Ok so I have a 2000 Civic Ex that is overheating. I took it to a mechanic to see if they could just look at it. They checked for leaks, no leaks. They checked the fan, fan was fine. Radiator was brand new. They checked the coolant, said it was low and did a coolant flush. I took the car home and drove it around. It started slightly overheating while idling but cooled once I started driving again. Now I get about 20 minutes down the road and the check engine light flashes and the motor would seem to not want to go anywhere. I kept my foot on the gas and it would just go back to normal driving after a few moments. The engine light would stop flashing, everything would be normal until I had to come to a stop and pick back up again. So I went and had my spark plugs, wires, rotor, and distributor cap replaced. Car seemed to be running really well, nomore sputtering. Now before all the new plugs were put it, the guy doing it said he could feel the motor "thumping". I guess I should add we did a diagnostic scan and it came back with a cylinder 1 and 2 misfire, also (bank 1 sensor 2) circuit low input. Now with new plugs and wires I went home. Half way there my engine started to overheat. I got back and did a compression test on all 4 cylinders and got a reading of 160ish PSI. The second cylinder did not crank as high, it was in the 150 range, also was a dry test. Now after this I read online another way to test for a blown head is to leave the radiator cap on and start the car, if it shoots up like a geyser its a head problem. Anyways so it shot up, I put the cap back on and now decided to get others inputs. Is the radiator cap thing true? Anyone else have a problem like this?

Car Information-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

2000 Honda Civic EX 5 spd Manual
D16ya motor-rebuilt
Less then 50k miles

 

easy not enough coolant or stuck thermostat

 

Yes if coolant shoots out of the radiator when you rev the engine cold with the cap off, the head gasket is blown. That is rather conclusive. On a good engine there is little or no action in the radiator until after the engine warms up.

Your repeated driving overheated isn't helping things.

 

OK I didn't rev it with the cap off. I took the cap off, started the car, and coolant shut up. I am going to go out and try reving it with the cap off though. Also while the cap was off I didn't see any bubbles coming up from inside the radiator. I'm thinking now it could be a bad water pump? But if it was the water pump wouldn't it overheat all the time and not just in idle?