Battery issues, then....weirdness

[Adieu]

2012 Triton 5.4l (Navigator L), ~140k mi

Sat undriven for a few days, maybe a week or so. Somehow totally empty battery, not even enough juice to unlock via remote or jump with a portable jumpstarter. Crud on one of the terminals.

Took out the battery, used a deep cycle charger, reinstalled, started right up - seemed OK

Then....WEIRDNESS

1) lack of power/accelerator response - thought it was just relearning the tranny.... now not so sure
2) what seemed like a shift noise from the 4x4 when I first pulled out of the driveway
3) second time I started it up, no power steering, oil light. Checked oil level --- it was fine --- restarted ok-ish, still some accelerator hesitation
4) fourth time I started it up - same crap with power steering and false oil light
5) then it stalled out entirely as I was shifting into reverse to reenter my driveway. Restarted, "all" fine.


All this on an errand that was like 2 stops and 3 miles.


...what the hell?????? Can an iffy battery or insufficiently clean terminals explain any of this? If not, any ideas?

Thx

PS no other warning lights or notifications, no codes.

 

[jeff kushner]

That IS some weird sh*t.....that may all be explained by a bad ground I THINK...I'm no electrician but I've seen bad grounding do funny stuff and your qualifies as "funny stuff".
Check the neg terminal connections to the engine/frame and start again from the beginning once your taken it off and cleaned it....or do it the "hacks" way to check it by attaching a HD jumper cable Neg to Engine....to supplement the grounding just to check it.

Sucks not having your truck run right....but there's some sharp guys here though
jeff

 

[Black]

Sounds a bit like your alternator is bad/going bad or your accessory belt was slipping.

 

[99WhiteC5Coupe]

A discharged or defective battery (with one or more defective cells) can cause all kinds of electrical issues with modern vehicles.

Ensure the terminal connectors are clean - install a new, high quality battery rated for your vehicle.

Motorcraft makes exact replacements which are good quality.

 

[WhiteFalcon]

I agree with Black. Check your alternator output voltage. Not enough output can cause the computer to do strange things. I had a car once refuse to shift out of third. Thought it was the tranny, but it turns out it was the alternator going out and computer was giving bad commands to the transmission.

 

[jeff kushner]

Let's see, it's 630 on the E coast so it's 330 there and it's Friday so you should have left work at noon although you could have been slammed in traffic....so, get into the truck yet or starting fresh in the morning?

jeff

 

[Adieu]

Seems like it does this only when shifted into reverse.... and yup it's still a thing

Shift to reverse, truck stalls out, oil symbol appears next to odometer

After restarting usually works

Wth? Ideas? Thx.

 

[Adieu]

Fixed! Forgot to report conclusions:

It's just some kinda vacuum leak, one or more of these was the culprit:





Considering the price and the "just reach in with a glove" toolless swap, I didn't bother figuring out which one was at fault. Highly likely I might have accidentally whacked and damaged one of em while swapping plugs a month

As to the battery... Walmart house brand product reliability. Lol.

 

[jeff kushner]

On both of my 5.4's, the passenger side vac hose(6" towards the front from the firewall)....right where the molded rubber turn is.....it rubs against the valve cover and wore through...causing a crappy idle but fine otherwise......real easy to find....sliding fingers around hoses while it's running....it's pick right up when you cover the hole...

jeff

 

[WhiteFalcon]

Glad you you found the fix!