P0299 underboost please help

shash_128

Registered User
Hi, I have a 2007 2.0t BUL and when the turbo kicks in it sounds different and has not much of a kick. With a diagnostic scanner this code came up. I've changed the dv and smoked tested and found no leaks. Does this mean the turbo is going bad? What's the best way to diagnose it? Thanks
 

I'm Just Rob.

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Also check the turbo wastegate actuator , the rod between the wastegate actuator and wastegate can become disconnected or out of adjustment and you will loose boost, or the actuator can fail .
 

shash_128

Registered User
Hi, its done 111K and hasn't been remapped. I've replaced the N249 valve (diverter valve) with the revision D. I can check the wastegate actuator and rod for any play, but to check the wastegate would I have to remove the cat to get access to the wastegate? If the wastegate is loose is there an adjuster on the wastegate arm to tighten it so it sits flush? Thanks
 

shash_128

Registered User
There is some suction on the oil cap when I remove it while the engine is running. It’s not difficult to remove, is that normal or does the pcv valve need replacing?
 

Yogibear84

Registered User
There is some suction on the oil cap when I remove it while the engine is running. It’s not difficult to remove, is that normal or does the pcv valve need replacing?
I think a slight amount of suction is normal. If your PCV has gone I think you'd feel quite a strong resistance. If its gone you'll probably be running rough and hear whistling from it. I just replaced mine because I'm trying to get to the bottom of a rough idle. It wasn't the PCV but the diaphragm in the old one basically fell apart in my hands while inspecting it
 

Alex banu

Registered User
Check for any air intake hoses +intercooler pipes and itself. I had a driver's side intercooler leaking presure.
 
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