Why Does 1985 CRX Now Run Hot with new Water Pump?

[ascendedmind]

It appears it was an air lock in cooling system.

The mechanic apparently did not open or turn the bleed valve far enough to bleed the air out! After he turned the bleed valve open far enough with a 12mm wrench it started dripping coolant.

Then he slowly added coolant into radiator until it was finally burped of air.

After that was solved I checked the heater but still no heat!

So the mechanic checked the Heater control Panel by switching the heater control lever back & forth. The Heater Control cable became loose & detached itself, so he tweaked the cable with needle nose pliers to prevent the cable from detaching itself again.

[Poodwaddle]

Originally Posted by ascendedmind

4. Note: The top radiator hose gets warm, but not the bottom house. What does this indicate?

If the radiator hose that contains the thermostat is cold then it means the thermostat isn't opening. If it is hot and the return is cold then it means that there is no flow through the radiator. The fact that it started when you replaced the pump suggests an air bubble. Try starting the car (from cold) with the radiator cap off and let it run for 20 minutes or so until the thermostat kicks on. Bubbles will start to come up. You can rock the car back and forth to encourage bubbles to break free.

If this car has a sealed reservoir then check the reservoir lines (connected to the radiator cap) for any sign of cracks or leaks. Even a tiny hole will cause the coolant to steam out. This will reduce the pressure inside the radiator. Reduced pressure means lower boiling point, causing gradual temp rises.

[me and my metro]

Mystery solved, I even looked at pictures of the waterpump to see if any other problems were obvious.

[Poodwaddle]

Originally Posted by me and my metro

Mystery solved, I even looked at pictures of the waterpump to see if any other problems were obvious.

Don't keep us in suspense. I really wanna know what the problem was.

[me and my metro]

See post 11

[ascendedmind]

Originally Posted by Poodwaddle

If the radiator hose that contains the thermostat is cold then it means the thermostat isn't opening. If it is hot and the return is cold then it means that there is no flow through the radiator. The fact that it started when you replaced the pump suggests an air bubble. Try starting the car (from cold) with the radiator cap off and let it run for 20 minutes or so until the thermostat kicks on. Bubbles will start to come up. You can rock the car back and forth to encourage bubbles to break free.

If this car has a sealed reservoir then check the reservoir lines (connected to the radiator cap) for any sign of cracks or leaks. Even a tiny hole will cause the coolant to steam out. This will reduce the pressure inside the radiator. Reduced pressure means lower boiling point, causing gradual temp rises.

Poodwaddle, thank you very much for your sharing your knowledge, it has been very helpful.

[ascendedmind]

Originally Posted by Poodwaddle

If the radiator hose that contains the thermostat is cold then it means the thermostat isn't opening. If it is hot and the return is cold then it means that there is no flow through the radiator. The fact that it started when you replaced the pump suggests an air bubble. Try starting the car (from cold) with the radiator cap off and let it run for 20 minutes or so until the thermostat kicks on. Bubbles will start to come up. You can rock the car back and forth to encourage bubbles to break free.

If this car has a sealed reservoir then check the reservoir lines (connected to the radiator cap) for any sign of cracks or leaks. Even a tiny hole will cause the coolant to steam out. This will reduce the pressure inside the radiator. Reduced pressure means lower boiling point, causing gradual temp rises.

Like I said Poodwaddle the mystery was finally solved with simple fix revealed in post this morning.