tonhe

So, I just purchases a 2012 F150 SuperCrew with the 5.0L V8 last week with only 19,000 miles. After I got it home I started to notice a "pulse" when I lift off the brake at a stop. It doesn't always do it, but it does do it quite regularly.

Does anyone else have this issue? Is it normal? I've never had a car/truck do this before and I thought it was odd.

tonhe

Anyone have any ideas?

⋞⑀⍕∍⋌⋋l⍕⑁⋟

Thats just one of two things which are normal. 1. If your wheels are cranked off when it happens its just the differential doing what it do and turning your tires at different speeds and if you have LSD the diff is locking. 2. These trannys shift very softly and will flutter upon engagement and during low throttle upshifts. Especially 1st and 3rd. Unless you mean something else by pulsing. But i assume you mean sort of like a gentle shudder or hop. Almost imperceptible unless your paying attention

tonhe

I guess I'll try to explain the pulsing better to ensure it's not an issue....

This happens when my wheels are straight and I'm sitting at a stop light or a stop sign and I lift off the brake without giving it any gas... the truck instead of slowly crawling forward kinda moves forward in pulses... Not sure how to explain it better than that.

⋞⑀⍕∍⋌⋋l⍕⑁⋟

Thats what mine does to. Im sure its the same thing. I dont think its a malfunction.

⋞⑀⍕∍⋌⋋l⍕⑁⋟

Or wait if you completely release brake or kind of creep off of it?

mrgooden

Press your brake pedal repeatedly hard while staying in drive. My 12 5.0 did that as well, I traded the truck for a 13 Ecoboost. The stupid ford dealership tried to say it was not repeatable. I was like really? Come with me. Next they said it was fuel sloshing in the tank. I said can we take the stupid hat off. They contacted ford, said something with transmission. I'm like vacuum has nothing to do with the transmission for letting off the brake. My personal thougjts were to regap plugs and go from there, but traded it before...

Richard

Buster Saunders

^^ haha, fuel sloshing in the tank.

Mine does something like this when coasting downhill. Say if I'm in manual 2nd coasting down a hill sometimes lightly on the brake, my truck will "pulse". You can see it on the tach.

Buster

Gene45

2012 scab 5.0 does something similar when starting out gently. A small surge, I'm not worrying about it as it seems like the computer is just adjusting to the changing conditions.

I had a 2005 subaru that "surged" going downhill with cruise control on. I went back to ask whether that was a problem. When I found a guy at the dealership who knew how it worked, it seems the the computer shuts of the fuel to some, or all, cylinders when the speed gets too high.

We don't really understand how the systems are all integrated.....
Hopefully someone does.

redfred

My 2012, 5.0 has had the surging at very light acceleration, had only done that a very few times. However one time taking off from a stop sign i accelerated and the truck went flat, no power and started jerking, after nearly getting run over, the truck picked up and would not do it again. There was no check engine light, I then took it to dealer and there story was OF COURSE no codes and bring it back if it does it again. Has not gone flat again but occasionally does the light surging especially if i'm driving slow in a parking lot. If thats all it does, i'm ok with it.