Engine stuttering, slipping under WOT, no boost.

[Motoarzan]

2014 Sport. Here's the problem.

Under wide open throttle, Flooring the accelerator like when you pass another vehicle...or at least lets say 80% throttle or more.

- Transmission drops a couple gears and the vehicle takes off, RMP's around 4k

- All of a sudden the engine starts hesitating, sputtering, stuttering...like the turbo's are kicking in and out.

-At this stage with the accelerator to the floor it feels like you have little to no boost. the RPM's are only slowly creeping up. Still accelerating but going from 4k-6k RMPS might take another 5 full seconds to get there...all the while the boost stuttering still occurring.

- Even as the RPM's slowly creep up the transmission won't kick up a gear until it finally hits around the 6k, holds there for another second or so then finally switches gears. Even after it gets to the next gear the stuttering problem still continues.

Hears what I know:
- It's not bad gas, I'm on 3rd full tank from 3 different stations in past 2 weeks since this is happening. Always use premium gas.
- Can feel it more when under a heavier load...in gear 4,5,6 when already moving, like merging onto a higway. in gear 1,2,3 driving around city streets you can't feel the stuttering because either it's simply not doing it or the load isn't there being in low gear with lots of torque. However; in manual mode forcing it in 3rd gear I have felt it before.
- NO check Engine lights present, and no codes.
- Brought vehicle to dealer yesterday. They couldn't find anything either but did acknowledge the stuttering problem. There were some vehicle firmware updates and he did them all. Updates did NOT correct problem.
- I've checked the boost hoses and they're good (I know of the problems with clamps coming loose)
- No other unusual issues. Vehicle "cruises" fine on the highway, accelerates fine around city street. No weird sounds, no weird smoke coming out tail pipe ect...Slipping, stuttering only occurs under heavy hard acceleration approaching highways speeds.


Dealer told me to bring vehicle back for more in depth troubleshooting but just wondering if this forum has any ideas on this issue.

 

[1995E]

2014 Sport. Here's the problem.

Under wide open throttle, Flooring the accelerator like when you pass another vehicle...or at least lets say 80% throttle or more.

- Transmission drops a couple gears and the vehicle takes off, RMP's around 4k

- All of a sudden the engine starts hesitating, sputtering, stuttering...like the turbo's are kicking in and out.

-At this stage with the accelerator to the floor it feels like you have little to no boost. the RPM's are only slowly creeping up. Still accelerating but going from 4k-6k RMPS might take another 5 full seconds to get there...all the while the boost stuttering still occurring.

- Even as the RPM's slowly creep up the transmission won't kick up a gear until it finally hits around the 6k, holds there for another second or so then finally switches gears. Even after it gets to the next gear the stuttering problem still continues.

Hears what I know:
- It's not bad gas, I'm on 3rd full tank from 3 different stations in past 2 weeks since this is happening. Always use premium gas.
- Can feel it more when under a heavier load...in gear 4,5,6 when already moving, like merging onto a higway. in gear 1,2,3 driving around city streets you can't feel the stuttering because either it's simply not doing it or the load isn't there being in low gear with lots of torque. However; in manual mode forcing it in 3rd gear I have felt it before.
- NO check Engine lights present, and no codes.
- Brought vehicle to dealer yesterday. They couldn't find anything either but did acknowledge the stuttering problem. There were some vehicle firmware updates and he did them all. Updates did NOT correct problem.
- I've checked the boost hoses and they're good (I know of the problems with clamps coming loose)
- No other unusual issues. Vehicle "cruises" fine on the highway, accelerates fine around city street. No weird sounds, no weird smoke coming out tail pipe ect...Slipping, stuttering only occurs under heavy hard acceleration approaching highways speeds.


Dealer told me to bring vehicle back for more in depth troubleshooting but just wondering if this forum has any ideas on this issue.

Could it be the turbo vacuum hose? Some people have had their vehicles lose power because a vacuum hose came off under pressure under heavy acceleration.

 

[OldSchoolDropout]

Might be too simple...

Did they check the fuel filter? I've seen those same problems before and that was the cause. Basic supply and demand issue.

 

[peterk9]

Recently there have been several members that have hade issues with the throttle body. Quite a few replacements have been done.

Peter

 

[HamHands]

OP, check out what PK9 and 1995E said first. I've had the same exact problem with (2) Ford products and it turned out to be a shot out Crankshaft Position Sensor, or (CPS) for short on Taurus SHO's. I owned two different year ones after one was totaled. And I mean the same exact symptoms, under load, etc, etc... I haven't owned my Explorer Sport long enough to know if the CPS is even a problem or not but then again I hope I never have a problem with a CPS ever again as it cost me lots of money as a broke college kid/athlete 12 years ago... It was to the point I swore I would never own another Ford anything but that was premature, unwarranted, and was neither here nor there. How has the maintenance schedule been followed OP???

 

[Motoarzan]

I'm bringing the vehicle in on Mon and they are going to keep it for a few days for more in depth inspection. I'll mention the suggestions above. The thing is though there are no codes to suggest a sensor. I figured if things aren't all in sync then at least a code would show up. It's under warranty and they're supplying a rental so not too worried. Just hope they find the problem.
I'll report back when and if it's fixed.

 

[Motoarzan]

I'm happy to report the dealer found the problem. It was a cracked vacuum hose at the throttle body.
Work order says:
VACCUM LEAK AT TCBY.
- FOLLOWED PPT HN1 AND HN2 FOUND VACUUM LEAK AT TCBY VALVE. REPAIRED VACUUM LEAK.

They also did a PCM update (I believe unrelated to my original problem). IDS hookup found P0087 & P0234, TSB 14-0105. Wonder what these firmware updates are?

 

[peterk9]

I'm happy to report the dealer found the problem. It was a cracked vacuum hose at the throttle body.
Work order says:
VACCUM LEAK AT TCBY.
- FOLLOWED PPT HN1 AND HN2 FOUND VACUUM LEAK AT TCBY VALVE. REPAIRED VACUUM LEAK.

They also did a PCM update (I believe unrelated to my original problem). IDS hookup found P0087 & P0234, TSB 14-0105. Wonder what these firmware updates are?

P0087 Fuel Rail/System Pressure - Too Low

Trouble code P0234 indicates the powertrain control module (PCM) senses a dangerously high boost pressure from the engine's forced induction system. Levels of boost in excess of recommended levels can compromise the structural integrity of the engine.

For TSB-14-0105 see the following post; http://www.explorerforum.com/forums/showpost.php?p=3386533&postcount=2

Peter

 

[GBot]

I'm happy to report the dealer found the problem. It was a cracked vacuum hose at the throttle body.

You sound like you're describing my problem exactly with the same vehicle, except my 36k warranty just expired of course.

Could you or anyone else here please comment on how difficult it would be to diagnose and treat this problem myself? Or would it actually be covered under warranty?

I was planning on going to the dealer for an oil change tomorrow anyway, so any tips on whether I should have them investigate further or go the DIY route would be great. BTW I'm not an experienced mechanic, but can handle easy to moderately difficult repairs.

 

[GBot]

Correction DIAG REPAIR VACUUM LINE

Tech Notes EEC TEST DTC P0234 DCL DISPLAY FUELPRESSURE TEST 80PSI INJECTOR FLOW 161 TEST IGNITION SYSTEM OK ROADTEST TBIP 38PSI PINPOINT REPAIR VACUUM LINE TO TURBO REGULATING SOL CLEAR DTC ROADTEST OK RETEST OK

$99.95 plus $29.68 to rent a car overnight.

And my 2014 Explorer Sport is back to running good as new. Hope this helps someone...

 

[gatzdon]

I just want to point out for everyone's benefit, OBD Codes are very limited and aren't the only codes in your vehicle.

Right now, Forscan (which is free for the PC and about $5 for your phone) is the only app I know that will pull the extended DTC's from all modules in the vehicle. When investigating an issue, you need to get the codes from the relevant module (in OP's case, the PCM).

When the PCM cuts out the Turbo, there will be a pending code in the PCM with the reason why. As this may not be emissions related, it won't throw an OBD code or illuminate the MIL until it has happened enough times or exceeds a high threshold.

 

[Tony407]

Dropbox - Overboost.jpg

You folks are AWESOME!!! I recently started having the EXACT SAME symptoms as the OP, and having a Livernois tune had me freaked out a bit wondering what could have been wrong (seriously, the symptoms were so dead-on it was something I could have written word-for-word). I too got the P0234 DTC and after a quick search I found this thread. It only took me a couple of minutes to pull the engine cover off and see that one of the vacuum lines had popped loose (swollen hose end) from the resonator(?) to the solenoid/valve looking thing. Put a hose clamp on and took her for a test drive and 100% fixed. THANK YOU EVERYONE!!!!!! -Tony

 

[texsn95]

Which hose was it? Anyone have a working picture?

 

[Mrranggong]

Another thanks for this thread. 2015 Sport with 85K miles stumbling under heavy acceleration. No check engine lights. I assumed I needed new coilpacks as I had just done the plugs. However Forscan said I had code P0234 Overboost condition. Yikes! overboost will grenade an engine in a hurry. prior to poking around looking for the wastegates and wastegate solenoid and hoses so I could check for leaks I did a little research and came across this thread. Turns out when I removed the rear coilpacks to access the plugs I unbolted the big plastic Charge Air Tube and moved it over a little. In the process the hose feeding the wastegate solenoid popped off the nipple and I didnt notice it.

 

[peterk9]

Another thanks for this thread. 2015 Sport with 85K miles stumbling under heavy acceleration. No check engine lights. I assumed I needed new coilpacks as I had just done the plugs. However Forscan said I had code P0234 Overboost condition. Yikes! overboost will grenade an engine in a hurry. prior to poking around looking for the wastegates and wastegate solenoid and hoses so I could check for leaks I did a little research and came across this thread. Turns out when I removed the rear coilpacks to access the plugs I unbolted the big plastic Charge Air Tube and moved it over a little. In the process the hose feeding the wastegate solenoid popped off the nipple and I didnt notice it.

Welcome to the Forum.
Thank you for the post and the pictures. Perhaps it may help someone else.

Peter

 

[texsn95]

So when you reconnected it, did it improve the stumbling issue? Is this the same hose post #12 is talking about?

 

[texsn95]

Well I'll be damned, mine was off too. Just reconnected it, and I swear it feels like it picked up 30hp. I had been fighting some surging and lower power, had even taken videos of the tach bouncing to take to the stealer, and now that I think back, seemed to coincide when I did the plugs sometime last year. Now it pulls much harder and more steady like it did after I bought it last fall. Thanks man!