1.4T tuned..BOV issue.

[Nemesis]

Hey guys! I have the absolute weirdest issue and I'm hoping someone has come across it.

Driving on the highway after some time (usually an hour or more) will cause me to lose boost. No error codes come up no CEL. I just have the inability to generate more than 1-3 psi boost. (gauges tell me) not to mention I can floor it and nothing happens. It's like it's leaking out the BOV or something..

Here's the crazy part - I pull over. Turn the car off... Turn it back on 20 seconds later and we're back to life with full boost. Everything is as it should be.

My tuner at Nextmod doesn't know what it could be they've never worked on a Sonic to this extent. So I'm trying to bring him any information possible.

Can you guys help with this? I'm so damn lost on this issue.

 

[Jaredg]

I've had vacuum lines blow off that cause this issue but Ive never heard of it fixing itself. Sounds like the computer is sensing something it doesn't like and is limping the boost. Any CEL codes?

 

[Nemesis]

I've had vacuum lines blow off that cause this issue but Ive never heard of it fixing itself. Sounds like the computer is sensing something it doesn't like and is limping the boost. Any CEL codes?

No codes whatsoever :/ turn off the car turn it back on...Boost is back LOL that's why I'm beyond confused.. gonna have to do some logging with my Turner's logger I think on this one.

 

[KatSeagull4.7]

It's going into limp mode. Look at freeze frame dtc display and see if you have overboost codes. Same thing kept happening to me on the highway because the comp detected overboosting. Limp home on these cars lock the throttle at 47% and no more than 5psi of boost will be generated.

 

[KatSeagull4.7]

As for the bov issue which spring do you have in it(Green or Yellow)? Assuming it's the forge one.

 

[Simplyjesse]

Something in the ecu is telling it to do this. It's a little too vague to diagnose without a scan and even then I don't know if I am qualified enough to know. I'm just spit balling, I'm no pro. My thoughts would be possibly
A) intercooler heat soak
B) not running high enough octane
C) torque limit not raised high enough on tune

 

[Mincemeat90]

I’m having issues whit my new turbo I just installed. Apparently the ECU isn’t responding to the new turbo and i have oscillating boost ans sounds like I’m taking a lot of air in and it’s whining. I cleaned all the sensors and still the same. Shits weird

 

[Simplyjesse]

Sounds like a boost/vacuum leak somewhere. The oscillating boost is the same as oscillating idle correct? Double check all your hoses, oil return line, pcv. Do a boost leak test if possible.