Failure to start in extreme cold

[waldguy]

Temperature outside: -34C (-30F)

Car mileage: 98K kms (60K miles)

Battery: 2 year old AGM Optima (800 CCA - turns car over fine in cold)

Condition:  Car was sitting outside, but plugged in.  The operator went to turn the key and got interior & dash lights, etc.  Turned key to start and nothing fired.  Tried shifting the transmission to N, still nothing.  Wiggled the steering wheel.  Nothing.  Went out, opened the car door, got in and slammed the door shut.  Turned key to "start" and it fired right up.

In the garage at about -8C (18F) the car has started every time.  I'm not sure where to begin with this....

[ammcinnis]

Have you ever had the ignition relays replaced per TSB 07-89-15R ... no-start under very cold conditions? I think this is one of the few TSBs that Subaru would authorize (under warranty) at customer request, even if you hadn't yet encountered the problem.

The TSB was later reissued as a recall, WTG-67R, affecting a limited range of MY 2015 (and 2016?) Legacys and Outbacks. As a recall, WTG-67 should still be valid for affected vehicles, even those out of warranty. See attachments.

TSB_07-89-15R_Ignition_Relays.pdf

Recall_WTG-67_Ignition_Relays_160830.pdf

[waldguy]

Thanks for reminding me of this.  I have on record that the recall work was supposedly done by the dealer in April of 2018.

In this instance, the car would not have warmed up much on its way to the parking spot (300 yards), and then it sat for several hours before the attempted start.  It would be interesting to apply warming to the relay(s) in question to see if that would make the difference.

Correction -- the car was sitting just a few minutes before the failed start (new info from the wife).

Edited December 9, 2022 by waldguy
New information

[ammcinnis]

I keyed in on the cold temperature and your report the car started after "slamming" the driver's door shut. The vibration could be enough to free sticky relay contacts.  Relay failures are rare, but for most of us so are starts at temperatures below -20 F.

[waldguy]

1 hour ago, ammcinnis said:

I keyed in on the cold temperature and your report the car started after "slamming" the driver's door shut. The vibration could be enough to free sticky relay contacts.  Relay failures are rare, but for most of us so are starts at temperatures below -20 F.

Wondering as well, if there's a neutral safety switch that might be affected by vibration?

[Max Capacity]

The other day, a guy over on the Outback.org had the seem type issue using a plug in cord. I suggested he call SOA and start a file with them. I have never plugged any car in, and never have had an issue when the battery was good and cables clean and tight. I tend to replace the Walmart Maxx Everstart battery before the 6th Winter. My cars are started a number of times while the temp is -29F over the past 30 years or so.

 

Other question, do you drive the car for some distance so the battery charge fully before shutting the car off. When I'm skiing in VT for a week and only driving the car a mile to the hill each day, after the third morning of starting, I tend to take the car for a ride for 7 miles after skiing that day to charge the battery.  7 miles is what I was told back in the 1970's.

[waldguy]

Thanks for the ideas.  The 2015 model battery charges not with necessarily with long runs, but with periods of deceleration due to the "smart" ECM management for fuel economy, or during night loads. 

On the night in question, the battery was likely at about 12.25 volts, perhaps just marginal enough not to crack the relays if "stuck" or frozen.  In addition I now found out that the plugin source breaker was turned off -- so the engine did not have the heated oil advantage.  The 0W20 flows relatively well regardless.

Nevertheless, the key turn at first did not engage the starter at all.  When it finally did, the engine turned over well enough.  So in this case I think I can rule out a faulty heater block cord.

How am I addressing this?  For the battery, I read and confirmed that a full charge can be force during daylight if I put on load like parking lights.  I may also get the battery TSB done (trip to the city and $75).  I also gave the battery terminals a slight wiggle and extra tighten.

I also confirmed that the relays are indeed the new ones (eg. M09) as specified in the relay update.

[ammcinnis]

9 hours ago, waldguy said:

I may also get the battery TSB done ...

Highly recommended.

[waldguy]

TSB was done yesterday along with some others.  Tech at dealership didn't know why it happened either.  He just suggested keep turning the key off on off on off on lots of times.  He said it was typically more of a problem with the push button start.

Apparently with one of the updates, he said, the battery will not be charged at all if the voltage drops below 11.6V.  That hasn't been a problem.  Just the same, I picked up a cheap load tester for occasional use -- car, boat, truck, etc.

Edited January 20, 2023 by waldguy