Hello everyone, I am a new member here. Thanks for the add. I am in need of some assistance. I have a 2015 2.7L that is having turbo issues that no mechanic really wants to help me with. Here is some context. Last week I was on my way out of town to go hunting, I was pulling a trailer, when my truck just randomly went in to LIMP MODE on the highway. I pulled over in to the next town, that was only a mile away and went to Oreilys. Had them pull the codes and the gentleman at the counter said he was pulling a code for my TURBO P0299. I turned the engine off and waited and then started her up and the wrench icon went away. I started driving on the highway again and I could hear what could only be described as a jet engine coming through the dash lol. Every time I would push the gas and the turbo would engage on the driver side it sounded like my truck was going to take flight. First thing that came to mind was that there is a leak in the line somewhere. I pulled over again and checked the lines, no cracks, nothing disconnected, checked the boots, they looked good, checked the oil, oil is good. I am not sure what the problem could be, but the turbo is letting out a really loud hissing/air sound and loosing boost. Any help would be greatly appreciated, because mechanics seems to be scared of these things. I know I can take it to the dealership, but I am trying to avoid handing over my first born as payment to the dealership. Much appreciated.

 

thats an underboost condition which would go along with the noise. Being that you have that noise on the driver side I would say it sounds like you missed something from the outlet of the turbo (intake side, not exhaust) from the turbo to the intercooler. Putting that into google brings up several previous threads on this forum as well as youtube videos that show people checking all the charge piping.

Sound can do funny things though, could be from anywhere in the piping system.

 

Sure sounds like boost is blowing off to atmosphere. Go back and recheck tube/hose connections between turbos and throttle body for one that’s loose.

 

P0299 - Turbocharger/Supercharger Under-boost Condition

Description:
This DTC sets when the actual TCBP (TurboCharger Boost Pressure) value is less than the desired TCBP value by 27.6 kPa [4 psi] or more for 5 s, indicating an under-boost condition.

Possible Causes:

• Damaged TC wastegate regulating valve solenoid
• TC wastegate regulating solenoid valve stuck
• Wastegate stuck open
• Wastegate control hose open or plugged
• Air leak between turbocharger and throttle

 

so it's most likely a wastegate issue?

 

I don’t believe the waste gate would account for the noise you’re describing

 

Question for everyone - could this be the turbo bypass valve leaking/opening? Does "P0299" reflect a specific turbo? Is it "limp mode" or just a large loss of power (boost)?

 

Sorry, it is for Turbocharger-1 which is passenger side. Nothing says that the PCM actually goes into "Limp Mode" so it is likely just the loss of power. With the noise you are hearing it is likely a piping issue between the turbo and the throttle body.

 

The Ford WSM I have for my ModelYear 2015 2.7 indicates P0299 is "Turbocharger/Supercharger A Underboost Condition", "A" referring to the sensor in the intake air just prior to the throttle body. This would not be specific to only one turbo (driver-side or passenger side). "turbo bypass valve issue? if not piping leakage.

 

This video is for 2013 3.5 Eco BUT almost all of the diagnosis is still applicable