Thermostat replacement

Iced-T · June 27, 2017

Hi ..

I have just noticed that the thermostat on my car has stopped working. I want to remove it and get it replaced some time this week.

The only issue is that I just filled in new coolant into the system (last week). Will I lose a lot of coolant when I remove the thermostat housing?

Or should I drain the radiator into a bucket .. and just pour it all back in?

Vehicle details : Lancer C12 , 4G15 engine.

Thanks.

Davy · June 27, 2017

The system is filled with coolant, so the moment you remove the thermostat housing or the hose that connects to it, there'll be coolant spilling everywhere in the engine bay which will lead to a big mess.

To avoid this, use the radiator drain plug and drain some of the coolant until the thermostat area is free of coolant. You wouldn't have to drain much because the thermostat sits right at the top of the loop.

Iced-T · June 28, 2017

On 6/27/2017 at 9:49 PM, Davy said:

The system is filled with coolant, so the moment you remove the thermostat housing or the hose that connects to it, there'll be coolant spilling everywhere in the engine bay which will lead to a big mess.

To avoid this, use the radiator drain plug and drain some of the coolant until the thermostat area is free of coolant. You wouldn't have to drain much because the thermostat sits right at the top of the loop.

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Thanks, I will keep the system dismantled until i search for a replacement thermostat. should be about 3 or 4 hours. I am hoping this would not affect the properties of the coolant water mixture.

Also will I require a gasket sealant to put on the thermostat housing when I close it up again?

Edited June 28, 2017 by Iced-T

Davy · June 28, 2017

On 6/28/2017 at 9:13 AM, Iced-T said:

Thanks, I will keep the system dismantled until i search for a replacement thermostat. should be about 3 or 4 hours. I am hoping this would not affect the properties of the coolant water mixture.

Also will I require a gasket sealant to put on the thermostat housing when I close it up again?

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There should be a gasket between the housing and thermostat already. Be careful not to damage it when you take the housing out. So you can reuse it. I'd recommend using a matching stamped gasket as opposed to using gasket maker if you want to change it.