[tobywun]

Scenario: Drove my '13 Bull about 100 highway miles. Get to the city and while waiting in Walgreens drive thru for the meds I confirmed were ready the day before but now were oddly not ready (that story isn't related to my current vehicle issue), the red temperature light flashes along with the "this is going to cost you some serious bank" audible warning. Me, in a near panic, revved the engine knowing that doing so had zero effect on cooling. Be that as it may, the light disappeared oddly enough. I grabbed my now ready meds and gently drove the Bull to a nearby family members house. Ok it was my mom's place. A little backstory. A couple of years ago I had to have the water pump replaced. I was way out of town, and it cost... I'll just say a lot. Back to present day. So, I got to my mom's, pop the hood and just look around as if I know what I'm doing. Good news at that moment was I didn't smell my bank account losing funds, aka I didn't smell antifreeze. I didn't see any leaks. No spray anywhere either. Basically nothing out of the ordinary. I let the beast cool for a while then I popped the coolant reservoir and it was Sierra Desert dry, not a hint of moisture. Long story even longer, I fill it with what's avail; garden hose water and leave the cow overnight. Post good night's sleep I checked the tank in the morn, and fluid was holding. I ran the pup in the yard to temp, and didn't see any leaks. I took it for a ride around town, all was good. Drove it the hundredish miles back to my crib, no issues. Checked the tank after it cooled, and the level was fine. Never found anything leaking, car always ran fine, no interior leaks, oil is black as...well used oil, and no tail pipe smoking. Anyone out here have a clue?? I plan to pressure test and flush, but other than that I'm stumped.

 

[kekaye56]

I would definitely do a pressure check. If no external leaks are detected then look internally (I.E. head gasket).

 

[HaarFager]

Here's something you might check, because it happened to me recently. My 1996 Ford Taurus wagon kept losing coolant, but only about every month and a half would it be low enough to have to add some more coolant into it. It must have been a real slow leak somewhere, but I couldn't find it. One day I was driving along and my heat gauge went up and got real high, real quickly. I pulled the car over to the side of the road and popped the hood. I saw a flat, approximately 1 and 1/4 inch stream of water shooting out the side of the overflow tank, toward the fender direction. It must have started coming apart at the seam on the side of the plastic overflow tank and it finally blew. Needless to say, this $21 part cooked my engine. It's such a shame that a part like that can go so quickly and ruin your engine in such a short time. I was heartbroken, to say the least. I guess it warped the heads and now I'll have to get another engine for it. This was just a suggestion to check. Hope it helps before it's too late.

 

[Gtech1]

I know from the same experience that the reserve tanks on Taurus's and most likely Sables too, over time the constant expand and contract over years of driving them does weaken them at the seams. I recently had this happen to my 2000 Taurus. Luckily I didn't immediately have to buy a tank since I have a 1998 in the garage with a broken engine. Quick swap (though the one I took off the other car has a crack in it that's not leaking yet). I did buy one from RockAuto. And luckily the fluid level sensor in the tank worked. The other one didn't.

 

[Jeff K]

^^^^ failed surge tank is a common problem on the G3's. Hope you didnt buy the Dorman replacement tank, as it will likely fail again. Fork up the $$ for the Motorcraft tank. I have never heard of a surge tank failure on a G6.

 

[Hornswaggle]

I was having trouble finding a slow coolant leak on one of my cars so I tried the UV dye and after a short drive shined a black light around and found it right away! It was a loose clamp leaking onto the top of the engine (duratec) only when pressurized and the coolant would evaporate on the hot engine so would never pool or reach the ground. I got the small bottle of dye in a kit that included the black light and some tinted glasses, can't remember what local parts store had it but could have been AZ. Highly recommend this if you can't find external leaks.

 

[taucor0315]

On YouTube , there is a vid on doing a coolant pressure check, on a late model Ford Cyclone V6. The video shows the coolant coming out of the water pump weep hole , when under pressure.

Check to see if BOTH cooling fans are running. A cheap OBD II scanner that gives live temp readout can give you a clue of what the actual coolant temperature is. Could be a faulty temp sensor? If the reservoir was bone dry, coolant must be leaking from somewhere & low coolant could have caused the overheating condition, depends on how low coolant was. I like the UV dye in the coolant test too. Same for the coolant reservoir theory. How long was it since a coolant F & F? On these 3.5 V6s it good to change the oil sooner than most cars , because that water pump problem, same with the changing the coolant itself. I do the coolant 3 years or 36K miles.