Why did a low coolant warning not come on? Don’t mk2.5 focus have a warning? It was literally almost empty but my temp stayed normal which is strange plus I’ve had air con on lots and didn’t even notice any change. Is there any obvious causes of this on the focus other than usual split hoses and cracked radiators etc? I had my cam belt and water pump done the other month and I botched after the coolant had dropped so went back to the mechanic and he topped it up again. I think after that it went down slightly again and I topped it up again and put a new cap on and it seemed ok and then today I’ve seen it’s almost empty. 

5 minutes ago, Jason87 said:

Don’t mk2.5 focus have a warning?

No they don't. If you look at the reservoir, there's no electrical wires/sensors hanging off it.

6 minutes ago, Jason87 said:

but my temp stayed normal which is strange

Not strange at all. As long as the bottom pipe has coolant going into it then the system won't overheat as there's enough in the engine.

7 minutes ago, Jason87 said:

I’ve had air con on lots and didn’t even notice any change

You shouldn't notice any change. The aircon is separate to the engine cooling system.

So it’s either the seal wasn’t tight enough when they changed my water pump or it’s just leaking somewhere due to age. It’s never dropped  that much before though. I’ve filled it up again and left engine running and it’s not dropped so I don’t get what could cause it to lose that much but not do it again once I fill it up?

I don’t know what engine you have. I had a1.6tdci which leaked slightly from the plastic thermostat cover. Took me a long time to find. I put radweld in, after a while it leaked again but the red staining from the radweld led me to where the leak was

2 hours ago, Jason87 said:

seal wasn’t tight enough when they changed my water pump

Did the expansion tank get topped back up after a couple of days when the pump was changed ?

40 minutes ago, unofix said:

Did the expansion tank get topped back up after a couple of days when the pump was changed ?

The mechanic topped it up then I think I topped it up about twice. Don’t get how it was so empty this time though after only a few weeks 

I hope you are using Ford Coolant and not just tap water. 

After the pump was replaced was the system refilled with a 50/50 mix? 

1 hour ago, unofix said:

I hope you are using Ford Coolant and not just tap water. 

After the pump was replaced was the system refilled with a 50/50 mix? 

I’m not sure what they used, assume was some coolant. I’ve just filled it for now with tap water. Tap water is ok isn’t it as long as not freezing weather?

8 hours ago, Jason87 said:

 Tap water is ok isn’t it as long as not freezing weather?

I was always told that tap water is not good enough because it has the potential to 'rust' the engine internals - you need an anti freeze which has chemicals in it to inhibit rust. However, I'm an old man now, and that advice was given 40 odd years ago, and maybe engines are built differently now LOL

My understanding is that you should use antifreeze as it contains corrosion inhibitors, but I’ve put normal tap water in my card when they need topping up. I know that’s not so good when winter comes around as I have diluted the antifreeze in there so the freezing point won’t be so low. Some cars these days have oil coolers which are cooled by the radiator water and there have been cases of these corroding inside so the coolant gets in the oil, so that has made me keener to keep a reasonable level of antifreeze in there.  And then there’s the issue of mixing different types of antifreeze which is quite complex. Some types I believe are not effective if mixed due to incompatible chemicals in them

Modern anti-freeze includes rust inhibitors so you can mix it with tap water.  Though the ratio is probably well off with the amount that's now been added.

1 minute ago, isetta said:

... And then there’s the issue of mixing different types of antifreeze which is quite complex. Some types I believe are not effective if mixed due to incompatible chemicals in them

I use this Prestone to top up (Often on offer in Tesco), compatible with all types of anti freeze...

And if buying antifreeze, note that some bottles are already diluted, they make out they are doing you a favour ‘premixed’ ‘ready to use’. It’s a con , you are paying for less antifreeze with a load of water added. 

1 minute ago, isetta said:

And if buying antifreeze, note that some bottles are already diluted..

Always amazes me that very often, 'screenwash' is also sold pre diluted! Why on earth would you buy 'water'!

If you added water at some point then you need the antifreeze concentrate to compensate for that, ready to use stuff won’t compensate for the water you added as it’s already diluted with water

I still don’t know why it lost that much Coolant but hasn’t lost any yet after a another drive. To lose that much I thought it would have to be  an obvious leak?

And……. I bought some antifreeze concentrate this year, seemed more expensive than I recall, has it got up a lot? Think the best I could get was 7 or 8 quid for one litre

1 minute ago, Jason87 said:

I still don’t know why it lost that much Coolant but hasn’t lost any yet after a another drive. To lose that much I thought it would have to be  an obvious leak?

 

Have a check to see if you driver side mat is damp, if it is, could be a heater matrix issue...

I wouldn't say it's a con, saves messing about trying to work out how much you're adding to create the ratio...especially if you don't have a bath with taps and have to try and fill tiny bottles in the sink instead.     I tend to buy ready mixed screenwash as well but I don't use much of it so the extra cost doesn't bother me.  If you look at the Halfords 'concentrate' you're actually paying more for the same stuff as it's only the same frost protection when undiluted!!

2 minutes ago, TomsFocus said:

I wouldn't say it's a con, saves messing about trying to work out how much you're adding to create the ratio..

Tom, just checked Halfords, 5l of concentrate is £5.49, 5l of premix is £4.79 - I'm tight enough to mix it myself at home with free tap water LOL

10 minutes ago, StephenFord said:

Have a check to see if you driver side mat is damp, if it is, could be a heater matrix issue...

That’s a horrible job isn’t it? I did that on my 406 and butchered the dash lol

10 minutes ago, Jason87 said:

That’s a horrible job isn’t it?

Yes it is LOL The most common fault is the failure of a £3 'O' ring, though the job can be done without 'butchering' the dashboard, as long as you can work upside down, are pretty agile, or can employ a mechanic who is LOL

13 minutes ago, StephenFord said:

Tom, just checked Halfords, 5l of concentrate is £5.49, 5l of premix is £4.79 - I'm tight enough to mix it myself at home with free tap water LOL

But then you'll lose the frost protection...  The 'concentrate' is only good to -10 if you don't dilute it!  Now that's a con... 

 

1 minute ago, TomsFocus said:

But then you'll lose the frost protection...  The 'concentrate' is only good to -10 if you don't dilute it!  Now that's a con... 

 

I've never 'diluted' it directly, just pour it straight into the reservoir and guesstimate the whole process. Never had an issue in 40 years LOL

21 minutes ago, StephenFord said:

I've never 'diluted' it directly, just pour it straight into the reservoir and guesstimate the whole process. Never had an issue in 40 years LOL

I think you're missing the point here lol.  

If you buy the pre-mixed berry screenwash, expecting it to protect to -10, just pour it in and it'll do that...

If you spend more on the concentrate, expecting it protect to -10, and dilute it 50% it's then only good to -4c.  But they still write '-10' on the front.  You'd have to use it neat, costing more than the ready mixed, to get that -10c protection.