low coolant / add water?

Gas or diesel? If gasser, I would wait and see how the level looked after it warms up. If low and no coolant to add, I would put in distilled water...but only just enough till I get the right coolant to put in.

If diesel, I would wait till I started it next time and then see what the level does. If still low but visible in the overflow tank, I would wait till I had the correct antifreeze as the engine require special coolant.

Most diesels have over 10 gal of coolant...most gassers, just 6-7 gal and you can get that anywhere.

this is a 2003 Ford F-53 gas v10...

If you are not driving it, hardly matters.
If you are 50/50 water/AF and you don't live in the Yukon you can add some straight water.

Definitely add coolant. Do not add water.

Get coolant because you may need to top it off more again if you have a leak.

Always use coolant. Distilled water will dilute what is there, raising the freezing temp. Adding a little coolant will not cause any problem of increasing the coolant concentration. You don't ever want to run pure coolant but just topping off is far from that.

IB853347201 wrote:
Definitely add coolant. Do not add water.

I will support that if you live in the great white north.
But... Coolant level varies with heat and cold. It is very cold now. And though I know cold ENGINE lowers it. (From operating temps to ambient) I do not know how 70F to 0F affects it.. So long as there is coolant in the overflow tank I'd not add till A: Spring or B: next trip.. buy it. Leave a gallon on the driver's seat or nearby to reminmd you but don't add till VAROOM.

CC38EL wrote:
Gas or diesel? If gasser, I would wait and see how the level looked after it warms up.

I don't understand this. The level cold mark is the min level for cold engine. If you need to warm up to get to that level, you are low on coolant

You don't plan to drive it? Put tape on the tank, mark level and date. Then you can watch it.
Of course, the first step, with cold engine pull the cap from the pressurized part of system, be certain it is full. If not, get coolant, and refill. FIND THAT LEAK!
I can't stand under not having coolant on hand. I always buy the concentrate. If I don't have a MT jug, and don't know how low it is I use a small container to measure. 1 'cup' concentrate in system, then same of water 'til full. If it gets full the mix will be a little strong, not weak

Just make sure that you add the right coolant per your owner's manual. Not all anti-freeze mixtures are compatible and adding the wrong type can cause issues. I believe that Ford uses the green antifreeze but I would still verify to make sure.

Do you know what type of coolant is in the system? For model year 2003 F53 the coolant should have been changed about four times over the past 17 years.

Best not to mix coolant types if you can avoid doing. If you don't know then just use distilled water unless you are able to easily view the Northern Lights from the campsite the coach is parked at. If you can then try and determine what coolant was used and add with the same.