Hi all, My mk3 Focus 1.5 tdci as a problem with the cooling system, the temperature needle go up when driving an down when idling, The heaters get hot but the radiator an expansion tank is cold. I've changed the timing belt with the water pump also the thermostat an pressure cap ive flushed the various pipes to the matrix an the radiator still the same problem. Anyone got any ideas of the problem?

3 hours ago, Julian0476 said:

Anyone got any ideas of the problem?

What problem ?

It's a diesel, that behaviour is normal.

Hi, Well it's a behaviour that has recently started, it's only been playing the last few wks 

2 hours ago, Julian0476 said:

Well it's a behaviour that has recently started,

Would that be since the ambient temperature fell to typically less than 10^oC in the last few weeks ?

9 hours ago, unofix said:

Would that be since the ambient temperature fell to typically less than 10^oC in the last few weeks ?

I wouldn't say it's that, the temperature gauge as always stayed in one place at operating temperature until recently, an like I said the radiator is stone cold. I do appreciate the input though

1 hour ago, Julian0476 said:

I wouldn't say it's that, the temperature gauge as always stayed in one place at operating temperature until recently, an like I said the radiator is stone cold. I do appreciate the input though

If the radiator is cold, that means the thermostat is working perfectly, not leaking any hot coolant into the radiator before the engine gets up to temp.

Did you own this car last winter?

After taking it for a long drive the radiator an expansion tank is still freezing cold, No i bought the car in April 

37 minutes ago, TomsFocus said:

If the radiator is cold, that means the thermostat is working perfectly, not leaking any hot coolant into the radiator before the engine gets up to temp.

Did you own this car last winter?

After taking it for a long drive the radiator an expansion tank is still freezing cold, No i bought the car in April 

2 minutes ago, Julian0476 said:

After taking it for a long drive the radiator an expansion tank is still freezing cold,

Good, then the engine and cooling system is working just fine. It's not over heating and the coolant has not expanded in to the expansion tank since it's not hot.

You have a modern thermally efficient diesel engine designed not to waste fuel by creating excess heat.

35 minutes ago, unofix said:

Good, then the engine and cooling system is working just fine. It's not over heating and the coolant has not expanded in to the expansion tank since it's not hot.

You have a modern thermally efficient diesel engine designed not to waste fuel by creating excess heat.

Ok thanks for your input but it's only recently the temperature gauge has been going up an down, I'll keep an eye on it see if any other problems occur 

On 12/14/2024 at 5:01 PM, Julian0476 said:

Got it into a garage an their saying the after market NAPA thermostat is opening at roughly 83 an closing at 75 degrees, An they say that's ford operate higher temperature in the 90 plus degrees an advise to get a geniune ford thermostat. Any experience an suggestions? Thanks

 

1 hour ago, Julian0476 said:

Got it into a garage an their saying the after market NAPA thermostat is opening at roughly 83 an closing at 75 degrees, An they say that's ford operate higher temperature in the 90 plus degrees an advise to get a geniune ford thermostat. Any experience an suggestions? Thanks

1.0 EcoBoost stat is 91c.   

1.5 TDCI stat is 83c.

2 minutes ago, TomsFocus said:

1.0 EcoBoost stat is 91c.   

1.5 TDCI stat is 83c.

Ok thanks for your input time for a rethink then, an the garage had a focus in for an mot an that was as it should be temperature wise. 

2 hours ago, Julian0476 said:

Ok thanks for your input time for a rethink then, an the garage had a focus in for an mot an that was as it should be temperature wise. 

But, was that a diesel that had been left parked after having a run?

You are worrying about nothing, as was said earlier, you have a very efficient engine that is not wasting fuel by un-necessarily heating the radiator.

As long as the heater is hot inside the car, and it's not using water, be happy with it. 

Come the warmer weather, then you will see the radiator getting hot again.

1 hour ago, Alan G H said:

You are worrying about nothing

Perhaps they they don't get out much, or haven't got a TV ? 🤣

12 hours ago, Alan G H said:

But, was that a diesel that had been left parked after having a run?

You are worrying about nothing, as was said earlier, you have a very efficient engine that is not wasting fuel by un-necessarily heating the radiator.

As long as the heater is hot inside the car, and it's not using water, be happy with it. 

Come the warmer weather, then you will see the radiator getting hot again.

Under the same condition as the other focus, an as i mentioned in original post its only recently started being like this where the temperature gauge is fluctuating an the radiator an expansion tank is cold.

On 1/3/2025 at 11:25 PM, unofix said:

Perhaps they they don't get out much, or haven't got a TV ? 🤣

Maybe for you mate, But I have a loving wife we have good jobs nice home two kids. Life couldn't be better. 

Just an update had the thermostat changed for another oem part, An the issue is sorted temperature needle is constant an stable at all driving conditions even with the heaters on full.

3 hours ago, Julian0476 said:

Life couldn't be better. 

It's good to know that the sense of humour bypass operation was a complete success 🤣 

20 hours ago, unofix said:

It's good to know

Thanks, I'm guessing your one of these loners with no family or friends.