I have a 99 civic that with 139k on it that keeps running hot. The car keeps spilling coolant into the reservoir but it does not suck it back into the radiator when the car cools down and I have to keep pouring the extra coolant from the reservoir back into the radiator each time i drive the car to keep it from over heating. After a drive of about 50 miles I notice it starts to run hot again and then if i look at the reservoir its filled all the way to the top. I had three radiator caps put on but none helped, it has a new radiator, new sensors related to the cooling system, new thermostat - changed 2 times to test it and the car has had 3 head gasket tests done by 3 different mechanics all said it passed. I had the coolant flushed and replaced also and still problem remains. what else could cause this? I am at my wits end already with this All three drive belts have been replaced also.
If you watch my video, how to fix an overheating car engine, Scotty. It has to be one of those things. Mechanics you're dealing with seem to be idiots. Often it can just be worn out radiator. That's clogged up inside and it won't cool the engine off. Any mechanic knows how to test that stuff. They seem to be a bunch of idiots. If you're anywhere near Clarksville, Tennessee, I'll check it out for free
Well the radiator is only 2 years old do you think it could be a water pump issue?