A friend of mine has a x50 with 24k miles and it only pulls to .4 bar in 3rd or 4th it runs great and no codes but will not go past .4. He has tried disconnecting the battery, should it just have a boost leak test or would that be DV's?

 

How do you know there are no codes? Did you use a PIWIS, PST2 or durametric? There does not have to be a light on for codes to be logged. The possibilities are leaks, DVs, wastegates...etc.

 

Durametric shows no faults stored.

 

Like wross advised, check boost hoses, especially around the intercoolers and diverter to hose connections, sounds like a boost leak somewhere.

 

Leakage. Check your seals, DVs, connections, and look for splits in the hoses. The stock F-hose has been known to split.

 

.4 is typically referred to as "limp mode" which is what the car goes into when there's a leak...It was designed into the computer to protect the engine and to alert the driver that something is wrong. Blowing a hose off the intercooler will cause this...F hose leaks or poor/loose hose fittings will cause it. Did your friend do anything to the car recently....like, install diverter valves etc? If so, check the recent work, If not, then look for the leaks.

BTW....if it turns out to be a hose to the intercooler or boost hose....don't be afraid to spray a little WD40 on the connection and wrestle the hose back into the connection till you hear it click. I spent hours taking everything apart and messing with the wire clip...then took it to an indy who simply grabbed the hose intercooler hose, jammed it in and yanked on it like he was pulling a bad molar...and I heard the wire clip "click" as the hose snapped into place. He did in one minute what I had taken hours to fiddle with because I was using a white glove approach.

 

my first guess would be a boost leak, definitely check that

 

Thanks, he dropped the car by so we'll check for loose hoses and then do a pressure test. I was wondering why it just stayed at .4 but that answered my question that a boost leak can send it to limp mode. Thanks again

 

ok, no boost leak and no codes? could it be dv

 

I would check DV's and wastegates. and I would check them pronto. Check the wastegate adj nuts.

 

last time mine did this one of the actuator rods was broken and it was running on one turbo.

 

rods look fine, could he have a bad turbo? and how would you check one?

 

Easy, just take of the intake pipe going into the compressor housing inlet and look at the wheel for damage. You will also want to check the shaft play by holding the center of the wheel and moving it up and down.

 

Check for boost leaks before suspecting a bad turbo, its far more likely.

 

Similar problem here, except I was hitting 1.0 bar yesterday. Could there be something wrong, its a stock turbo S.