Recently got a ford focus 1.8tdci 115 zetec s focus.

It has been remapped to approx 150bhp

The temperature seems to hover around 60c degrees normally which seems low to me, weirdly under acceleration it goes to 90c then drops back off when up to speed to 60c again.

so far thought it might be the thermostat sticking open.

Any ideas folks what it is?

At 60c the stat should be fully closed and the radiator stone cold.  If you feel the radiator after a drive, that should tell you whether the stat is stuck open or not.  

Odd that it rises to 90 under acceleration though, sounds like it may not be bled properly and air in the system is giving false readings.

On 5/7/2023 at 1:27 PM, TomsFocus said:

At 60c the stat should be fully closed and the radiator stone cold.  If you feel the radiator after a drive, that should tell you whether the stat is stuck open or not.  

Odd that it rises to 90 under acceleration though, sounds like it may not be bled properly and air in the system is giving false readings.

Thanks for your reply. 

I have attempted to bleed it and I have put some rad flush in it and it seems to be working much better, I was wondering is the radiator drain plug plastic and located under the passengers side? And if so which way do I turn it? Clockwise or anticlockwise? 

 

2 hours ago, Roach said:

I was wondering is the radiator drain plug plastic and located under the passengers side? And if so which way do I turn it? Clockwise or anticlockwise? 

Yes.  If the radiator is original then the drain plug is plastic with a cross-head on the passenger side.  Anti-clockwise to open.

If the radiator is aftermarket, they don't always have drain plugs.