Ex sport dumping boost partial throttle

[Xkrexplorer]

Hello all,

Currently 8000 miles on a 2014 ex sport. Vehicle has down this since day 1. Reason I am posting this is I just vented my bypass valves to atmosphere and the issue is much more noticeable now that it is easily heard. Before I would just feel the problem, now I feel and hear it.

Under partial throttle and at or below 2000 rpm, no matter what speed, and under a load such as going up a hill (highway or road), the car goes in and out of power. What it is, is the bypass valves (blow off valves) dumping boost in the charge pipe. The valves dump boost constantly over and over again until I am either no longerunder load or give it more throttle. If it downshifts by giving it more throttle, it all goes away.

Was wondering if anyone has noted this and if not if anyone can go out and replicate this.

The truck is modified with corsa exhaust, downpipes, diablosport 87 tune, k and n CAI, and bypass valves vta. But it has always has done it. May have gotten a little better actually with the tune.

My theory is that ford is keeping the turbos spinning at low throttle to prevent lag, the engine doesn't need all that boost at low throttle and low rpm, so it dumps, turbos still spinning and so the process keeps repeating itself over and over. I have noticed guys on the f150 site noticing the same thing. It is really noticeable with the bypass valves vented to atmosphere. It is only a very specific part of the throttle, when the waste gates are closed and turbos are going under a load, but engine can not use all the boost.

Any thoughts?

 

[Dr Plastic]

Check the ducts that are attached to the turbos. There is a problem with them blowing off and causing the problem you are having

 

[HamHands]

Check the ducts that are attached to the turbos. There is a problem with them blowing off and causing the problem you are having

Do you know of any pics that show what you are describing? I'm new to the platform but can turn wrenches with the best of them... I'm not experiencing the problem but would like to know exactly where to look to see if I ever do. This is my first twin turbo vehicle... Thanks!

 

[Dr Plastic]

None that I know of. But you can check by crawling under the car and checking the ducts that go from the turbo to the intake manifold. The Sports have been having this ongoing problem for some time. I think the clamps were not tightened properly on the assy line. Others that have experienced this should pipe in and explain it better.

 

[Xkrexplorer]

Thank you for the replies. All of my ducts are fine. The truck runs like an animal under full throttle and I think if there was a leak it would be worse and fall on its face.

This is when it happens if anyone wants to see if it happens on their truck. On the highway, get up to 60 or 65 and then approach a descent hill on the highway and do not let the transmission down shift, just gently add throttle to try to maintain your speed on the hill. Or on a country road at 30 mph, that is flat and approach a descent hill, without letting the car down shift and ease into the throttle and try to maintain a speed of 30 or so. It is subtle without the bypass valves vented to atmosphere since it is muffled by the re-circulation, but you can feel the truck through the steering wheel, gas pedal, and your seat act confused and surging ever so slightly as the boost cycles up and down. If you are vented to atmosphere, you can hear the blow off valve cycling repeatedly.

It seems to be the "tip in" of giving the car a load to get into boost, but the boost is too much for the engine to use so it dumps and cycles repeatedly. If the truck downshifts, there will be no issue.

 

[HamHands]

None that I know of. But you can check by crawling under the car and checking the ducts that go from the turbo to the intake manifold. The Sports have been having this ongoing problem for some time. I think the clamps were not tightened properly on the assy line. Others that have experienced this should pipe in and explain it better.

Thanks Doc, I will do just that. Are the hose clamps the kind of aluminum or steel bands that have teeth marks in them that tighten by rotating a screw clockwise; like found on most radiator hoses??? If so I don't think it would be a bad idea to tighten them just a tad more? I'm also thinking of putting some witness marks on them as well with a white paint pen so I can easily see if they have loosened between oil changes, etc...

 

[blwnsmoke]

Thanks Doc, I will do just that. Are the hose clamps the kind of aluminum or steel bands that have teeth marks in them that tighten by rotating a screw clockwise; like found on most radiator hoses??? If so I don't think it would be a bad idea to tighten them just a tad more? I'm also thinking of putting some witness marks on them as well with a white paint pen so I can easily see if they have loosened between oil changes, etc...

Yes, those are the ones.

 

[dinges77]

Thank you for the replies. All of my ducts are fine. The truck runs like an animal under full throttle and I think if there was a leak it would be worse and fall on its face.

This is when it happens if anyone wants to see if it happens on their truck. On the highway, get up to 60 or 65 and then approach a descent hill on the highway and do not let the transmission down shift, just gently add throttle to try to maintain your speed on the hill. Or on a country road at 30 mph, that is flat and approach a descent hill, without letting the car down shift and ease into the throttle and try to maintain a speed of 30 or so. It is subtle without the bypass valves vented to atmosphere since it is muffled by the re-circulation, but you can feel the truck through the steering wheel, gas pedal, and your seat act confused and surging ever so slightly as the boost cycles up and down. If you are vented to atmosphere, you can hear the blow off valve cycling repeatedly.

It seems to be the "tip in" of giving the car a load to get into boost, but the boost is too much for the engine to use so it dumps and cycles repeatedly. If the truck downshifts, there will be no issue.

Ever figure out the issue? I'm having the same problem.

 

[peterk9]

Ever figure out the issue? I'm having the same problem.

The member you quoted was last seen here July 1, 2016.

Peter