Heater Coolant Hot when Charging - Teakettle Syndrome

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garygid

Well-known member
Joined
Apr 21, 2010
Messages
12,469
Location
Laguna Hills, Orange Co, CA
"starry" drove home from dealer and with 5 bars showing, connected the Nissan L1 EVSE to begin charging about 7:30 PM. He got about a 15-hour estimate on Carwings. Since he was parked in his driveway, he put a cover over the precious new LEAF to keep the exhaust from passing seagulls from soiling the paint.

At about 7 this morning, Carwings says 2 bars remain and 5 hours remain. Slightly strange that it did not make more progress in the 12.5 hours it was charging, but it might have been almost up to the top bar. The SOC granularity makes it impossible to tell. He sees the "third" light blinking (normal), but hears strong bubbling, like a teakettle (not normal). The battery temp seems normal when looking at the left-hand dash gauge in 2nd ACC mode. Opening the hood, the coolant overflow seems full, the coolant is quite hot, and he can see the two fans, but neither fan is turning (would seem wrong).

It seems to him that the coolant might be (is probably) circulating. I had him stop the charging to let the car cool, since even driving it to a dealer might be unwise with it so hot. Too bad, he had an 80-mile trip planned for today.

Calling dealer's Service departments from 7:30 to 8:00 AM:

1. The delivery dealer (about 20 miles away) ... Sorry, our LEAF-trained tech. only works "banker's hours" (not there until later).

2. calling the closest dealer (about 9 miles away) ...

3. calling Connell Nissan (about 40 miles away) for more experienced engineers ...

I will get him to look for coolant overflow on the ground.

Note: While the car was L2 charging at the dealer, I did not notice any cooling fan noise.
 
There must be a pump that circulates the coolant through the charger as well as a fan, not to mention relays and control stuff. Sounds like something in all that is broke.
 
sometimes i kinda hear a "fan-like" sound but not usually. this is on 120. i have never heard bubbling, but to be honest with ya, after 3+ months, i dont fawn over it like a newborn any more. it simply does not seem to have issues.

this is definitely an issue i would investigate.
 
I agree, the pump(s) or the fan(s) in the cooling system are likely, or the heat sensor or the colling system controls.

He agreed that he should not try to drive the LEAF in this "overheated" condition.

He will take his trip in his old car, and let the LEAF cool, trying to get it in for service this afternoon after he gets back.
 
Assuming the charger is 90% then charging at 3300W produces 370W of waste heat.. probably enough to heat up the coolant to the bubbling stage overnight, if the fan is not running.

An external DC charger would keep all this heat outside the car, the disadvantage is that you would have to take the charger with you if you wanted to plug-in at work.
 
One LEAF-Trained tech says (rough translation):

Is the battery temp OK? (Yes)
The cooling system cools the battery.
It is normal to have bubbling during charging.
So, just continue driving it.

However, another dealer's Service guy says:

Don't drive it to us, have it transported in to us.
Yes, it sounds like something is wrong.

---
So, has ANYBODY had extended bubbling sounds and coolant flow into the overflow bottle (front, left of center), especially during extended-duration charging?
 
garygid said:
So, has ANYBODY had extended bubbling sounds and coolant flow into the overflow bottle (front, left of center), especially during extended-duration charging?
I've never done extended Level 1 charging (5 hours at the most right now), but I've heard the pumps whirling the coolant around (which I guess could sound like "gurgling") and it does get warm, but I wouldn't call it hot. As the coolant gets warmer and cooler it should be normal for fluid to flow to/from the expansion bottle, but as warm as I've noticed it I wouldn't think it would change very much.
 
garygid said:
So, has ANYBODY had extended bubbling sounds and coolant flow into the overflow bottle (front, left of center), especially during extended-duration charging?
On what I believe was my first charging sessions I was surprised at all the noise the car made. I popped the hood, and noticed that there was bubbling going on with the coolant unit in the back left (just left of the DC inverter). I have not paid much attention since, so I don't know if this is happening every time or not.
 
Drove 79 miles yesterday. Plugged in at 7:30 pm last night. Checked it at 10:20 and 5:25 am this morning. Not a sound but very very faint fan sound.

Sounds like that is the missing element.
 
Got a flatbed to Connell Nissan where there are kind, helpful folks with considerable LEAF expertise available.

Conjecture is that the cooling system was not "purged" properly at delivery, and that it has air in some of the "voids" back near the charger. These air pockets might overheat, cause steam, etc.

They are going to check for error codes, purge the cooling system properly, and run some tests.

My questions:

1. Were the fans operating properly?
(Presumably they should have been ON full speed at the very-hot temperature.)

2. Why did the charger keep charging at the elevated temperature?
(Did it record any "too-hot" codes?)
 
garygid said:
1. Were the fans operating properly?
(Presumably they should have been ON full speed at the very-hot temperature.)

2. Why did the charger keep charging at the elevated temperature?
(Did it record any "too-hot" codes?)
If it was localized boiling caused by bubbles in the cooling system, the car probably would not have detected any overheat condition thus never turning on the fans or stopping charging.

The Connell Nissan techs seem to be spot on.
 
garygid said:
My questions:

1. Were the fans operating properly?
(Presumably they should have been ON full speed at the very-hot temperature.)

2. Why did the charger keep charging at the elevated temperature?
(Did it record any "too-hot" codes?)

Good questions Gary. It sounds like maybe not all error or failure routes are known or fully understood. The real answers to these questions, if fully investigated by Nissan, might end up in firmware rev E - which would henceforth be known as the garygid firmware.
 
Got the car back.
They properly got the air out of the HV coolant system (inverter, charger, and motor).
No codes found.
They charged (L2) for about an hour (or so) and things seemed normal: "unable to reproduce the problem".

So, hopefully that was it, just that the coolant system was not properly serviced before delivery and there were air pockets in the charger.

But, that still does not quite match all the symptoms.

So, we will watch and report anything further.
 
Drove car home Friday eve after techs said "could not reproduce problem" with boiling fluids in tanks. Charged Level 1 for three hours, some boiling in both small white tanks under hood, and level of overflow tank in front went up to MAX. Turned off charger and went to bed, checked at 0630 Sat. Car all cool, coolant overflow tank down to MIN. Plugged in Level 1 charger for five hours or so. Came out, every tank and tube for fluid under hood was very hot, bubbling, and overflow tank was full up to the cap. Turned off charger, let car cool again.
At no time during these charging and boiling sessions was the A/C heater system ever on, or ever programmed to turn on at any time, either from car control panel or CARWINGS. At no time have I ever heard or seen or felt either fan in front of the motor be on. I do hear pump motor noise as a faint hum.
Called Service scheduler at dealer and he advised to have car trucked in again Monday, but his LEAF tech expert(s) (s?) would be absent until Wednsday.
I will drive car Sunday a bit, and drive to dealer (30 miles) on Monday. Purpose is to discharge battery down to point where it can be charged in dealer's presence at Level 1 for at least five hours. This is because that routine would duplicate what I do. None of this Level 2 charging for an hour or so and pronouncing "unable to reproduce" will satisfy my request for an adequate investigation of the problem, if any.
Possible next level of effort would be making a video recording of my situation.
 
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