Turbo/induction troubleshooting 2006 XC70

[saq]

Have a 2006 XC70 with the low pressure turbo engine. Car recently has started working OK up until the throttle is about 1/4-1/3 open and then it is worse than the '82 240 92-horse wonder ever was - we're talking 25 or so up even minor hills (will do 40 fine on level). Car starts and idles great, so doesn't feel like a vacuum leak or lack of compression in one or more cylinders. Haven't checked ECT sensor, can't find specs for it but no black smoke (if it is the same as what drives the temperature gauge then it should be close enough to be fine, I know on LH2 it's separate) Disconnecting MAF leads to rough idle, so seems like that is at least somewhat working.
I don't hear or feel the turbo spool up ever. This makes me suspect the turbo control valve or the turbo unit itself, but I'm not sure how to test beyond continuity (within range, high 20 ohms). Can you safely try putting 12V across it at idle and listen for the turbo to spool up?
I even tried borrowing one of those code reader things that works with your phone from my dad, and it was about as helpful as I figured it would be (nil) - evidently the cat is marginal and that was all it says. Wouldn't surprise me if that may have to do with induction issue as it seems to be running rich.

So far possibles as I see it - Turbo control valve, Turbocharger, ECT, or electronic throttle module failure. Not sure where to go from here as what I have for instructions is 240/740 stuff, Bosch Fuel Injection guide (doesn't do ME7), and a VADIS which doesn't really go into troubleshooting much. Where to go from here? Where did you learn all of your new Volvo functioning and troubleshooting specifics?

[jonesg]

a code reader for your phone will indicate turbo boost pressure.
Vida can monitor several parameters.
could be many things.
Clogged cat, stuck turbo, turbo sensors, clogged intercooler or charge air pipe leak at the turbo.
But it should be setting a code of some type.
CEL?

[Vova585]

Totally agree with Jonesg. It could be many things. How quickly you need this car fixed and what is your budget would be my first question. If you need car- yesterday, and money are tight-better send to professionals to diagnose and take from there. Please avoid "parts cannon" aproach since it will get way more expensive than diag cost.
You can check the basics like suggested by the Jonesg. Remove the turbo air pipe and see if the cartridge is still spinning or stuck, check if waste gate is not stuck open(remove clip from the rod and manually check if able to open close freely. Check if upon start waste gait is not commanded to be open. If you have a cheap salvage yard need by, you can sure try boost pressure sensor, boost control valve, manifold pressure sensor...however only if they sell for cheap(those are not too expensive even new, so for 120 you probably can have them from fcp, dont quote me on that).
Plus if you plan to keep this beast, invest $100 into vida/dice clone and it will make your life better in a long run.

[Blacklab467]

I would first check the very obvious and simple things, starting with the intercooler piping connections. That house can be damaged by oil and deteriorates. I had one blow off after I did the PCV job and it resulted in the symptoms you describe.

[abscate]

You can’t put 12 volts on the turbo solenoid to test it, it’s a pulse width modulated solenoid regulating pressure in a defined way, not an on-off switch. You cannot test it revving at idle either, it’s more sophisticated than that. It commands torque from measured load, not rpm.

It’s get 12 volts direct from the fuse buss, and is operating by grounding at A38 in a complex waveform

[saq]

Looking at this again. Reset the CEL, thinking that it might pick up whatever is wrong on the next trip but it has stayed happily off while the engine is definitely not working right.
I have been looking at the other control elements - the red hose is supposed to provide pressure when the engine is running to activate the turbo on the yellow line, right? I tried swapping the red pressure line and the blue return line to see if I could get the turbo "always on" but it didn't work, and I pulled the red line to see if I had pressure and there was no air. The yellow line seems to have no leaks, not as sure about the red - I can blow air through it but not sure if that is the usual "engine off" status.

Is the solenoid driven at all at idle? I can throw a scope on the plug and see if I get pulses if it is.

[saq]

I completely removed the rubber sections of the induction and the over-the-block plastic runner to inspect. The rubber hoses are disgusting, I have never had a car as filthy as this one with oil going everywhere, but never had a turbo before either.
Anyway, there are no cracks, and while it has blown off in the past when it did I snugged it up an extra half inch on the plastic pipe and cranked it down and it has stayed on since.
Actual question - with no cracks or holes there would be no hose issues, right? Just softer than usual rubber won't cause this problem, right?

[saq]

Does the vacuum gauge on the inlet manifold to check for clogged exhaust work on the turbos?

[jonesg]

reading your first post again, theres nothing to indicate any problems with the turbo but guessing.
I can't hear my turbo either but I know it gives boost by using a $12 ELM 327 on my phone.
I would want to read fuel pressure under load too.

[saq]

I'm wondering about the exhaust now and trying to get enough of it off to see. It is doing the bad fuel economy and bad performance, but more of a rich smell than rotten eggs. I've never had a Volvo coke up the exhaust before, but then again I've never had one that eats as much oil as this one (1/2-2/3 of a quart per 1000 miles - I've been suspicious of the PCV, but it doesn't puff up saran wrap placed over the oil fill...). Sprayed the O2 sensor with lube to see if I can get it off and try the "see how it runs with the O2 removed to give an outlet" hack.
Makes sense that if there is a restriction on the exhaust flow the turbo wouldn't turn much and the compressor would not be working.