Starting issue when engine is hot on my 2014 Silverado 6.2liter

[Mark1427]

Could use some help with ongoing issue. With my job I drive about an hour then park my truck for about 45 minutes then drive another hour and park it again for 45 minutes and so on. Each time I come out the truck starts fine, the problem is if I stop for a coffee along the way and try to start my truck after only a few minutes of being shut off the truck won't start. It turns over but not enough to start. If I sit there for 15 or 20 minutes it will start (without jumping it). The problem is worse if the outside temperature is hot. I have noticed that the volt meter fluctuates between 12.7ish and 14 which appears to be normal for this truck. My truck has 120,000 miles and the battery is about a year old and was dealership installed. This has been going on for about 3 months ( I only use the truck a couple times a week). I would appreciate any suggestions what might be causing this issue. I'm leaning towards the battery but checking to see of anybody else had this issue and found out it was something other than the battery. Thank in advance! 

[swathdiver]

1 hour ago, Mark1427 said:

Could use some help with ongoing issue. With my job I drive about an hour then park my truck for about 45 minutes then drive another hour and park it again for 45 minutes and so on. Each time I come out the truck starts fine, the problem is if I stop for a coffee along the way and try to start my truck after only a few minutes of being shut off the truck won't start. It turns over but not enough to start. If I sit there for 15 or 20 minutes it will start (without jumping it). The problem is worse if the outside temperature is hot. I have noticed that the volt meter fluctuates between 12.7ish and 14 which appears to be normal for this truck. My truck has 120,000 miles and the battery is about a year old and was dealership installed. This has been going on for about 3 months ( I only use the truck a couple times a week). I would appreciate any suggestions what might be causing this issue. I'm leaning towards the battery but checking to see of anybody else had this issue and found out it was something other than the battery. Thank in advance! 

I would suspect the battery and since it is a year old or so, should be free replacement if it is an ACDelco battery.  I would put my scan tool on it and look at the start up state of charge and state of charge and battery temperature to determine its health.  The voltmeter moving around is normal, look up the term RVC, Regulated Voltage Control and EPM, Electric Power Management.

 

If all that looked good, I'd look at the starter and make sure the wires are tight.  

[mjm-1957]

Those trucks are known to have battery cables issues. Gm says to voltage drop the ground, positive and also the short positive jumper from the post to the battery fuse block. All should drop less than .5 volt while operating under a load. Have someone hold throttle to floor to turn off injectors and watch your meter while cranking. We change quite a few of them. Especially with that kind of mileage.

[Mark1427]

Thank you I will give that a try, much appreciated. 

[Mark1427]

Thank you Swathdiver I will check the starter cables first. Appreciate the help.

[rlcole321]

Just curious, when you say "It turns over but not enough to start", saying it barely spins over (which would indicate a Batt. problem), or it is the normal cranking speed, but it just will not "fire" up to start?