do you have a gauge? are you pulling vacuum like you should at idle, and just hitting the wall when it approaches positive pressure?
a week ago I found out the hard way what happens when someone doesn't route the rear 02 safely away from the exhaust,
Fried ECU was replaced with apr stock/91/93/100
k&n filter, eurojet piping and smic, fsi coils, apr r1, apr tip, 3" catted dp to 2.5 straight pipe.
I'm getting no boost I can hear the turbo spooling but have no boost
Checked all pipe connections for boost leaks
I've swapped the apr r1 for a forge no change
pulled the tip and checked the turbo, seems to be normal shaft play and turbo spins freely
pulled the downpipe wastegate appears to be functioning correctly
No CEL's and no faults detected anyone have any ideas on what else could be wrong
How far have you driven it? I'd think a cel would pop up with your problems. Might drive it around a bit just to see if something shows up.
I'd rig up a way to pressure test your intake so you can make sure it holds pressure without the turbo hooked up..
You got a new o2 sensor right?
Yea new bosch 02 sensor, I might be able to rig something up. I can pretty much guarantee it's not a leak soapy water on connections showed nothing. there is no hissing or any sound of air escaping
On my old gti I dealt with some bad aftermarket boost hoses and ended up going back to stock, so I've experienced a 1.8t with boost hoses popping off and leaks
I still haven't been able to do the pressure test, it sucks not having an aircompressor
I pulled the diverter valve out and when the engine is off the valve is closed as soon as the car is started it opens and stays open.
So I have to ask isn't it supposed to be closed until it's pulled open and what controls the opening and closing of the diverter?
it opens when there is vac, closes when there is boost.. its signal should be from the intake manifold after the throttle; its job is to relieve pressure (if any) when your throttle closes so excess pressure buildup dont cause excessive in wear on the turbo bearings.. this should be recirculating back into the airstream post-maf and pre-turbo without leaks.
at idle your DV should be open and your WG closed; the WG should only open as you approach maximum boost.. For stock systems the WG is regulated by the ECU via the N75 valve.
Might check out N75; that can fail and not throw a code.
Just out of curiosity .. have you checked the 3 bolts where the Turbo bolts to exhaust manifold? If loose you can be losing all your pressure there or even the bolts from manifold at the engine.
Gotcha.. well give Hardey or RS Motorsports a call. They might have some ideas on quickest. Maybe a used one laying around or inexpensive new ones... just an idea..