Mysterious disappearing coolant...

[metheguy]

I have a 2012 Ford Fiesta with 1.6l engine, which in the first 3 years of its life lost a pint of coolant. Should I be concerned?
My 1999 Ford Ranger is also losing a similar amount of coolant. (and my John Deere tractor too! ###?)
The Fiesta is just out of warranty , the dealer "forgot" to note that they added coolant while it was still under warrantly and they cannot find a leak.
Is this a common problem with this engine? Is there a common place to check? The coolant is going somewhere.
thanks

 

[Swanp Gas]

If you are sure you can't find a leak then you need to check your oil to make sure it's not contaminated.

Google "coolant in oil" and you should get some results on how to do this.

 

[Setec Astronomy]

I don't think a pint in 3 years is anything to worry about. What is your factory coolant change interval on those vehicles?

 

[Mike Honcho]

A pint in 3 years is merely evaporation. Get yourself something like Mini UV Ultra Violet LED Flashlight 395nm for ID Passport Authentication | eBay. UV flashlights are cool! They make forged documents, body fluids (like pet stains), counterfeit bills and coolant leaks light up bright green! Check for coolant leaks when it's pitch dark to maximize the effect. Most radiators now have plastics ends that are sealed and crimped to the aluminum center core. I've had to change out 3 radiators in 2 different cars because the seam failed where the plastic was crimped to the aluminum. It was such a small leak at the top corner that it would evaporate before it would puddle under the car. The UV flashlight was the only way I could find the leak.