2014 Ford Transit Connect 2.5L Gas with Coolant Leak

[TC2014]

Hi All,

Long time runner of a 2014 Ford Transit Connect 2.5L naturally aspirated Gasoline Engine

Not long ago, perhaps a year ago (2023) during the winter-time, I had loss of heat unless I was either revving the engine or driving it.

Upon an inspection of the coolant reservoir, I denoted it was low on coolant. A quick top-up of less than 800ml or ~20oz of pre-mixed formula

and the levels came back up to what the coolant reservoir indicated was a filled system. I was then able to get heat any time the engine was running.

 

Fast forward to this year (2025) and now my coolant is yet again low... I still have the pre-mixed jug of coolant which I did a top up with but I suspect whatever leak I had initially has now degraded to a worse point than what I initially had. I've basically had the same symptoms as last time, coolant indicator on my dash says she's hot but I only get hot air if I have the engine revving higher or I'm driving. I've already done 2 top ups from what I thought I needed although it was parked in such a way that perhaps the angle made my understanding of how much filling I needed to do was incorrect.

I do not see any kinds of obvious leaks which would be from the coolant system, at least from what I can tell. Before I go down the path alone to check out the various possibilities, I was wondering if anyone else has run into this issue before and if so what they found the problem was.

My mechanic denoted that he has run into this issue in the past and used a "radiator leak stop" with some kind of success but I do not have a lot of faith in leak-stops providing me what I need in terms of a proper fix. His guess was something to do with the Head Gasket, which he claimed would easily be $1K-$2K between parts and labour. Personally, I have seen some head gaskets available online, I'd be more apt to take a crack at doing it myself provided it wasn't too complex. Which leads me to my last query to know if anyone else has done the head gasket repair themselves and how they went about doing so.

[G B L]

Is the engine running different than it has in the past? Is there any sign of contamination in the oil? If the answer is no then a code scan is in order. Then a static pressure test of the cooling system would be next. 

How many miles are on the TC?   The Head  gasket replacement will be a sizeable job Involving  the front engine cover and cam shaft timing chains , Intake and exhaust manifold removal.  It could include a valve job for the head .

 All the hoses and water pump need to be checked  and the radiator end caps need to be looked at. If nothing obvious is found 1/2 a bottle of this won't hurt and could save the Day.  I have used this as a permanent fix more than once!

Good luck and update us when you can.