Skip the auto shop - Our mechanics make house calls

Q: Top water hose gets hot with new thermostat

asked by on

Top water hose gets hot with new thermostat and only one side of the radiator is hot
My car has an automatic transmission.

A: Hello. This is completely normal operation ...

Hello. This is completely normal operation of the vehicle’s cooling system. The top radiator hose should always be warmer than the bottom. As coolant flows through the water pockets in the engine it picks up heat, and it is then transferred back into the radiator through the top hose. The coolant is cooled off in the radiator and then is recycled back into the engine through the lower radiator hose. Hence, hot on top, cold on bottom. If your symptoms were opposite, you would have more serious issues. The thermostat’s job is to hold the coolant in place until the engine is warm enough to need allow the flow of coolant through the system. Once the engine is warm enough to warrant coolant flow, the thermostat opens to a degree corresponding to the engine temperature.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Low rough idle and engine stall outs.

Hi there. Though this can be caused by a few different things most of the time it is caused by a failing throttle body. The throttle body will have a failure in the actuator motor and this occurs, most of...

Q: Flashing check engine light.

If you keep having code P0301 come back, and you have replaced the injector, plug, and wire, then you may have excessive carbon build up on the valves or you have low compression in the cylinder. Since you had the...

Q: I have a 2003 Dodge Durango with a 5.9L. It is trying to run hot. I have replaced the thermostat because it looked like it was leaking there.

Hi there. The coolant would be leaking from the heater hoses. Check the clamps to the heater hose clamps and make sure that they are all tight. If the clamps are tight and the hoses are still leaking, then I...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...