Having a weird issue regarding coolant loss.

Firstly, I had last checked the oil and coolant 3 weeks ago as part of some general checks since we are starting to get in to the cold weather. Everything was sound, all fluid levels good and the car had only been fully serviced in July.

Cut to a couple of days ago when I was driving I noticed that the heater wasn't working well, pushing only luke warm air at best when idle then proper hot air when moving. Pulled into a shop ASAP and popped the bonnet. The coolant expansion tank was completely empty, so bought some fluid and filled it up and drove home (very short distance) and left it overnight as it was too dark to check anything at the time. I checked the oil again to and it absolutely reeked of petrol and seemed super watery (even more than how watery the oil is for these models).

Next morning I checked the level again, it had dropped a bit to between Min + Max as I would have expected, so topped it up again then started the car up and took it for a mile run to get it to normal op temperature. I then left it running to check for any potential leaks. Nothing at all. Got it into a garage the next morning and they did pressure checks etc and said everything seemed fine and there were no leaks that they could spot. They said the oil seemed fine but I got them to change it anyway for my own peace of mind.

Now the blower eventually runs warm at idle, but it's not reaching the really hot temp I know it should and previously did. Tried running from cool with the expansion tank cap off to help move any potential trapped air but it still definitely runs significantly hotter at speed. The expansion tank level hasn't moved since, but I haven't done a lot of driving outside of getting back from garage and the test run for blower heater.

Really confused to what's happened over 3 weeks for it to completely disappear like that. Any ideas?

Starting at the beginning: Are you using genuine Ford coolant and is the mix 50/50 ?

If we accept that there are no leaks, and the pressure test also confirmed head gasket was ok then the only other place the coolant can have gone is out via the vent/filler cap. Or there has been an air lock in the system which has now gone and hence the coolant level dropped.

I would expect your heater to be cooler when just at idle than when moving, I know mine is at this time of year.

At this moment I would just keep a close watch over the next couple of weeks before jumping to any conclusions.

 

 

46 minutes ago, unofix said:

Starting at the beginning: Are you using genuine Ford coolant and is the mix 50/50 ?

No clue what brand what was in it prior to this, but the emergency fill was with this Bluecol'u' Clear Anti-freeze & Coolant https://www.ebay.co.uk/itm/402795607633 (it was all the shop had available). Obviously not ideal since it's meant to be more of a top-up than 3/4 of the coolant 😅. I'll drain the tank and put proper stuff in when I get the chance.

 

1 hour ago, unofix said:

the only other place the coolant can have gone is out via the vent/filler cap.

So there is no residue/gunk around the cap or reservoir bottle and there's no hissing in or a round it when the car is running. What vent do you mean?

 

1 hour ago, unofix said:

Or there has been an air lock in the system which has now gone and hence the coolant level dropped.

I would highly doubt this was the case. There was no obvious issue with engine temp (at least the one reported on the dash) nor the blower before this. An air lock of 1.5 litres of coolant would have been very obvious in the 2000 miles I've done since last service.

 

1 hour ago, unofix said:

At this moment I would just keep a close watch over the next couple of weeks before jumping to any conclusions.

Yeah I will be keeping an eye on it every day now. Thanks for your help/suggestions!

Take it to ford, I have a 2012 ford focus. 1.0l ecoboost, and had the same problem, took it to ford, they fitted a new engine etc in my car, as this is a recall, all fitted, no cost to me