hrow away the pressure relief cap, tighten the clamps. add coolant when cool, add a little uv dye. start and let idle. use the uv light. check for leaks. pressure raises your boiling point, keeping the coolant in liquid form. if your still leaking/building pressure, get a gas sniffer above the radiator fill

If the water-pump "weep-hole" on the bottom of the *pump input shaft casting is leaking, you need to replace the water pump.If it is not, you need a Honda Dealer to do an inexpensive *cooling system pressure test which will find any external or internal cooling system leaks.

That quick overheat sounds like a cracked head or blown head gasket. With the engine cold, remove the radiator cap then start the engine. If it starts churning out water within two minutes you do have cracked head or blown gasket.

Yes

buffalo ny: i don't know, but cartalk.com is a good place to look. see similar problem at: http://community.cartalk.com/discussion/... it's always a good idea to have a dealer or recommended mechanic look at a problem like this that can ruin an engine. let them diagnose it for you also so any factory recalls or updates can be checked as well.

You have taken care of the easy stuff, now to that water pump.

so i have a '98 civic ex coupe that i just bought with an overheating problem for very cheap. I was told it has a new radiator put on.

I recently put a new thermostat and changed the oil and the coolant resevoir(which leaked) the car runs but after about 5 minutes starts to over heat i don't see any steaming or smoking from under the hood but after i park there is a drip coming from under the radiator off the plastic bumper guards, before there was a smoking/ steaming coming from the timing belt area so im thinking water pump but after seeing this coolant drip im wary of what to do.