Last weekend my girlfriend picked up a 2003 Mountaineer with the 4.6 V8, 153k miles on it and decent shape. Coolant level is below cold fill but the dealer or previous owner filled it with Orange coolant and possibly did not fill it all the way as the vehicle has auxillary climate controls as well which uses 20 quarts vs 18.6 quarts. From my understanding orange coolant is the dreaded GM Dex-cool which is known to become mud like when air is introduced, effectively killing water pumps and engines...at any rate I've read that Ford recently went to a similar blend but haven't confirmed this.

I would like to top off the system but I would like to know which coolant should get for now. Should I just get whatever bottle says Dex cool on it and then flush the system when it's a warmer day? Motorcraft coolant is not sold at any main retailer outside the dealer's around me.

 

I always get the store brand or prestone, usually pre-mixed, that says "for all makes and models" on the bottle.

 

Yeah that's what I usually do but I'd rather not mix green with orange as it could cause issues.

 

GM and the Europeans started using the ORANGE several years ago. GM calls it DEXCOOL... FORD started converting to the ORANGE in 2011 with some models and probably all now use that. The call it EXTENDED ORANGE or something like that.. It is the same as DEXCOOL. Go to Wal Mart and look at the DEXCOOL bottle on the back label and you will see it meets the FORD SPEC . I forget the spec number, but will post it later. ......... You should not mix the ORANGE with the yellow or green. If there is ORANGE in the old Explorer, it was not original... I hope it was flushed out good... FORD did not convert years ago because GM had trouble with gaskets and rubber parts turning to mush as you said... All NEW FORD motors have O-rings and gaskets that are compatable with the ORANGE... I would not say that 2002 is fully compatable.

 

FORD spec M97-B44-D is the new ORANGE spec for NEW cars and trucks. PRESTONE DEXCOOL meets that spec...We use it in our 2014 Taurus.

 

Well fortunately I'm good now and topped off. Thanks for the help. This summer it'll be fully flushed out and it'll be green. I don't trust DEXCOOL after seeing first hand multiple water pumps fail or come in for water pump replacement.

 

The yellow extended life coolant is standard for the 2002 RXP... Green is OK, but yellow is somewhat better........ Just make sure you flush the DEXCOOL out a couple times. Don't leave any residue in the system..... Im not sure the problem is a reaction between the coolants.. I think a lot of it is incompatability of the DEXCOOL with older gaskets, seals, rubber parts, even metal parts.

 

MOTORCRAFT PREMIUM GOLD ENGINE COOLANT - SERVICE TIPS (TSB)
http://www.revbase.com/BBBMotor/TSb/...dPdf?id=116643

Service Coolant Usage Chart - Motorcraft
http://www.motorcraft.com/servlet/Bl...lob&blobkey=id

Motorcraft® Engine Cooling System Products and Engine Coolants
https://www.fordparts.com/Products/C...-Coolants.aspx

VALVOLINE™ ZEREX™ G-05™ ANTIFREEZE / COOLANT
Valvoline? ZEREX? G-05? Antifreeze / Coolant : Product Catalog - Valvoline®