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.

[way2roll]

schlep1967 wrote:
There is a new battery purchase in your near future. Probably one of the batteries is bad but you can't just replace one.

Agreed. One thing I do know is that all batteries should be replaced at the same time. I'll let you guys know what Ford says.

On Edit, got an appt for Monday. They want me to drop it off Sat so it sits for a few days to try and replicate the problem. She seemed familiar with the issue as well as with the hard shifting into 3rd. Hopefully they are both easy fixes. Didn't think to ask if I am paying for this diagnostic test. Been over a decade since I've had a new vehicle.

[schlep1967]

There is a new battery purchase in your near future. Probably one of the batteries is bad but you can't just replace one.

[way2roll]

Grit dog wrote:
So it cranks slower after sitting for only a day, but cranks faster if started within the same day as it was run last?
If that's the case, it is not the starter, it is the batteries.
If you dont want to test them, and suspect bad battery/power draw, just let it sit for a few days and see if it's worse than 1 day. Otherwise, check battery voltage of each battery separately and/or have them load tested.

That's where I'd start (no pun intended, lol)

Ha!, I love a good pun.

This pretty much explains the problem. It's a weak start after sitting a few days, but started on the same day or after being driven it starts right up. I guess that does sound like a battery problem. Just interesting that the batts would go bad in 2 years?

[Busdriver]

Power strokes are hard on battery life

[way2roll]

Appreciate all the replies. I'll make the appointment at the dealership and let you know what they find out.

[blofgren]

It could very well be the batteries getting weak, although Motorcraft batteries are known to be very good.

My Ram was beginning to crank slower at around year 3 as well, and I was having all sorts of weird glitches with the stereo and instrument panel. Then one day it wouldn't start. I installed 2 new fresh Kirkland batteries and all has been fine since. Erratic voltage from batteries starting to go south wreaks havoc on newer vehicles.

Please keep us posted!

[Retired_JSO]

Cold weather start on 6.7 will take a second or two before the starter engages to allow the glow plugs to cycle.

[jdc1]

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

[dieseltruckdriv]

Fisherman wrote:

thomasmnile wrote:


We have a 2019 Highlander. Was sitting in a parking lot waiting on my wife while she was in a fabric store. Ignition in accessory position, radio on nothing else. The master alarm suddenly goes off and the dash display pops the following message " shutting Ignition off to conserve battery". Radio only????? After 20 minutes????
.....

Mfgr's put the smallest battery in there, thank the bean counters.

Actually not always. My wifes Taurus takes the same battery as my 7.3l Powerstroke. Only one of them though. 😉

My best friend has a 2017 or 18 6.7l and he left his sit most of the winter without starting it and it cranked right up when he tried it early this spring.

[RAS43]

Couple of issues and under warranty, time to trust the dealership, IMO.

[Fisherman]

thomasmnile wrote:


We have a 2019 Highlander. Was sitting in a parking lot waiting on my wife while she was in a fabric store. Ignition in accessory position, radio on nothing else. The master alarm suddenly goes off and the dash display pops the following message " shutting Ignition off to conserve battery". Radio only????? After 20 minutes????
.....

Mfgr's put the smallest battery in there, thank the bean counters.

[thomasmnile]

Have both batteries load tested?

Parasitic draw? What vehicle built these days doesn't have them? So many computers and stuff in vehicles now....

We have a 2019 Highlander. Was sitting in a parking lot waiting on my wife while she was in a fabric store. Ignition in accessory position, radio on nothing else. The master alarm suddenly goes off and the dash display pops the following message " shutting Ignition off to conserve battery". Radio only????? After 20 minutes????

Good thing I can stream Sirius XM on my phone. Geeez.......

[Bob_Olallawa]

way2roll wrote:
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.

I think you should make the appointment to get it checked out. Maybe they will find the problem and take care of it.

[theoldwizard1]

So you have an intermittent "crank, no start".

• Check the battery voltage at both batteries. It should be identical.
• Does it crank a "full speed" or is it cranking slower ?
• The time that it did not start, what did you do to make it start ?

[way2roll]

My local auto parts store is literally a mile up the street. I'm certain they are better at doing a batt test than me. Does it make sense for them to check the batts before making an appt at the dealer and possibly leaving it there?