Internal Heating Problem

[craigh]

Hi everyone, your help would be much appreciate. I had a coolant dump on my 54 plate D4D yaris and since then it has been taking ages to warm up. I know that they take a while to get the interior warm but now it takes even longer. It also stops blowing warm air when the engine cools slightly; warm under load climbing a hill, blowing cold going downhill the other side. Is this possibly due to a damaged thermostat from the coolant loss? I have bled the cooling system multiple times incase of an airlock.

[CPN]

Sounds like the thermostat is jammed fully open for whatever reason. Did you replace the Coolant yourself? Did you check the thermostat during this process? What did you replace the Coolant with?

[craigh]

The coolant was replaced by the AA and by a garage and topped up by myself a few times until we found out why it was losing coolant. The coolant was replaced with proper antifreeze/coolant. The AA checked to see if the interior got warm and monitored the pipe from the rad but didn't really check the stat. Would it be the safe option just to replace the stat?

[CPN]

That would remove all doubt in that direction, yes. Hopefully an easy fix?

[craigh]

I'll probably just do it then. As you say, hopefully an easy fix!

[Mike169]

Hi, just take the stat out and look at it to see if it has opened up and you can test it by placing it in a kettle of water slowly bring it to the boil and see if it opens.

Also when it is all back together leave the engine running for say 15 mins, long enough for the engine to warm up and feel all the hoses the best you can and all of the radiator fins to check it is all warm all over.

Last thing, you can fill the cooling system pouring water down the top hose, take it off first at the easy end, leave the rad cap off and let it overflow that way.

All just different things to try, let us all know how you get on.

Mike.