Hi All,

I recently picked up a Focus 1.6 TDCi, 14 plate. Apart from a few minor issues, it's been great for the price. However, the thermostat went the other week (putting the heating on meant engine temp went right the way down). I got it fixed under the dealer warranty. However I'm not sure if the correct temperature has been set.

It goes up to 80/81C (I'm measuring via the hidden menu on the trip computer and not the temperature gauge) and then goes down to 75, back up to 80 before it evens out at around 79/80. At this time the temperature needle is going from 1/4 to 1/2 before it settles at just under a 1/2.

What is the actual operating temperature of this particular engine? I was always led to believe it was around 90C, which made me think the thermostat had been set to open too early. If so, is there any harm in it operating at 80 once its up to temp? Do i need to get it looked at again? Or am i just being paranoid and this doesen't matter at all? Thanks

The temperature of the stat is fixed, it's not something that can be adjusted and it's not likely to be degree perfect.

They're designed to open at 83c so yours might be one or two degrees lower than perfect but it's close enough tbh.

 

Mine runs at 82 C light load to 92 C heavy load

You can’t be sure of the accuracy of the temperature sensor. Just because the hidden menu says a certain temperature it might not be exactly that

Mines from an extra accessory sensor and gauge. But normally within 1c of the ford Dash one

 

I have a 2014 1600Tdci Focus. The engine seems to take some time to warm up but when the Temp gauge does register it only initially goes to approx 1/4 up the scale.. It stays there for a few seconds and then drops straight back to the bottom of the gauge. It stays there for sometime but then gradually climbs eventually to approx 1/2 on the scale. Is this correct. I always thought that the thermostat should open gradually to maintain the engine temp once reached. It seems to me that it is just opening fully thus allowing all the cold water still in the radiator to run straight into the engine block causing a sudden drop in the temp of the block. Rob from Stafford.

It sounds about right for a modern diesel engine. Even in the middle of summer they time to warm and normal operating temp seems to be around 80 to 85C (not quite half way on the gauge).