Truck not starting, though battery seems like it's fine

Hey y'all-

I need some help diagnosing a problem. So I've got a 2018 Tundra that wouldn't start this morning though the battery seemed fine (headlights, dash, interior lights, etc are all working). I turn the ignition and nothing really seems to happen except for a "zzzzzzz" sound from the engine (not a clicking sound). I did notice the past 2 days that it took a bit longer for the truck to start but I brushed it off to colder weather. Any ideas on what may be wrong or things I should check before I get it towed to the shop?

Potentially Relevant Info:
Year: 2018
Engine: 5.7L V8
Mileage: ~43,000
Notes: I just drove up from TX to VA (~1,500 mi) last weekend

Any help here would be greatly appreciated!

UPDATE: It was indeed the battery. Thanks for all your help guys!

 

You've probably got a dead cell (loss of conductivity) in the battery. Your 2018 is past due for a new battery based on poll data. Disconnect the battery and attach a voltmeter across the terminals. Your battery should have at least 12.6V. If the voltage is less than that, you can attempt to slow charge the battery. After charging, measure your voltage again after a hour or so with the charger off. If the battery has not charged to 12.6V or higher voltage, have the battery tested.

 

Once you confirm the battery is good, i.e. fully-charged and retains full-charge, you can move on to other possible issues. A dead cell or loss of conductivity is characterized by substantial loss of cranking amps and failure to hold charge. The buzz instead of clicking may say nothing beyond the battery is so discharged, it will not even actuate the starter solenoid.

 

Ah gotcha- I'll test the battery and hopefully that fixes things. Thanks for your advice- I'll let you know how it goes.

 

If it ain't the battery, take it to the dealer and let them mess with it.

 

Agreed. More than likely it’s the battery.

 

another vote for week battery

 

Yup- y'all were exactly right. It was the battery. Went to AutoZone and got it taken care of. Thanks for your help guys!

 

Battery

 

Another crappy Toyota battery bites the dust. Once they start cranking slow but still start it is time to head to parts store. Both Tacomas gave me that warning but not the Tundra.

 

I just purchased a factory 84 month Toyota battery after my 2015 oem started to produce slow start.
Had no is idea of the quality problems. I

 

Always buy the best Battery and Tires you can find.

 

Michelins have been outstanding.

 

Battery cell dead

 

Great street tires but not aggressive enough for my needs