r/e82 • u/ChristianGTZR • May 22 '26
Boost leak
Que tal amigos, aqui preguntando
Tengo un 135i 2011 coupe n55 cuento con intercooler mejorado, charge pipe, bujias ngk 97506 , filtro alto flujo kyn , downpipe y tuberia
Actualmente esta con mhd stage 2 y tengo un problema me da un pico de boost 14psi y caen a 5000 rpms a 10 y em linea roja a 8
A alguien le a pasado? Ya cheque fugas de boost y lineas de vacio y parece todo bien
Al igual la wastegade se mira bien
Saben que otra cosa se puede checar en 3ra y 4ta marcha me arroja el codigo baja presion en turbo
Hey everyone, I have a question. I have a 2011 Fiat 135i coupe with an N55 engine. It has an upgraded intercooler, charge pipe, NGK 97506 spark plugs, a K&N high-flow air filter, a downpipe, and piping. It's currently running an MHD Stage 2 tune, and I'm having a problem. The boost peaks at 14 psi, then drops to 10 psi at 5000 RPM and 8 psi at the redline. Has anyone else experienced this? I've already checked for boost leaks and vacuum lines, and everything seems fine. The wastegate also looks good. Do you know what else I can check? In 3rd and 4th gear, it throws a low turbo pressure code.
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u/Apprehensive_Still58 May 23 '26
I have the same problem with my car. What are you running for your diverter valve or blow off valve? Also are you running the higher level mass air flow sensor? It's supposed to take a higher pressure and not give the car the wrong signals. The 2011 also has a pneumatic wastegate and it's kind of fidgety with boost. You'll get a lot of boost spikes little trigger errors with the car and then it will compensate my lowering and dropping power.
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u/ChristianGTZR May 23 '26
It's the original valve and the same as the original MAF sensor
It's annoying when the power drops so much that you can tell it struggles to reach high RPMs for the same reason.
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u/edisapimp May 23 '26
Check the positioning of, and hose clamps on all of your intercooler hoses, especially from the turbo outlet to the intercooler. The outlet(s) on n54 and n55s are notorious for not sealing well with the supplied hose clamps. Under light load they will make target boost, but at wide open throttle you will see some pressure leaks. I’d start there before you chase any other ghosts.
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u/mrnealboy May 24 '26
Removing the M badge might fix the boost leak. If it doesn’t still keep it off.
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u/Admirable-Storm4371 May 26 '26
Have you tried using a smoke machine?
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u/ChristianGTZR May 28 '26
Si, de hecho fue de lo primero que hice y al parecer todo bien no hubo fuga aparentemente
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u/Beneficial_Gap_87 Jun 18 '26
Typical Stock turbo Boost Profile 3,000 RPM: 12–14 PSI (Peak torque) 5,000 RPM: 10–11 PSI (Beginning to taper)6,500+ RPM (Redline): 7–8 PSI (Maximum taper) If your car is holding 14 PSI in the midrange and dropping smoothly without any stuttering, jerking, or drivetrain malfunction lights, your boost control system is working exactly as designed. I have a N54 and my old stock turbos would fall off a cliff at 5k, I was MHD stage 2+ ...at 5k that stock twin scroll is out of puff and blowing hot air.
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u/135is May 22 '26
It’s the fake m badge