Weird issues last night. Loss of heat, very low idle.

[BrianDye]

Made a late night trip last night for some fast food, and as were sitting in the line waiting, I noticed my heat was blowing out ice cold. (rear was as well)

My idle was also very low, so low that the light were dimmed a bit because the alternator wasn't spinning fast enough. If I guessed, (since I forgot to look at my ultragauge) I would say probably 500 RPMs maybe less and a lot of vibrating but drives just fine.

Once we took off, the heat worked perfectly fine again. The rear took about 5 minutes and then worked great again. When we were back on the road, it was still turned off, and when I turned the heat back on high, my temp gauge dropped by about a centimeter and slowly rose back up.

I haven't checked the obvious the, like low coolant or trapped air, but has anyone else had that before? The low idle started the same time I lost heat. It's never idled low before.

I'm gonna check the coolant and hoses today as well as replace the fuel filter, at 85k I'm sure its stock and needs to be replaced.

 

[BrianDye]

Just went out and checked, my coolant is low, but I'm at a loss of what kind to add. The owners manual states some special Orange Ford coolant, which Autozone does not carry (only place open today)

But now that I'm thinking back, when I was power washing my undercarriage after some off roading, there was some bright green fluid on the driveway towards the rear leading me to think there's a leak related to the rear heat setup. It was bright green like normal coolant, so I'm wondering if that's what's in there?

I know on my Edge, it called for the gold coolant which ended up causing clogs in the heater core and the dealers were instructed to do a heavy duty flush and then refill with green coolant. Wonder if the Explorers had a similar issue?

 

[Flag Gibby]

I have been using Prestone Extended Life 50/50 prediluted mix and it is compatible with what is already in the system and acceptable for use in our vehicles. The original motorcraft gold stuff (what is called for in this generation explorer, never read a spec. calling for DEX/orange? coolant) is a gold/yellow color with bittering agent in it to keep animals from wanting to drink the stuff if it gets spilled on the ground and not orange like you mentioned in your post. If you really want exactly what goes in there then you want to use Valvoline Zerex G-05. However, both the Zerex G-05 and Prestone Extended Life are HOAT coolants.
Also, it does sound like your heater lines at the rear HVAC unit could have a leak and if your coolant is green in color then just use the Prestone.

 

[BrianDye]

I'll probably top off with the Prestone for now, and the next few days whenever it gets above 30 degrees track down wherever it's leaking from and then do a full drain and fill.

There are way too many types of coolant nowadays!

 

[Flag Gibby]

Really there are only three types of coolant, just a lot of different colors. There is the inorganic acid technology (IAT), organic acid technology (OAT), and hybrid organic acid technology (HOAT). It used to be that you could identify what the coolant type was based on color, but that really is not the case anymore.

 

[Flag Gibby]

I should correct myself regarding Presone Extended Life. It is an OAT and not a HOAT since the MSDS on it lists 2-Ethyl Hexanoic acid as being present at less than 1%. That is the difference between an OAT and HOAT, an OAT contains 2 ethyl hexanoic acid and a HOAT does not.
Presone Extended life primary contents: ethylene glycol @ 80-95%, diethylene glycol @ 0-5%, and other additives @ less than 1% total (water, 2 ethyl hexanoic acid, neodacanoic acid
Zerex G-05 primary contents: ethylene glycol @ 50.4%, diethylene glycol @ 2.5%, sodium benzoate @ 1.4%, and disodium tetraborate anahydrous @0.8%

 

[BrianDye]

Wow, thanks for all that info, I appreciate it!

Topped off with some of the 50/50 Prestone, my overflow tank was empty, and the radiator took about 1/3 of a gallon. Changed my fuel filter out as well, it was like thick coffee. Nasty!

After a few primes of the fuel pump, the thing fired up easier, quicker and smoother than before. Haven't actually driven yet but everything seems to be smoother now. Idle is a bit better, though not where I'd like it. (Feel like the member "Aldive" [R.I.P.] chasing a perfectly smooth idle! Lol)

I saw another post someone made earlier this year about leaking coolant in the rear of the vehicle which is where it came from when I washed the undercarriage, it ended up being the rusted hose clamps to the rear heater core which he said was very easy and cheap to fix. Hoping that's my issue as well.

It's nice not knowing I'm crazy, every time I talked to coworkers and friends about my mysterious leak which was coming from the rear, they looked at me like I was crazy. I wasn't sure, but guessed there was another heater core back there for the rear heater, looks like I was right.