2000 Honda Civic overheating after replacing thermostat and coolant in radiator?

Answer 1

My girlfriend's friend just left her 2000 Honda Civic in my garage because it was overheating and they were gonna go to the club. Of course I am supposed to fix it or I look bad. Anyway, after checking the coolant reservior to find it bone dry I fill it with pre-mixed coolant and run it through the system as I take it for a drive around the block. It quickly shoots to red when I hit 40MPH and I pulled over to check it out. Bubbling from the top of the radiator. If the thermostat and coolant on your vehicle has been replaced try turning it on for a few minutes and checking for any leaks or bubbling emanating from anywhere in and around the radiator. A radiator for that model vehicle usually runs around $95.00 and is fairly easy to get a hold of. Another factor could be the time of year. If it's a hot summer and you've got the A/C running, check to make sure the fan is working. Usually the fan won't come on unless the A/C is on, so try it out. Hope this helps.

Edit by SmokeShank:

Make sure the coolant system was properly bled after the work was performed. The proper way to bled the civic cooling system is to leave the radiator cap off. Turn the inside heater on, you dont need the fan on, but the heater/ac switch needs to be set to hot. This allows coolant to enter the heater core inside the vehicle to expell any trapped air. Let engine warm up fully (This means that the radiator fan kicks on once, or twice). Top off fluid as you go. Also note as the car warms up (and you have the radiator cap off) the coolant expands as it heats and will over flow the radiator. Dont panic, this is normal. Just place some sort of catch pan underneath the car to keep coolant from going all over the floor. Once the radiator fan has kicked on, turn off the car and top off fluid. Place the radiator cap back on. Top off the fluid in the resovior if you have not done so yet (This is important). When the car cools, it will pull fluid from the resovior back into the radiator/cooling system. There is a tool that costs around 15-25.00 that will make this process easy and mess free. Its a funnel that plugs directly onto the radiator so you wont have a mess on your floor. I picked one up from Matco. Here what it looks like ( http://www.pten.com/images/article/1226593973729__Matco_SpillFreeFunnelwi_PTEN_0.jpg )

If you do this, or already performed the proper bleeding and it still over heats, you may either have a bad water pump or its possible that the head gasket has blown from an over heat condition. If the head gasket did blow, it is VERY possible that the civic head has warped. The civics aluminum heads can warp very easily. About 75% of the head gaskets I do on civics, the heads do not come out "True" (exactly flat, meaning they warped). If it is warped, you will need to send the head to a machine shop and have it milled flat.