Skip the auto shop - Our mechanics make house calls

Q: Question about thermostat replacement and radiator cooling fan switch replacement

asked by on

I have two quick questions:

  1. When your mechanic replaces a thermostat and radiator cooling fan switch, does he do air bleeding when the replacement is done?
  2. When doing the replacement, does your mechanic drain all of the coolant in the cooling system, or simply does he add some additional coolant when done?

Thanks for your time and help.

My car has 150000 miles.
My car has an automatic transmission.

Hi there. Anytime the coolant system is worked on, a professional mechanic should verify the service steps with the manufacturer’s service guide. This will help them determine the right steps to complete the coolant bleeding - if it’s mandated by the individual manufacturer. It’s also a standard operating procedure for a mechanic to drain the coolant anytime replacing coolant system components; such as thermostat or coolant lines.

The radiator cooling fan relay is not one of those items that generally requires the fluid to be fully drained, but some mechanics will flush the radiator as a preventive maintenance service.

If you need to have further help having this checked, a certified technician from YourMechanic can come to your location to pinpoint any faults in the system.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • Question about thermostat replacement and radiator cooling fan switch replacement

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: Multiple parts replaced in Kia Rio, but still having trouble starting

Your charging system may have blown the main fuse to the charging system when it went bad. A new battery only allowed you to have a full voltage to start and run the vehicle, but the charging system will not...

Q: Engine cranks but won't start. VTM-4 engine light is on. OBD shows codes P0365, P0340 & P0132

You say you turned off the engine as soon as the vehicle was stopped. Does this mean the engine still runs? The VTM-4 light is for the traction control and you may have a problem with the system, which could...

Q: Does it have a crankshaft piston sensor

There is a technical bulletin, TSB 89-24-9, for a hard start after a short heat soak. The engine control module does not control ignition timing correctly when hot and thermostat lets engine get too hot. The recommendation would be to...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...