I have a 1987 Honda Civic si, fuel injected, 1.5 L engine. I recent drove it about 50 miles when it started overheating. I took it home and changed a bunch of the older hoses. I then flushed the coolant. It was still overheating. I then changed the thermostat. It is still overheating. Now the car will warm up normal and then start idling erratically and then start overheating. I check the water pump and changed the V and serpentine belts to be sure. I am Stuck. Any help would be appreciated.

 

you may have an air lock in the cooling system take your cap of squeez the top radiator hose a bunch of time and see if that farts out any bubbles if not there should be a bleeder valve on the top neck where the coolant hose hooks to the block. start the car up let it warm up and build some pressure then crack the bleeder open and if any bubbles pour out of it keep doin it untill they go away.

 

Thanks a bunch it seemed to work.