Vacuum line between Actuator and Solenoid Valve !?

[540i to MS6]

Is there is supposed to be a vacuum line connecting the wastegate actuator to the wastegate solenoid valve?

There are plugs on both the nipples. I think the previous owner is forcing the wastegate to be closed and controlling all boost levels with the BPV.

1) Am I correct?

2) Is this safe?

3) Should I put a vacuum line between these?

I can post a picture if you like.

 

[banzairx7]

So there is no line hooked to the wastegate actuator? If so that is VERY bad. You must be losing boost somewhere or the turbo is on it's last legs. Otherwise you would have been running tons of boost and popped the motor.

 

[m4tic]

yes... turbo nibbple - > bottom wga nipple; and then, top wga nipple -> boost control solenoid -> turbo inlet nipple

right now you are only running spring pressure which is ~12psi (poop)

 

[540i to MS6]

Nice. Thanks. I put a vacuum line on and felt the wastegate kick on.

Thanks!

 

[FORZDA 1]

Sounds like the PO bypassed the BC Sol and had the boost line direct to the WGA, which indeed is running off WGA spring pressure. Maybe the OEM BCS is AFU or the PO was just ignorant... Do you have a boost gauge? If not you're setting yourself up for a problem later if you don't know why it was disconnected...

 

[540i to MS6]

I'm going to go ahead and setup a dashhawk datalog. To diagnose this, what parameters should I record?

Right now I have it COBB mapped to Stage 1+. Should I take it back to stock and run a datalog?

I appreciate your help.

 

[FORZDA 1]

I'm going to go ahead and setup a dashhawk datalog. To diagnose this, what parameters should I record?

Right now I have it COBB mapped to Stage 1+. Should I take it back to stock and run a datalog?

I appreciate your help.

Run a log in 3rd or 4th gear, preferrably 4th, of boost/vac, wastegate duty cycle, knock retard, air/fuel ratio, & absolute throttle for a few seconds at cruise, then go WOT up to about 6k rpms, then push in clutch and let the engine idle while you slow down for several seconds.

This will get the basic info down for analysis. Don't change anything yet.