Hey everyone, I recently got help for my previous heating problem (thanks again for those who contributed), but now have a new heating concern.

After resolving my busted heater hose, I thought everything is finally cool. But today, I drove for a good 15-20 minutes by freeway when all of a sudden my temp gauge shot up 3/4's of the way up. When I turned on my heater, some relief came and my temp gauge went down to about 1/4. This happened twice. Now, after a few minutes of rest, I decided to try my luck again and go for some starbucks. So far as I arrived, it went up to 1/3 when idle, with the fan running.

What is this a symptom of? Bad thermostat? Bad thermostat switch? Bad water pump?

Note: My radiator fan is acting weird. I turn off the engine, but the fan keeps running. Once I open my car door it stops. Wtf?

 

The fan continuously running is the sign of fan relay being stuck in the on position.

Run the car shortly and feel both the upper and lower hoses, both should feel warm.

It sounds like your water pump is dying, but im not sure if you bled the cooling system enough when you fixed your heater hoses

 

The sounds like the fans are set to run till the motor is at a certain temperature (do you have an aftermarket timer?)
My next guess would be to make sure you have all the air out of the system, run the car with the heater on as you fill it so that you get all the bubbles are in the heater core. Post results.

 

If the lower hose is still cold your thermostat is sticking closed. If that is the case ALWAYS buy Honda OEM thermostats. They are designed to fail open which is critical.

 

Update: I purged the cooling line of as much air as I could (including opening up the coolant bypass line) and topping off my coolant as Dioxine suggested. So far so good no overheating. It goes as high as 1/3 of the gauge. As far as my fan issues go, I dont think its the relay because if it was, it wouldnt be working at all. I havent gotten to the point of having to change my water pump, cooling fan switch, or my thermostat (just yet). Im hoping to hold off on that as much as I can while gathering the funds...

Once again, thanks for the suggestions, and you all rock!

P. S. To Dioxine: I have no turbo, so I dont have a timer.

 

Well glad you got it all figured out. Keep an eye on the level as some bubbles may work there way back to the top.

 

Update: I have been running my accord in the early mornings going to work at 40- or 50-ish degrees fahrenheit with my heater on full blast. I haven't experienced any problems. But today was my day off, the weather was warm (so I didn't trun on my heater), and decided to take a drive on the freeway to drop off my wifey to work. As I pulled up, my temp gauge shot up past to three quarters, even on idle. When I turned off my engine, I heard a "bubbling" boiling sound, so I checked out my engine. No smoke or anything, but I saw what looks like my coolant overflow tank spilled out some coolant and even bubbles! I pulled out the hose that goes into the tank and saw slight steam from the hose.

What does this mean? Is this a water pump failure or a thermostat failure?

 

Try replacing your radiator cap. When it gets weak it allows coolant to pass through to the overflow tank.

 

Update: So I had a few bucks and some spare time today. I decided to check out my heating problem with one of the most common problems among Hondas: the thermostat. Sure enough, when I opened that housing, to my surprise, there WAS a thermostat. I say WAS becuase there was nothing left of the dang thermostat except for the gasket and neck. NO SPRING, NO COPPER FITTINGS, etc. I wish there was a way I could post the pic but if you had seen it, you would've been like WTF?

Anyways, my temp gauge stays at a constant 1/3 even after a 20-minute freeway drive in this warm San Diego weather, using a fail safe thermostat.

Thanks again to everyone's contribution to this post!

 

GREAT THREAD hope people that need help refrence to this thread and how to go about fixing the issue. Not just "I need help" and never update :/

Just about every one gave the best suggestions I could think of. I would replace the RAD CAP its cheap insurance.

 

I definitely will do this when I get paid next week.