Loss of boost, poor idle and jerky throttle response

[FiestaSTdude]

I was driving on the highway today and after about 30 minutes my fiesta all of the sudden lost boost (I could only make 1lb) and it started being jerky when I shifted or let off the throttle. I thought it was a vacuum or boost leak, but it went away after I turn the car off for a couple minutes.
My car has a p0238 and p025e code at the moment and earlier I had a p0236 code. All these codes share the boost pressure sensor as a possible source so I bought a new one to replace it. To me, it seems like the engine isn't getting some of the information it needs to run correctly causing it to be jerky. Any tips for what to diagnose would be appreciated and I will update if I find a solution.

 

[TyphoonFiST]

I was driving on the highway today and after about 30 minutes my fiesta all of the sudden lost boost (I could only make 1lb) and it started being jerky when I shifted or let off the throttle. I thought it was a vacuum or boost leak, but it went away after I turn the car off for a couple minutes.
My car has a p0238 and p025e code at the moment and earlier I had a p0236 code. All these codes share the boost pressure sensor as a possible source so I bought a new one to replace it. To me, it seems like the engine isn't getting some of the information it needs to run correctly causing it to be jerky. Any tips for what to diagnose would be appreciated and I will update if I find a solution.

Check hotside intercooler to turbo hose*

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[FiestaSTdude]

Check hotside intercooler to turbo hose*

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All my hoses are fine.
I cleaned these two sensors, I'll report back if that helps. I'm doing a bunch of other stuff to the car, so it won't be running for a couple days.

 

[FiestaSTdude]

All my hoses are fine.
I cleaned these two sensors, I'll report back if that helps. I'm doing a bunch of other stuff to the car, so it won't be running for a couple days.

My new boost pressure sensor came today, so I'll see if that fixes anything.

 

[FiestaSTdude]

My new boost pressure sensor came today, so I'll see if that fixes anything.

Well, I went for a two minute drive and I can definitely say the boost pressure sensor didn't fix it. Still sounds like it has a boost leak (I can hear the turbo whistling) and still drives like crap. Accessport shows I'm way down on boost. Plus I now have p007D, p0234, and p050E, in addition to p0236, p0238, and p025E. 😡

 

[akiraproject24]

Well, I went for a two minute drive and I can definitely say the boost pressure sensor didn't fix it. Still sounds like it has a boost leak (I can hear the turbo whistling) and still drives like crap. Accessport shows I'm way down on boost. Plus I now have p007D, p0234, and p050E, in addition to p0236, p0238, and p025E. 😡

completely spit balling here....intercooler catch a big rock, bypass valve stuck open partially? boost controller failing.

 

[FiestaSTdude]

I doubt anything happened to the intercooler, but I'll definitely look. Where is the bypass valve? The boost controller came up in something else I was reading, so that is going to get investigated.

 

[akiraproject24]

I doubt anything happened to the intercooler, but I'll definitely look. Where is the bypass valve? The boost controller came up in something else I was reading, so that is going to get investigated.

On the turbo itself. If you still have the OEM I believe they call it a bypass bpv instead of bov as it recirculates the pressure back into the intake

 

[FiestaSTdude]

On the turbo itself. If you still have the OEM I believe they call it a bypass bpv instead of bov as it recirculates the pressure back into the intake

Thanks, yeah, I'm still oem as far as I know. I might just replace the bpv. I have had boost pulsing issue for a while and I'm wondering if this new issue is related to that.

 

[Sam4]

completely spit balling here....intercooler catch a big rock, bypass valve stuck open partially? boost controller failing.

Putin's impeller

 

[FiestaSTdude]

Could the boost control solenoid be shot? I need to double check the lines to it.

https://www.partsgeek.com/catalog/2017/ford/fiesta/fuel_delivery/turbocharger_boost_solenoid.html

What should I look for to tell if the BOV is bad? Should I pull it off the car?
Also if its bad, I'll obviously be getting an aftermarket one. Any recommendations for a good BOV for the stock turbo? I don't want anything that will require constant attention, louder noise is fine but I don't have to have it.

 

[Lays]

Did you already check your PCV hose?

My friend had his PCV hose pop out the other day, and had no boost + poor idle + crappy throttle response and whistling noise.

 

[akiraproject24]

Could the boost control solenoid be shot? I need to double check the lines to it.

https://www.partsgeek.com/catalog/2017/ford/fiesta/fuel_delivery/turbocharger_boost_solenoid.html

What should I look for to tell if the BOV is bad? Should I pull it off the car?
Also if its bad, I'll obviously be getting an aftermarket one. Any recommendations for a good BOV for the stock turbo? I don't want anything that will require constant attention, louder noise is fine but I don't have to have it.

I like what Lays mentioned. As far as bov turbosmart 50/50 (more noise) or their plumback....these will require a CEL defender plug though. I went with a turbosmart Veeport which goes into where the resonator sits off the cold pipe, the nice part about it is its easily accessible BUT you will need to still CEL defender AND a block off plate on turbo. Ive not dealt with the oem failing to really speak to it other than reading about symptoms and such on here.

 

[FiestaSTdude]

Did you already check your PCV hose?

My friend had his PCV hose pop out the other day, and had no boost + poor idle + crappy throttle response and whistling noise.

Haven't checked it yet, thanks for the suggestion. Definitely going to do that now.

I like what Lays mentioned. As far as bov turbosmart 50/50 (more noise) or their plumback....these will require a CEL defender plug though. I went with a turbosmart Veeport which goes into where the resonator sits off the cold pipe, the nice part about it is its easily accessible BUT you will need to still CEL defender AND a block off plate on turbo. Ive not dealt with the oem failing to really speak to it other than reading about symptoms and such on here.

Thanks!

 

[TyphoonFiST]

Haven't checked it yet, thanks for the suggestion. Definitely going to do that now.

Thanks!

Do you have an OCC? if so....check those hoses also as the tend to rub and create a boost leak points.

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[FiestaSTdude]

Do you have an OCC? if so....check those hoses also as the tend to rub and create a boostvleak point.

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No, I don't. That's actually part of the reason why I took it out.

 

[FiestaSTdude]

I checked the pcv lines and looked at my boost lines again and nothing appears to be disconnected. I also looked at the lines for the boost controller solenoid.

I guess I'm going to order a new BOV and maybe a boost controller solenoid.
https://whooshmotorsports.com/colle...art-bov-kompact-dual-port-ford-fiesta-st-1-6l
here's the BOV I'm going with

 

[Business6]

I like what Lays mentioned. As far as bov turbosmart 50/50 (more noise) or their plumback....these will require a CEL defender plug though. I went with a turbosmart Veeport which goes into where the resonator sits off the cold pipe, the nice part about it is its easily accessible BUT you will need to still CEL defender AND a block off plate on turbo. Ive not dealt with the oem failing to really speak to it other than reading about symptoms and such on here.

TS doesn't sell the CEL defender anymore, last I checked. Not sure what the hell you're supposed to do in a state with emissions now.

 

[TyphoonFiST]

TS doesn't sell the CEL defender anymore, last I checked. Not sure what the hell you're supposed to do in a state with emissions now.

Time to MOVE* That has always been a racket.....As liberal as Mn is they figured it out hat it was just another way to tax people and the data showed that it didn't harm the Environment without them as the cars run so clean now anyways and proceeded to shut all the stations down.

 

[akiraproject24]

TS doesn't sell the CEL defender anymore, last I checked. Not sure what the hell you're supposed to do in a state with emissions now.

Damn, hope mine lasts the life of the car lol.