Hi y’all
I have a 2015 f150 xlt 2wd 5.0 flex fuel that have around 130k miles

I look everything online and a lot of folks have this issue with the f150

I been having issues where at idle the car will stall or shudder and sometimes it will die . The rpm will just drop low on its own. Sometimes it adjust it self and sometimes it doesn’t and it happen randomly and not on every idle . Some days are fine and some are not and there is no check engine light at all.

I read and did research for months and so far I changed :

1-VCT solenoids all of them
2- cam sensors all of them
3- crank shaft sensor
4- ignition sensor
5- new spark plugs, coil boots and springs
6- lead frame for the transmission and new oil
7- mobile one synthetic oil for the truck
8- o2 sensors all of them
9- new purge valve
10- new throttle body
11-new air filter
12- I used that crc valve cleaner thing that you spray in ur throttle body and it suppose to clean ur like injectors and valves and such

That all I can think of now and it still does it

I really don’t know what else to do or to look for anymore as this damn problem is driving me insane

thank you

 

Have you looked for any codes or pending codes?
I would suspect that this kind of problem would generate a code.
If you have Forscan you can monitor key PID's to help diagnose the problem.

 

no codes and no pending codes either. Some people saying it might be the vct phasers ? Not sure honestly but I am getting fed up with this truck

 

Doing the phasers is a big job costing $$$.I would be hesitant to do this without a code.
Any problem in the VCT will throw a code as the PCM monitors this system very well.
You can verify the VCT performance by monitoring the PID's on Forscan.
Without a code this will be very tough to troubleshoot.
Typically the VCT stalling issue is only after warm-up and occurs when coming to a stop or just idling. It always throws a code and eventually the light on the dash.
At least this has been the case on my 2017 5.0.

 

i do all the work usually my self I changed the vct solenoids and did everything my self . And that’s exactly what it does when it’s warm at a stop or a light it will stall and die or it will struggle and correct it self but no lights on the dash at all and no lights came on

 

The engine has enough miles to possibly be coked up under the intake valve heads. Worn intake valve seals etc, PCV valve dirty etc. letting to much oil into the intake and even gas quality.
Run a couple tanks of gas through with fuel additive to help clean off the accumulation.
As soon as even a small roughness is detected I use one bottle REGAIN product which is even weak dilution in full tank of 26 gallons.
You may need more over a longer period to clear or reduce your possible carbon build up.
There are several levels, use the one that covers the most possible issues.
Worth a try for the cost.
Works for me and I don't have stalling or any Idle variation hassle just a light feel of instability after a while, when it's needed..
Good luck.

 

I tried the crc valve intake clean up which stated rhat it clean the valves and everything from carbon buildup and it didn’t fix it but it also worth a try. The only problem is I can’t seem to get anything inside the stupid tank even if I use a king cone the liquid doesn’t seem to go down so I don’t know if I need a special cone ?

 

I finally got a pending code this morning after stalling few times is P052C

any idea on that? Is that basically the vct phasers or the actual vct? Cus the vct selenoids are new

 

P052C is non-specific meaning the PCM sensed the camshaft was over advanced. This could be the result of several things but since you replaced many of them it narrows down to the timing chain, phasers and/or an oil problem. These motors are really picky about oil. Should be 5W-20 Synthetic Blend with a ILSAC GF-6A rating such as the Ford stuff.

When you replaced your solenoids was there any excess tarnish build-up? There are tiny filter screens inside the camshaft that feed the phasers. If these have crap in them it’s a problem. If your motor insides were pretty clean then you’re probably OK.

I think the 5.0 phasers are pretty robust. But if you got a tarnish thing going on it’s bad news.

At least you know it’s bank 2 or the driver’s side.

I think your best bet is getting Forscan setup to monitor the VCT pids for bank 2. This is under the oscilloscope section.
It’ll look something like this:



What’s important are the ranges not so much the wiggly lines. As you can see the all important oil pressure is the top line and is averaging about 12 PSI – good. The key indicator is VCTSYS (the blue line) which shows the system is closed loop meaning the PCM thinks it has control of the system. The VCT_INT_DIFFn lines shows the difference between the commanded valve position and the actual position. If these are not within a couple degrees it mean there's a problem. Mine were going out like 30 to 40 degrees when the solenoid was acting up. The other lines show the actual advance or retard of the camshafts. Note these traces are not showing all the camshaft because there’s not enough room. You have to go through both Intake and exhaust for each bank. Also, these traces are a known good system. The actual values for these PID’s for various conditions are noted in the service manual. This is a great tool for figuring out whether the VCT system is working correctly are not.

I would not dig into the phasers or timing chain until you determine for sure that’s the problem. If you do be sure to replace those filter screen in the camshaft. There are four of them!

 

thank you for the great info. How can I get that software to scan and such? it might be working investing on one. And when I changed the solenoids there was just regular oil residue . I change oil every 5k miles with fully synthetic mobile 1 5w-20. When I opened the valve cover I really didn’t notice those or see those filters there. The idle got worse today and then it threw that code that I mentioned . I am also gonna run some sea foam in the oil just to clean up any extra **** that I can’t see but usually the oil is not bad in color and the valve cover looked pretty good to me from inside .