feel it blowing through the vents
__________________
herbs and hondas make my day
Reply With Quote
  #4  
Old 02-24-2010, 08:19 AM
WellFedHobo's Avatar
Moderator
2000 Honda Civic
 
Join Date: Jul 2007
Location: Arkansucks
Posts: 4,943
A Well Fed Hobo
Default

^Doubtful that the blower motor is bad. Much more likely a coolant issue.
__________________


Quote:
Originally Posted by RonJ
Don't guess, Troubleshoot.
Reply With Quote
  #5  
Old 02-24-2010, 08:50 AM
RonJ's Avatar
Recognized HCF Member
1997 Honda Civic
 
Join Date: Sep 2007
Location: Houston, Texas
Posts: 9,450
Default

Top off the coolant in the radiator and reservoir and then bleed the cooling system.

Bleeding:

Set the heater to max heat and then do this,

Click the image to open in full size.

Last edited by RonJ; 02-24-2010 at 08:54 AM.
Reply With Quote
  #6  
Old 02-24-2010, 11:29 AM
HCF Member
 
Join Date: Oct 2008
Location: minnisnowta
Posts: 69
Default

welllllll
why is his heat only working when he"s driving fast?
__________________
herbs and hondas make my day
Reply With Quote
  #7  
Old 02-24-2010, 11:37 AM
WellFedHobo's Avatar
Moderator
2000 Honda Civic
 
Join Date: Jul 2007
Location: Arkansucks
Posts: 4,943
A Well Fed Hobo
Default

Working theory is that he's low on coolant. When the car isn't moving and the engine is idle, the air blows cold. When the car is moving and the RPMs are higher, there is enough pressure built up to move the hot coolant through the heater core, where before there was only air. When at idle, there isn't enough pressure to move the coolant through the block. Hence, overheating.

If this is the case, the next question is what caused him to be low on coolant. Is there a leaky hose? a damaged head gasket? a cracked radiator? Don't know. Hence, troubleshooting.
__________________


Quote:
Originally Posted by RonJ
Don't guess, Troubleshoot.
Reply With Quote
  #8  
Old 02-25-2010, 10:57 AM
HCF Member
 
Join Date: Oct 2008
Location: minnisnowta
Posts: 69
Default

thank you for the clarifacation.
that would make beyond comon sence.
__________________
herbs and hondas make my day
Reply With Quote
  #9  
Old 02-25-2010, 11:42 AM
StifflersMom's Avatar
Cat Fuсker
 
Join Date: Nov 1978
Location: The Moon
Posts: 6,780
Default

When you think of the cooling system as a whole and know what happens when the engine speed changes than it is common sense. Air in the heater core can also occur if you have someone flush the cooling system and not bleed it properly.
Reply With Quote
Old 02-25-2010, 11:42 AM
 
 
 
Reply

Tags
2004, blow, blows, civic, cold, driving, fan, fast, heat, heater, idle, idoling, im, overheating, works

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
Civic Custom Rims
AMSOIL - Performance Oil Technology
K&N Engineering
Advertise Here
All times are GMT -8. The time now is 12:21 PM.

Internet Brands, Inc.
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.


Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for HondaCivicforum.com content, comments, or advertising. HondaCivicforum.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse HondaCivicforum.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.