2003 Civic Overheating

[copper_top]

Hello,

I have a 2003 Civic Ex Coupe with an automatic transmission. A couple months ago the heater core went out, leaking antifreeze into the passenger foot area, but being a student affording a mechanic wasn't an option, so for the time being I cut the hoses going to and from the heater core and coupled them together (I'm not sure if this has any impact on the current issue or not). After doing so I filled up both the radiator and the reservoir.

Current issue
Recently I've noticed that the engine temperature gets pretty warm in slow or stop and go traffic, the longer I'm stopped the higher it got, never getting into the red. However today on my way to work, in terrible stop and go, it made it past the red and began smoking, I pulled over, the smoke (it was probably steam) was coming directly from the radiator cap, there was splashed antifreeze around the cap as if it was boiling out of the cap. However when I went to add water to the reservoir, it was totally full, exactly how it was a few months ago. I waited until the engine was cooler and continued to drive to work, however the engine didn't get cooler as I reached higher speeds like it used to it would just heat up and stay hot. So I pulled over, turned on the car without turning on the engine, cooled it to half way, drove more, and repeated this until I got to work.

Ideas as to what the problem is
Based off of what I've searched it seems some of the possible issues include air in the radiator, bad radiator and/or thermostat, blown head gasket, radiator is out of coolant, or a bad fan, (however I did see that both radiator fans did run while I turned the car on but left the engine off).

Any ideas as to
a) What the problem is
b) How to fix the problem
c) How to get the car home in one piece to fix it without getting a tow

Thanks so much for the help, sorry for the long post

 

[ss202sl]

Thermostat?

 

[wip99gt]

It controls the coolant flow from the engine to the radiator. Engines run best at a certain temp so you want to maintain it. Too cool or too hot isn't good.
You most likely have air in the sytem which was previously stated. You can try parking the car at an incline with the rad higher than the engine and try filling there.
Hardwarefreak has some good ideas there. A pressure tester is golden in this scenario. First you can increase the cooling system to max psi which should be stated on the rad or rad cap. Then watch to see how quickly the pressure drops or if you see an external leak. Watch the head gasket area, waterpump, and coolant hoses as those will be the most likely areas. If you don't see anything then release the pressure. With the pressure tester installed but not pressured up start the car. Watch to see if pressure rises quickly. If so then it's a sign of a head gasket leak because that's most likely gases from the cylinders leaking past the gasket.
Again, with the fact that it was running well until you drained the coolant to remove the heater leads me to have strong suspicions of an air locked system. I have seen this many, many times.

 

[md1032]

OK so first off, you have an overflow tank. If your coolant system has any significant amount of air in it (chances are, it does, because I am guessing you did not bleed the system correctly), then your cooling system will not refill itself from the overflow tank automatically like it should.

Buy a new radiator cap and some coolant (make sure it is the correct coolant - no silicates, and no organic acids, you can buy an off-brand called "Zerex Asian Vehicle" at NAPA or buy it from Honda directly). When the vehicle is completely cold, remove the radiator cap, fill the radiator with coolant, and put the new radiator cap on. Take the vehicle for a drive to warm it up, then park the car, allow it to cool completely, and repeat. If your vehicle is still overheating, you need to replace the thermostat. That is a pretty easy job, just make sure you use a Honda OEM thermostat.

I'm guessing your hack job on the heater core is leaking coolant or pressure somehow. Have you considered just running one of the heater core hoses from the outlet into the inlet (with hose clamps of course) and just storing the other heater core hose somewhere else?

 

[zinsavage123]

The only problem with overheating issues is it can be so many things. Blown head gasket, coolant leak, hose cracked, t-stat faulty, fan switch fried. May want to take some free time if you have any and peek around pretty good. Let car run and peek under car as well and look for obvious if any leaks.

 

[sindako]

First of all , Replace the T-Stat , It's not expensive , also I bet it's already dead ,
Also , IF the Car Ran a lot of steam instead of boiled Water , There are the possibilities :
1: water Leaks , Look for them and Check it when the car get to optimal temp ,
2: Air inside with the cooling system , But still while refilling , Bleed out the air and try driving it in the neighborhood ,
3: Failed Headgasket , Which makes a lot of Compression Loss and Bleeds out the water fast because of the Heat , that can make a lot of steam coming out instead of boiled water .

Also if your car has a Pressure Coolant Cap , replace the cap and test the water pressure , I think it should be 0.9 Bar on your civic . most Japanese car have a water pressure in between 0.6 - 1.0 Bar , For a Stock engine .

 

[wss_003]

Start by making sure your cooling fans are working then look for leaks but from what u said if the rads still full its not leaking so if the fans work and the rads full replace the thermostat and when your done start your vehicle with the cap off the rad until the water starts to circulate then put the cap on and go for a drive