2016 3.5L Ecoboost doesn't start randomly
10-25-2020, 01:02 PM
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2016 3.5L Ecoboost doesn't start randomly
I have searched everywhere for the answer to this and cannot figure it out. Sorry in advance for the long post, I think the details are pertinent to show the inconsistencies with the truck not starting. Please read and help me figure this out! I am also not very mechanically inclined, only basic stuff.
I have a 2016 3.5L Ecoboost that intermittently won't start up. It seems to be every time we go camping and it is never dead at home. This started about 2 months ago and I thought it was the battery. When we go camping, the truck would be dead in the morning when we go to start it. After the first time this happened, we are very careful to not leave the doors open and I make sure I start the truck before bed and right when we wake up, if it will start. I thought it somehow correlated to the doors being open too long, but we would maybe have them open for 10 minutes total, which doesn't make any sense why it would be dead after that amount of time.
The truck won't turn over, it just clicks multiple times. Possibly the starter?
I got the battery tested, which actually turned out to be okay, but I figured I would upgrade anyways. I bought a yellow top Optima from autozone and thought, great, this will never die on me. I accidentally tested it out right after purchasing it by leaving my doors open without realizing it. They were probably open for about 2 hours and I thought the truck would never start, but it did! Problem solved, I thought.
Recently on a trip to Moab, we camped overnight, woke up the next morning and the truck started up! Of note, it was very slow to crank and turn over. I shut it down, we had breakfast, barely opened the doors to load gear, and the truck was then dead! It did the same clicking and wouldn't start. After getting a jump we were up and running and the truck never dies anymore during the course of the day. We continued on to our families house in Colorado and the next morning, the truck was dead again! It was cold that night, maybe 32 F, so I thought the cold may have something to do with it, as this was the first time it was dead while not camping.
I decided to put a multimeter on when it was dead and I got a reading of 10.5 volts. I jumped the truck, did another reading while it was running, and got 14.5 volts. I shut down the truck, left he multimeter on, and left the doors open.... After 10 minutes, the battery drained back down to 10.5 volts. So it seems like the alternator is working, but there is some sort of parasitic drain over night and possibly with the doors open. I jumped it again and never had another issue.
We then went back to Moab, continued camping, and every morning, the truck was dead and we had to jump it. When jumping, it starts right up immediately and runs for the rest of the day without an issue. We went biking for 6+ hours, came back to the truck that evening and it starts right up. No issues at all during the day.
The last day of camping, we got the truck jumped and headed back home to Idaho. I mention these places because I also weirdly thought elevation could be a factor? But it seems to only do this while we are camping and that one random time in Colorado.
So we get back home, it's starting to get cold out, lows have been about 30 F at night and I thought this would be a great test. I wake up in the morning at home the next day, go to start the truck and it starts perfectly fine. Every day since we got back home, it has started up like it normally would, no hesitation, never dead. When I go to work, it sits for 12+ hours and starts up every time with no hesitation.
I have no accessories installed, everything is factory. I don't leave doors open, I don't leave lights on, I have even started unplugging all cords at night when we are camping, but it still dies. The alternator seems to be charging the truck and I figure the battery is good because the truck starts every single day at home. I feel like if it was the starter, it would be more consistently dead. I have checked the cables, there is no corrosion and from what I can see the cables are tight. At home, I can leave the doors open for a long time and the truck will never die. I can't figure out the common denominator for when it won't start, except for the fact that it does it every morning while camping. So what I'm thinking now is that when we are camping, we are always in a small trailer or tent directly next to the truck. Could it be the SYNC system or bluetooth trying to connect because of the close proximity? I want to try and figure this out before spending a ton of money on diagnostics at the shop. It is very hard to replicate this issue for someone else to experience.
If anyone has had this issue or knows of this, please help!!
I have a 2016 3.5L Ecoboost that intermittently won't start up. It seems to be every time we go camping and it is never dead at home. This started about 2 months ago and I thought it was the battery. When we go camping, the truck would be dead in the morning when we go to start it. After the first time this happened, we are very careful to not leave the doors open and I make sure I start the truck before bed and right when we wake up, if it will start. I thought it somehow correlated to the doors being open too long, but we would maybe have them open for 10 minutes total, which doesn't make any sense why it would be dead after that amount of time.
The truck won't turn over, it just clicks multiple times. Possibly the starter?
I got the battery tested, which actually turned out to be okay, but I figured I would upgrade anyways. I bought a yellow top Optima from autozone and thought, great, this will never die on me. I accidentally tested it out right after purchasing it by leaving my doors open without realizing it. They were probably open for about 2 hours and I thought the truck would never start, but it did! Problem solved, I thought.
Recently on a trip to Moab, we camped overnight, woke up the next morning and the truck started up! Of note, it was very slow to crank and turn over. I shut it down, we had breakfast, barely opened the doors to load gear, and the truck was then dead! It did the same clicking and wouldn't start. After getting a jump we were up and running and the truck never dies anymore during the course of the day. We continued on to our families house in Colorado and the next morning, the truck was dead again! It was cold that night, maybe 32 F, so I thought the cold may have something to do with it, as this was the first time it was dead while not camping.
I decided to put a multimeter on when it was dead and I got a reading of 10.5 volts. I jumped the truck, did another reading while it was running, and got 14.5 volts. I shut down the truck, left he multimeter on, and left the doors open.... After 10 minutes, the battery drained back down to 10.5 volts. So it seems like the alternator is working, but there is some sort of parasitic drain over night and possibly with the doors open. I jumped it again and never had another issue.
We then went back to Moab, continued camping, and every morning, the truck was dead and we had to jump it. When jumping, it starts right up immediately and runs for the rest of the day without an issue. We went biking for 6+ hours, came back to the truck that evening and it starts right up. No issues at all during the day.
The last day of camping, we got the truck jumped and headed back home to Idaho. I mention these places because I also weirdly thought elevation could be a factor? But it seems to only do this while we are camping and that one random time in Colorado.
So we get back home, it's starting to get cold out, lows have been about 30 F at night and I thought this would be a great test. I wake up in the morning at home the next day, go to start the truck and it starts perfectly fine. Every day since we got back home, it has started up like it normally would, no hesitation, never dead. When I go to work, it sits for 12+ hours and starts up every time with no hesitation.
I have no accessories installed, everything is factory. I don't leave doors open, I don't leave lights on, I have even started unplugging all cords at night when we are camping, but it still dies. The alternator seems to be charging the truck and I figure the battery is good because the truck starts every single day at home. I feel like if it was the starter, it would be more consistently dead. I have checked the cables, there is no corrosion and from what I can see the cables are tight. At home, I can leave the doors open for a long time and the truck will never die. I can't figure out the common denominator for when it won't start, except for the fact that it does it every morning while camping. So what I'm thinking now is that when we are camping, we are always in a small trailer or tent directly next to the truck. Could it be the SYNC system or bluetooth trying to connect because of the close proximity? I want to try and figure this out before spending a ton of money on diagnostics at the shop. It is very hard to replicate this issue for someone else to experience.
If anyone has had this issue or knows of this, please help!!
10-25-2020, 01:43 PM
#2
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I hate to say this, but I recommend ditching the Optima. Since they were bought out by Johnson Controls and manufacturing moved to Mexico, their batteries are not what they used to be.
That being said, the battery is not likely the root cause of your issue. Do you have Push Button start? When camping, do you leave the fob in the truck? Leaving the fob in or near the truck will prevent several of the modules in the truck from going into sleep mode. This results in increased drain of the battery. You may also have a failing module or a minor wire short that is pulling power when the truck is turned off. You need to test the resting current draw, which should be less than 50 mA. There is a specific test procedure for this.
Assuming your Yellow Top is an H6, the C20 rating is 72 Ah. C20 Rating is the energy a battery can deliver continuously for 20 hours at 80°F without falling below 10.5 volts. This means your battery should be able to deliver 3.6 A for 20 h. That is way more than the 50 mA your truck should be drawing when shut off and powered down.
That being said, the battery is not likely the root cause of your issue. Do you have Push Button start? When camping, do you leave the fob in the truck? Leaving the fob in or near the truck will prevent several of the modules in the truck from going into sleep mode. This results in increased drain of the battery. You may also have a failing module or a minor wire short that is pulling power when the truck is turned off. You need to test the resting current draw, which should be less than 50 mA. There is a specific test procedure for this.
Assuming your Yellow Top is an H6, the C20 rating is 72 Ah. C20 Rating is the energy a battery can deliver continuously for 20 hours at 80°F without falling below 10.5 volts. This means your battery should be able to deliver 3.6 A for 20 h. That is way more than the 50 mA your truck should be drawing when shut off and powered down.
10-25-2020, 01:52 PM
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I hate to say this, but I recommend ditching the Optima. Since they were bought out by Johnson Controls and manufacturing moved to Mexico, their batteries are not what they used to be.
That being said, the battery is not likely the root cause of your issue. Do you have Push Button start? When camping, do you leave the fob in the truck? Leaving the fob in or near the truck will prevent several of the modules in the truck from going into sleep mode. This results in increased drain of the battery. You may also have a failing module or a minor wire short that is pulling power when the truck is turned off. You need to test the resting current draw, which should be less than 50 mA. There is a specific test procedure for this.
Assuming your Yellow Top is an H6, the C20 rating is 72 Ah. C20 Rating is the energy a battery can deliver continuously for 20 hours at 80°F without falling below 10.5 volts. This means your battery should be able to deliver 3.6 A for 20 h. That is way more than the 50 mA your truck should be drawing when shut off and powered down.
That being said, the battery is not likely the root cause of your issue. Do you have Push Button start? When camping, do you leave the fob in the truck? Leaving the fob in or near the truck will prevent several of the modules in the truck from going into sleep mode. This results in increased drain of the battery. You may also have a failing module or a minor wire short that is pulling power when the truck is turned off. You need to test the resting current draw, which should be less than 50 mA. There is a specific test procedure for this.
Assuming your Yellow Top is an H6, the C20 rating is 72 Ah. C20 Rating is the energy a battery can deliver continuously for 20 hours at 80°F without falling below 10.5 volts. This means your battery should be able to deliver 3.6 A for 20 h. That is way more than the 50 mA your truck should be drawing when shut off and powered down.
What would you recommend instead of the Optima? I'm not sure I can just ditch it at this point if it is, in fact, working. Too much money!
10-25-2020, 02:00 PM
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10-25-2020, 02:08 PM
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Here is the test procedure.
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Blackbuzzard (10-25-2020)
10-25-2020, 10:35 PM
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my coworker had this happen last week. he replaced the battery, thinking that was it, old battery tested fine. then the starter, which was also fine. then took it to the dealer and found out it is something to do with the factory security system. some module and its antenna shorted out and it would click but would not send signal to starter. cost him 1700 out of warranty for the module, antenna, install and programming. plus he bought the battery and starter.
10-25-2020, 11:15 PM
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my coworker had this happen last week. he replaced the battery, thinking that was it, old battery tested fine. then the starter, which was also fine. then took it to the dealer and found out it is something to do with the factory security system. some module and its antenna shorted out and it would click but would not send signal to starter. cost him 1700 out of warranty for the module, antenna, install and programming. plus he bought the battery and starter.
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10-26-2020, 08:36 AM
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Phrasing is everything...
I read the title - 2016 3.5L Ecoboost doesn’t start randomly - and my immediate thought was “Well, I sure hope it doesn’t start randomly; it should only start when you want it to!”
I read the title - 2016 3.5L Ecoboost doesn’t start randomly - and my immediate thought was “Well, I sure hope it doesn’t start randomly; it should only start when you want it to!”
Last edited by SHOOT1SAM; 10-26-2020 at 10:48 AM.
10-26-2020, 08:51 AM
#9
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If this only happens after pulling a trailer, then make sure your wiring on the connectors on the rear of the truck is not having issues. Maybe after plugging the trailer connector it thinks the trailer is still plugged in causing the battery to drain. If it does not happen during normal use.
10-26-2020, 09:52 AM
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Oh wow, that cost isn't encouraging. Do you know if his was random like mine or pretty consistent all the time? I wish I could fix it myself, but if mine is doing the same thing, the dealer may be the only option. I'm going to test with the multimeter this week to see if I can find something pulling amps.
his was random. The reason he bought the battery is because a few times we jumped it with cables and it started. But he told me there were times he tried that at home to leave and it didn’t work. That’s why he did the starter next. After that it was still doing it random is when he took it to the dealer and found out the bad news.