I have a 1998 Honda Civic EX. 166xxx miles. I just had the water pump and radiator replaced. Even after these repairs my car is still overheating. Initially the temperature will be normal (half way point on gauge) and after approximately ten minutes it creeps up. Sometimes it will go down a little, but eventually it goes back up and I have to shut the car down before it hits the red. Any ideas? The cooling system was pressure tested and there were no leaks.
Thanks.

 

Bleed the cooling system (procedure may take 20-30 minutes):

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below (your engine does not have a bleed bolt so skip that step below):

 

Thanks!! I think it worked. How does this happen? Why do I have to add coolant? Is it possible I have a leak?

 

When the cooling system is drained and refilled with coolant, air generally becomes trapped in the system. Bleeding removes this trapped air, which can block normal coolant flow and cause engine overheating.