I'm not sure how to check my turbo?
My book says to check if the turbo spins at the intake? This is at the opening at the turbo where the large pipe goes over the top of the valve cover? right? Not the side that goes to the air filter?
I took off the pipe but i can't see or feel the blades of the turbo to assess if it "spins freely on a film of oil". I want to cross this off my list that the turbo is mechanically ok.

Background:
I have a 2001 V70 with recent low power. I cleared three codes
1. engine temp with new thermostat.
2. Catalytic efficiency with 2 x o2 sensors.
3. Cylinder 5 misfire also fixed by o2 change.

There is a stumble after warm up at idle but it doesn’t look like it is due to cylinder 5 misfire. Plugs are very white looks lean but can't find vacuum leaks with propane.
Still no power still no turbo engaging like when I bought it this summer. I will check for cat clog with vacuum gauge soon and or differential pressure at o2 sensors.
The MAF seems like a new candidate, I am running out of ideas...any advice.

 

Take the intake pipe off (accordian looking thing after the mass air meter) on the intake side (compressor) reach your fingers in there and spin the compressor wheel. If it is gritty feeling when you spin it, it's bad. Check for side to side movement or "shaft play" if it moves the bearings are shot and needs a rebuild. Other than that check all vacuum hoses and intercooler hoses for problems. Replace if bad.

 

Thanks, Turbo Matt, Doops…Oh my dog I was dyslectic… the arrow on the mass flow clearly shows the intake pipe. I never had a turbo on any engine before this…can you tell?. So I checked out the intake this time and the turbo spins freely!! With a tiny bit of "shaft play" axial and no blade wobble or grit.
Next, I looked at all the hoses and didn't find any that were cracked, burnt or off. I took the large pipe off (back to the air filter) looking for a crack or anything to account for a lean condition.
So my quest continues for the source of a lean stumble, about every 5 sec, at a warm idle and poor performance.
The plan now is to check the cat for a clog, change the fuel filter and check for an intake leak.
Has anyone tried to MAF with plastic and priming the intake with refrigerant and then air and search for the leak by refrigeration detector alarm hits. I have tried propane and carb cleaner and could not detect an increase in idle or stability change.

If a head temperature sensor was off It would generate a code I assume?
Has anyone been down this road before searching for a vacuum leak or low fuel mixture with some success?

 

Ooops I meant to say :
Has anyone tried to seal off the MAF with plastic and then priming the intake with refrigerant and then pressurizing with airto search for the leak by refrigeration detector alarm hits. I have tried propane and carb cleaner and could not detect an increase in idle or stability change.

 

There is a link on this board where someone made a compressed air type thing to pressurize the system to check for leaks. Some shops use a smoke machine to inject into the system and look for leaks. Do a search for pressurizing intake. You'll find what your looking for. Thats good on the turbo so you can eliminate that possibility. Now you only have about 99 more things to check!

One cheap thing you can check is buy a cheap boost gauge (less than $30 at advanced auto or some place like this) and hook it up. This will verify at least if the car is making any boost. I still do not understand why manufacturers do not put boost gauges on Turbo cars.