2020 F350 6.7 weak start

[way2roll]

I bought my 2020 F350 6.7 new and I've put about 28k on it. I haven't had a single issue with this truck until now. Sometimes the truck sits for a day or so without being used and when that happens it's a "weak" start. It always starts (knock on wood) but the last thing I want is to be on a trip pulling the FW and it doesn't start. There is no code. It has 2 batts and frankly I don't know how to test voltage on a 2 battery setup and voltage isn't always the best indicator anyway. And I do know, if one batt is bad it drags down the other. I've also read that these trucks have had issues with the starters. It's still under warranty and I was told to make an appointment for a diagnostic test. But I trust you guys more than I trust a dealership and thought I'd throw it out there to get your thoughts so they don't brush me off. Also been noticing intermittent hard shifts into 3rd on a slight grade. Again no code, but I have heard there have been issues with these tranny's and intermittent hard shifting. I plan on asking them about it, but again, always worry about an honest opinion from the dealership. They always seem to find stuff when the warranty is over, but funny how they can't find the issues when it's covered.

[ford_truck_guy]

way2roll wrote:
Got it back from the dealer and when I started the next morning the start was weaker than it's ever been. It's probably close to not starting at all. Also it's starting to do weird electronic things, like the window going down when I press it to go up and the clock keeps resetting itself to 24 HR. I change it back and the next day it resets. Based on what I've read these are clear signs the batteries are going bad. Having them load tested today at the auto parts store. It's also clear the dealership essentially did nothing. If it's the batteries, can I get them replaced under warranty without the dealership? Do I just bite the bullet and buy better batteries than the motorcraft ones? I'll have to look but I think the batts carry their own warranty but being motorcraft I assume it's through Ford.

IF it were me.. IF the bats came back as BAD after the load test, I would take that truck right over to Ford and have them load test it in front of you.. The issue will be that they will say that bats may not be covered as people can cause harm to them by leaving STUFF on at night.....BUT, It won't hurt to ask / demand....

[way2roll]

Got it back from the dealer and when I started the next morning the start was weaker than it's ever been. It's probably close to not starting at all. Also it's starting to do weird electronic things, like the window going down when I press it to go up and the clock keeps resetting itself to 24 HR. I change it back and the next day it resets. Based on what I've read these are clear signs the batteries are going bad. Having them load tested today at the auto parts store. It's also clear the dealership essentially did nothing. If it's the batteries, can I get them replaced under warranty without the dealership? Do I just bite the bullet and buy better batteries than the motorcraft ones? I'll have to look but I think the batts carry their own warranty but being motorcraft I assume it's through Ford.

[Grit_dog]

way2roll wrote:
It's no coincidence they never seem to find much wrong with your vehicle under warranty, and then miraculously find a host of things that need addressed once the warranty expires.

Ding ding ding! We have a winner!
That trans issue I wrote about, The same issue I took it in for at very low miles caused the failure 60k miles later. That issue caused another issue/symptom. Both of which I told the dealer when took it for repairs. They attempted repair ineptly twice. Once replacing the first part second replacing the part that got messed up by the first problem. And thanks to trying to scrimp on warranty work, they did 2 major repairs. 1 w trans removed and one in-frame. And then ended up replacing the whole trans.
To think 2 years and 60k miles earlier, they could have fixed it for the cost of the first repair only. But ended up with 4x the work and 5x the cost.

[way2roll]

It's no coincidence they never seem to find much wrong with your vehicle under warranty, and then miraculously find a host of things that need addressed once the warranty expires.

[Grit_dog]

^ Yeesh!
Good luck man!
Would seem both issues would be covered or potentially covered (idk if actual batteries are, but you have evidence or at least recollection of a light staying on) by the bumper to bumper warranty.
If they "can't replicate" the issue either you're lying ( you not, why would you subject yourself to going to the dealer for repairs if there wasn't an issue? lol) or they "didn't notice" it.
If they try to charge you, maybe suggest a test drive WITH the tech so you can point it out.
Been there, done that.
Had warranty work on a trans a few years ago on my company truck. The service guy actually told me, hey it's going to shift hard for a bit on you until the transmission re-learns.
I leave, and same symptoms are present as before I brought it in.
Dude actually was pre-emptively trying to pass of a bad repair job as trans re-learning....
another month later it came back with a new transmisison. 2 attempts to repair the original one and a third try by replacing the whol etrans.

[way2roll]

So the dealership called again and same thing. No issues can be found or replicated. I know my truck and I know it's starting weaker. I may take it to the auto parts store to have them test the batts as they are an independent party. The good news is that the dealer diagnostic didn't cost me anything.

[way2roll]

Update - sort of.

Dealership has had the truck since Saturday. The thinking that the longer it sat until Monday would provide evidence of a weak start. Anyway, they called and said it started just fine. I asked if they load tested the batteries - no. They also said the transmission issue of a hard shift into 3rd could not be replicated. So they said they would keep it an extra day to load test the batts and investigate the trans issue further. They also said they have had no examples of issues with the transmissions. A little contradictory to what I am reading on line.

Curious what this "diagnostic test" will cost me.

More to come today. Or not. LOL

[mkirsch]

Carbon pile battery testers are not expensive and tell you more than a voltmeter. The cheaper ones may not put a good enough load on the battery for some people but I personally have never had a "false positive" where a weak battery shows good. In fact it's usually the other way, the battery tests marginal or weak but still does its job.

[dieseltruckdriv]

theoldwizard1 wrote:
Typical new user no follow up.

He just posted this morning, 2 hours before you posted this.

[Grit_dog]

theoldwizard1 wrote:
Typical new user no follow up.

Typical inane response....since the OP has been here for over 3 years and followed up this morning....lol

[way2roll]

Update - so there is an additional problem, or a result of the problem.

I went out to start it today as it's been a couple days. Weak start but it started. I noticed after a short drive that the rear dome light was staying on. No matter what I tried, switches on the light itself, dimmer, opening and closing all doors, it won't shut off. Now I don't know if this is draining my battery or my battery draining is causing some malfunction, but it is interesting to note. I do drive at night and this is the first I've noticed it. The battery has been getting weaker for 2 weeks or so. So it's either intermittent or a result of another issue. I wonder if it's an control module issue.

Curious if they find it's a faulty light or a control module issue and it killed my batts if they will warranty new batts. I'll find out Monday.

[way2roll]

theoldwizard1 wrote:
Typical new user no follow up.

Huh?

:h

[theoldwizard1]

Typical new user no follow up.

[theoldwizard1]

jdc1 wrote:
More and more **** is added to vehicles that have a memory, drawing power while you sleep.

While the vehicles HAVE had more and more electronics added, they should ALL go to "sleep" within 1-2 minutes. Current draw should be around 10 mA with an occasional short bump to maybe a couple hundred mA.

If NOT, the module is bad.

[phillyg]

It's not the first time I've heard of this problem. I suggest you go the warranty route for a good diagnostic. My 350 is much older and its not a daily driver, but if I leave it for more than a week I can tell the batts have been subject to a parasitic draw.