Overheating Toad!

[OldBlackWater]

I had a puzzling experience with my Ford C-Max Energi toad on the last day of my return trip from Yellowstone to Texas yesterday. After five hours on the road through the Texas heat (mid-to-upper 90s), we parked in a cement (i.e., not blacktop) mall parking lot to walk to a Whataburger, since that's what Texans must do when almost home from a long trip. After getting our fast food burger fix and returning to the motor home, I notice fluid leaking from the engine compartment of my C-Max. After opening the hood and whispering a couple of expletives (the kids were within earshot) to make my burning hands feel better, I see the fluid inside the coolant reservoir boiling and bubbling out onto the ground.

Before approaching the car, I had noticed that the fan motor was running in an attempt to cool itself down. I also noticed after starting the car that 12 miles had been added to the odometer, as if maybe on the road somewhere it turned itself on to try to cool down (or maybe that's just a totally unrelated quirk of the car).

My guess is that the engine compartment took on a lot of heat from the hot roads and from my motorhome, then baked some more in the hot sun for 30 minutes while we enjoyed the deliciousness of oversized burger patties on buttery toasted buns.

Has this ever happened to anyone else?

[jsmart]

We have a 2014 Ford C-Max hybrid that we tow behind our MH. I'm teaching DW how to hook up the toad. Noticed it's easy on our C-Max to go past ACC when turning off the engine. DW had it in "ready to drive" once, fortunately, I saw it before we took off. Sounds like everything is OK with your C-Max?

[willald]

OldBlackWater wrote:
Well, this is embarrassing. When I did a quick subtraction of odometer readings after noticing there was even a difference, I got 12 miles, but after looking at my iPhone photos (I took pictures of the dash display since I didn't have a pen handy), I see that it's actually 312 miles, which is about how far I drove that day. So it must have been in "Ready to Drive" mode the entire time and didn't get enough airflow to keep cool. Fortunately, no damage was done.

Well, at least this solves the mystery, and now we know what happened. Thanks for posting back, even though it was a bit embarrassing. I was curious about this one. Glad to hear that no damage was done. 🙂

I might just leave it off altogether (i.e. not in Acc mode) to help avoid this in the future...

..Yeah, like already said, I would be very cautious about doing that. You don't know the specifics of why Ford instructs you to leave it in ACC mode, what electrical systems they may WANT to stay on when being towed that you may be shutting off.

Nearly everything with these hybrids is electrically powered/controlled. I'd really hate to think that something like an electric lube pump for the transmission would get shut off when towing, if you didn't leave it in ACC mode.

That was why I chose to install a charge line, and just leave it in ACC mode and not mess with pulling fuses when towing. These Ford hybrids are pretty complicated machines, haha.

Unless you could get a good, thorough knowledge somewhere of what systems are on and what systems are off when in ACC mode, I'd be very hesitant to try shutting it completely off.

By the way, I did install a charge line. It works great, with and without the engine running!

Good, that's definitely very important for these hybrids. It pretty much eliminates the chances of you ever running a (12 volt) battery dead. 🙂

[Vulcan_Rider]

OldBlackWater wrote:

I might just leave it off altogether (i.e. not in Acc mode) to help avoid this in the future.

You need to be careful with that.

Some models automatically engage "park" and/or the parking brake when OFF.

If you have a brake controller for towing, OFF might not keep the brake vacuum up.

[OldBlackWater]

Well, this is embarrassing. When I did a quick subtraction of odometer readings after noticing there was even a difference, I got 12 miles, but after looking at my iPhone photos (I took pictures of the dash display since I didn't have a pen handy), I see that it's actually 312 miles, which is about how far I drove that day. So it must have been in "Ready to Drive" mode the entire time and didn't get enough airflow to keep cool. Fortunately, no damage was done.

I might just leave it off altogether (i.e. not in Acc mode) to help avoid this in the future. The manuals for the 2014 and 2015 C-Max both indicate this in the Recreational Towing section, so it's probably the same for the 2013, whose manual hasn't been revised in the last year.

By the way, I did install a charge line. It works great, with and without the engine running!

[wilanddij]

Do you have a charge line from the MH to keep the 12V battery from discharging while underway? Usually, the first noticeable thing that happens if the 12V batt discharges when towing is that you have to jump start it (at least that happened on my non-Energi C-Max), but I guess other symptoms might not be out of the question. Still, might be a good idea to install a charge line if you don't have one.

[OldBlackWater]

Dropped my C-Max off at the Ford dealer this morning and explained what happened. The service advisor called later to say that the engineer he talked to explained that the only way the fan motor would come on is if the car was on -- no way it would come on in Acc mode. It's certainly possible that I could have left it on, forgetting to power off then back into Acc mode. I forgot to mention to him that only 12 miles were added to the odometer, so there's still a bit of a mystery there.

I do have the remote start feature. The key fob was in the lower pocket of my cargo shorts, and it's not easy to double-click the button to activate it, but I can't rule that possibility out 100%.

I'll update again if I learn anything new. If anyone has any other theories or their own experiences, please share.

[willald]

OldBlackWater wrote:
...I slightly exceeded the 70 mph limit once when trying to finish passing a truck and cresting a hill. I got up to 71, 72 tops.

That happens with me from time to time, too. The speed can sneak up on you on the highways, especially when you're trying to pass a slower vehicle and get back over out of the left lane quickly. I don't think there is any harm from that at all, so long as you don't get too far over for too long.

I can't say for sure that it was in neutral the entire time, but I'm sure it was in N when I discovered the problem and got in the car to press the brake pedal and make sure it started. I had traveled 300 miles that day but only 12 miles were logged. Maybe some bumpy stretches of the highway bounced it into gear and then bounced it back into neutral.

I wasn't suggesting, that you accidentally left it in drive or a gear other than neutral (or that it would have shifted out of neutral on a bumpy road). If that was the case, I think you would have had much more immediate and catastrophic transmission damage.

What I am wondering, is if maybe you did not get the engine/drivetrain turned off as it should be, and it was still active? Just a completely wild guess on my part, but if that did happen, it could explain what happened here.

Another completely wild guess: Does your vehicle have the remote start capability on the FOB? Could somebody have accidentally pressed it at some point in the trip, causing the C-Max drivetrain to turn on?

I'm taking it to the dealer this week for regular service anyway, so I'll ask them to check everything out.

Great idea, I would, too. Do post back on here and let us know what Ford tells you. I'm curious to see what may have caused this.

Will

[OldBlackWater]

Thank you all for the replies. I appreciate everyone's thoughts and assistance in diagnosing the problem.

Dan/Nickie, thanks for posting the towing procedure. I mostly followed that, with three exceptions that I would consider minor:

1. The engine didn't stay idling for a full minute at the beginning of the day. I've been lazy with this and should probably do more to keep the engine from shutting off early, like turning on the defrost and holding the accelerator down. I'll follow this more closely in the future.

2. I put it into Acc mode instead of Off, although it shuts itself off shortly after Iock the doors anyway (2013 manual says to put it into Acc mode).

3. I slightly exceeded the 70 mph limit once when trying to finish passing a truck and cresting a hill. I got up to 71, 72 tops.

Will/Angela, I especially appreciate your thoughts as a FFH owner. I can't say for sure that it was in neutral the entire time, but I'm sure it was in N when I discovered the problem and got in the car to press the brake pedal and make sure it started. I had traveled 300 miles that day but only 12 miles were logged. Maybe some bumpy stretches of the highway bounced it into gear and then bounced it back into neutral. The EV battery state of charge indicator showed 2 miles remaining both before and after towing that day.

I'm taking it to the dealer this week for regular service anyway, so I'll ask them to check everything out.

[willald]

Agree with previous poster, something is definitely amiss here. I own a Ford hybrid (Fusion) as well, and know a little 'bout them.

With a Ford hybrid vehicle being flat towed, there is no way the gas engine (or electric motor for that matter) should EVER be able to come on, let alone come on and run enough to get the gas engine that hot! My guess is one of the following:

1. Something is seriously, seriously wrong with your C-max, and needs to go to the dealer ASAP to find out what.

2. Some how, some way, a blunder was made when hitching up, and the engine/drivetrain was accidentally left ON when towing.

If #2 is what happened, this could kind of make sense, why mileage was logged for the last 12 miles and overheated. With Ford Hybrids, generally the gas engine only turns on when either:

A) demand for power exceeds power electric motor and battery can provide, or
B) the batteries deplete low enough that gas engine engages to re-charge batteries.

If you accidentally left the engine/drivetrain ON when you hitched up, its possible the gas engine would not come on until the last 12 miles - That might have been the point where the batteries were depleted enough that it forced the engine to come on.

As to how/why the engine over-heated when it turned on for last 12 miles: Not sure on that, but given that Ford does NOT intend for that engine ever to come on when flat towing, nor do they intend for regenerative braking or most other electronic systems to be on when towing (and they may have been)....I can see how overheating might could occur under the conditions described.

Either way, whether you think you may have accidentally left drivetrain on when towing or not, I think I'd still take it to a dealer to be checked out.

[klutchdust]

while we enjoyed the deliciousness of oversized burger patties on buttery toasted buns.

Has this ever happened to anyone else?

This part has.

[Vulcan_Rider]

There are special considerations for towing a hybrid with 4 wheels down.
Some models even recommend against doing it at all.

If you have a hybrid, get the recommended procedure specific to your model.

THE MILEAGE SHOULD NOT ACCUMULATE AND THE COOLANT TEMP. SHOULD NOT COME ANYWHERE NEAR THE 230 F OR SO IT TAKES TO OVERFLOW. Something is definitely amiss.....and it could turn out to be expensive in the end.

[dan-nickie]

I assume you have read and follow these guidelines:

Recreational Towing
Note: Put your climate control system in
recirculated air mode to prevent exhaust
fumes from entering the vehicle. See
Climate Control (page 107).
Follow these guidelines if you have a need
for recreational (RV) towing. An example
of recreational towing would be towing
your vehicle behind a motorhome. We
designed these guidelines to prevent
damage to your transmission.
You can tow your vehicle with all four
wheels on the ground or with the front
wheels off the ground by using a tow dolly.
If you are using a tow dolly follow the
instructions specified by the equipment
provider.
If you tow your vehicle with all four wheels
on the ground:
• Tow only in the forward direction.
• Release the parking brake.
Vehicles with Push Button Start
1. Start the vehicle by pressing the brake
pedal, and then pressing the ENGINE
START/STOP button until the vehicle
starts.
2. Press the brake pedal and shift the
transmission into position N.
3. Turn the vehicle off by pressing the
ENGINE START/STOP button once.
(Trip Summary appears in the left
instrument cluster screen when the
vehicle is off.)
Note: You can remove the key fob from the
vehicle while towing

Vehicles with Ignition Key
1. Start the vehicle by pressing the brake
pedal, and then turning the ignition key
until the vehicle starts.
2. Press the brake pedal and shift the
transmission into position N.
3. Turn the vehicle off by turning the
ignition key past the accessory position.
The key position is between the
accessory and off positions. See
Ignition Switch (page 127). (Trip
Summary appears in the left
instrument cluster screen when the
vehicle is off.)
Note: If your vehicle is equipped with an
ignition key, you cannot remove the key from
the ignition cylinder when the transmission
is in position N and the vehicle is off.
All Vehicles
• Do not exceed 70 mph (113 km/h).
• Place the transmission in position P,
start the vehicle, and allow the engine
to run for one minute at the beginning
of each day (you may need to press the
accelerator pedal in order to start the
engine). After allowing the vehicle to
run, place the transmission back into
position N and the ignition in the off
position.
Note: A SHIFT TO PARK or
TRANSMISSION NOT IN PARK message
may appear in the information display when
the transmission is in position N and the
ignition is in the off position.

[HMBdave]

I dont know anything about towing a vehicle beind an rv, but i belive i C-max is a hybrid. My understanding of a hybrid is that if you are not acelerating the wheels are generating energy to charge the batties? I would assume the car is in neutral with the key in the acc. Position or is there a way to put it in neutral and still get the key into off position?

[pigman1]

How does the radiator look? Could you have picked up some substance (mud, tar, cottonwood duff, etc) that caused the overheat?