P0234 Overboost 2015 Sport

[Allan McBride]

Hello, I am hoping some of the wisdom on here can help me trouble shoot my Ex. Over the last few months I have been experiencing this subtle issue where everything seems fine, get on the throttle and smile, then after whenever I get on it no power. I can hear the waste gates opening. I don't have a CEL so I checked with my scanner and I found P0234 overboost. I checked all the hoses and ran the system gage. Just as I felt, I maxed out at 11.45psi and then after that I couldn't get over 2.5psi. I had this happen to my BMW 335i, almost identical symptoms but would get a CEL and replaced the boost controllers and it fixed it. As far as my searching has gone, i cannot find a part or location for a boost controller.

Your thoughts or advice is appreciated.

 

[peterk9]

Welcome to the Forum Allan.
I don't know if this thread will help.

Engine stuttering, slipping under WOT, no boost.

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...

www.explorerforum.com

Peter

 

[Allan McBride]

Welcome to the Forum Allan.
I don't know if this thread will help.

Engine stuttering, slipping under WOT, no boost.

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...

www.explorerforum.com

Peter

GOOD NEWS! I was able to locate and fix the issue. It was actually very simple but extremely hard to see. A hose from the charge pipe had come off and was burried. The image below is from the Youtube video I used to find it.

 

[bigpal]

I know this topic has been discussed before - I have done quite a bit of research in trying to fix this problem of mine, to no avail. I have a 2016 Explorer Sport with 80k miles, and immediately after purchasing brand new in late 2015 I added a Livernois tune, K&N intake system, Livernois 160 thermostat, and Livernois Map Sensor. I usually run the vehicle with the Livernois 87 tune, sometimes the 91 tune, but I haven't done that since fuel became ungodly expensive. As a troubleshooting step, I loaded the OEM tune and experienced no change in the symptoms.

I took the vehicle to my local dealership. They were awful. I cleared the code before I went, but on the way there, it had the overboost condition based on the sounds coming from the engine and waste gate. The dealership simply cleared the DTC and told me everything was fine. They drove it, but obviously didn't get on the throttle, which is why it didn't throw the DTC again. Unbelievable. On my way home, it threw the DTC.

I pulled off the engine cowling and examined the typical hoses going to the solenoid. One hose was possibly loose, so I put a hose clamp on it. Same problem. I don't believe the waste gate is stuck, as I can hear it opening and closing, and sometimes at WOT it just stays open and you can hear steady air leaving the turbo. I'm now at a point where I want to start replacing parts to fix the issue. I think the map sensor and boost preessure sensor to start.

I'm looking for any help or input on this. There could also be other hoses I can't see that are loose.

P0234 Overboost Condition​

 

[mguy13sport]

The code should tell you which bank it is. Its either Bank A which is front turbo or Bank B which is rear. The rear charge pipe is buried and it could be lose. When you returned to the stock tune you would need to put the OEM map sensor back onto the intake for things to run properly - not sure if you did that already. What boost readings are you getting and what are you using for data logging?

 

[bigpal]

The code should tell you which bank it is. Its either Bank A which is front turbo or Bank B which is rear. The rear charge pipe is buried and it could be lose. When you returned to the stock tune you would need to put the OEM map sensor back onto the intake for things to run properly - not sure if you did that already. What boost readings are you getting and what are you using for data logging?

Sorry, I didn't get a notification of your response. I've done a few things since this last post of mine. I put in the stock MAP sensor, and tried a new sensor. I've also replaced the boost solenoid, twice. With any/all of these fixes, there was no change in bad behavior. I ran the Forscan lite app on my phone and it is saying "Supercharger A", so I would assume that is the front. I'm not entirely sure how to check and log the boost, but I know it's done via Forscan dashboard, I just don't know the proper PIDs to add.

The only thing the DTC gives me that seems relevant is "-MAP: 176.0 kPa - Manifold Absolute Pressure sensor (which I believe translates to 25 PSI).

In another post I saw a Ford tech identified a pinhole leak in a turbo vacuum line. I'm wondering how you would identify that, since the old soap and water doesn't work on vacuum lines, but only pressurized lines. I have a feeling I have a small leak I can't see with the naked eye.

 

[mguy13sport]

Check the linkage on the front turbo wastegate. There is a metal rod connected to the wastegate which can come lose or fall off entirely which will cause boost leak

 

[bigpal]

Check the linkage on the front turbo wastegate. There is a metal rod connected to the wastegate which can come lose or fall off entirely which will cause boost leak

Here is a picture of the turbo from the 3.5L I found. Is the linkage you speak of circled there? I'll look again but I can't see much, maybe I need to put the car up and go under?

 

[mguy13sport]

That is it

There is a PID to monitor waste gate duty cycle load. If its always reading 0 it usually means the wastegate is having issues

 

[Ciscokid8]

Hello,
I have a 2015 Sport and recently I've had off and on odd ball electrical issues and turbo lag. For some reason the airbag light randomly comes on and the turbo lag and hesitation goes away. When the airbag light goes off on its own, the lag and hesitation comes back.
The car will not remote start but will usually start by the interior button press or will say no key detected while in the car with the key, then I'll place the fob in the center consul spot and it starts. Last night the alarm started sounding about every hour for no reason. When I get into the car there Screen shows shutting down to save battery even though there is a new battery in the car.
My wife took it to a mechanic while out of town a couple weeks ago and he said there was a P0234-00 code- Turbo/Supercharger "A" over boost and quoted her $4000 and it was critical or she wouldn't make the two hour trip home... I didn't go for it.
Are any of these things familiar to you guys?

 

[peterk9]

Hello,
I have a 2015 Sport and recently I've had off and on odd ball electrical issues and turbo lag. For some reason the airbag light randomly comes on and the turbo lag and hesitation goes away. When the airbag light goes off on its own, the lag and hesitation comes back.
The car will not remote start but will usually start by the interior button press or will say no key detected while in the car with the key, then I'll place the fob in the center consul spot and it starts. Last night the alarm started sounding about every hour for no reason. When I get into the car there Screen shows shutting down to save battery even though there is a new battery in the car.
My wife took it to a mechanic while out of town a couple weeks ago and he said there was a P0234-00 code- Turbo/Supercharger "A" over boost and quoted her $4000 and it was critical or she wouldn't make the two hour trip home... I didn't go for it.
Are any of these things familiar to you guys?

Your thread was merged with this existing one on the over-boost issue.

Peter