Ever since my coolant tank was replaced the ENGINE COOLANT LOW warning displays for a brief minute after a cold start. Otherwise no warning.

Searching the forums I suspect the coolant is in need of a top-off or a sensor, magnet, switch could be to blame.

I want to start with the obvious -- is the tank indeed low? Owner's manual says there's a Max Fill line inside the tank visible after removing the cap. After careful inspection I've yet to find the Max Fill line.

How full should the tank be on a cold engine? I've attached a couple pics of my current coolant level on a cold engine.

PS - The underside of the cap has a FoMoCo imprint so I'm inclined to blame Ford for this notorious issue in our X350s!

 

Split the difference. Add enough to halve the empty space. Chances are your problem will go away. May return if you have a slow leak. Keep an eye on it.

 

From the pictures, yes, absolutely your coolant is low. From the outside the tank should appear completely full. When cool, if you open the cap and look inside, you will see a stepped plastic marker for min and max. The coolant should come nearly to the top of the marker. Start by topping it off, then check it regularly for a drop in level...this would indicate a leak.

 

Here is a picture of the max fill step.

 

Thank you Lagonia, Drb007, and trosty.

The car ended up taking a cup of 50/50 mix. Not sure if the original tanks have MIN and MAX imprinted on the step, as shown on the illustration in the owner's manual, but my new one doesn't. Nonetheless I've topped it up and learned something new.

Thanks again.

 

Get a good torch and look around the front of the engine behind the radiator for the "glint" of coolant when its cold. These things are difficult to see in daylight because the eye is overwhelmed by the light and any glinting coolant is not seen, (unless it is leaking in bucket loads !!). Small leaks can become big ones if a plastic coolant circuit part splits. On my V6, there was no evidence of a leak at the header tank, but it was split where the vent hose connects onto the nipple. The other end at the water rail was seeping and about to let go, (it actually did when they took the water rail off to replace it). However the V8s are different, so this latter problem may not apply

 

If you are good with a wrench, you may want to proactively pressure test the cooling system and see if indeed you have a leak. Lot's of threads there but take a look here:

Radiator Leak

 

I forgot to mention that one should look around with a torch in the dark for wayward coolant. The eye, adjusted to the dark, will then pick up the glint of small leaks much more easily.

 

When Fraser says a "torch" he means a flashlight. Good thing I watch a lot of BBC America!

 

Hmm. I never knew there was a max level. I've always put in as much as it will hold when I change the fluid. Always figured it would overflow and stabilize after a few runs. I'll have to look for the mark next time...although my way has worked for almost 10 years.