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david, Auto Service Technician
Category: Car
Satisfied Customers: 1500
Experience:  Certified Master Technician,Certified in diesel & gasoline engines
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Radiator hose..thumping..heater core and my temperature is..half way

Customer Question

my upper radiator hose is thumping. very little heat coming from heater core and my temperature is up and down almost pegged in the normal and back to about half way
Submitted: 7 years ago.
Category: Car
Expert:  david replied 7 years ago.
Hi thank you for your question hope this helps.

First thing i would do is make sure the coolant is full.

If it is full You need to get the coolant system presser tested.

This sounds like you may have a bad head gasket.

I hope this helps
Good luck
Customer: replied 7 years ago.
it is a rebuilt motor the heads were placed buy the factory it was hot tested and only been in car for one week max new water pump new upper and lower radiator hose radiator was replaced less than a year ago in morning i check coolant it is max both in reservoir and in radiator temp usually rises on decelaration after i arrive at a location the temp is almost at the end of normal range on gauge and i can hold upper radiator for quite a while before it feels really hot
Expert:  david replied 7 years ago.
I am thinking there may be some air trapped in the system.

Did you bleed the cooling system after replacing the water pump, upper and lower radiator hose's?

This would explain the temperature gage jumping up and down along with the radiator hose thumping and the heater not getting hot. Because the temp sensor will not read air.

An easy way to bleed the air from the system is start the engine and open the radiator cap and let the engine run till operating temp. watch the coolant level add more if needed. Till you see no more bubbles.