V70R P0101 MAF Mystery (blown head gasket) Topic is solved

[V70r carbon]

Has anyone else besides me jumped through hoops trying to get rid of a P0101 ( low mass airflow ) engine code on a P2 V70R? I changed the plugs, coils, and the MAF sensor. I did the rubber glove test on the oil filler to see if the PCV was blocked and the glove wanted to suck into the engine. When I went to adjust the waste gate, I noticed that the rod would not move until I gave it at least 7 psi and then it moved in jerks and spurts. ( factory is 4.4 psi) .
Does anyone know where to buy a new one besides Volvo since theirs costs $2,000 and comes attached to a turbo unfortunately. Another thing, could my parts guy mistakenly sold me a MAF for a low pressure turbo if there's a difference? Anyone got any ideas? Thanks.

[mrbrian200]

Has anyone else besides me jumped through hoops trying to get rid of a P0101 ( low mass airflow ) engine code on a P2 V70R? Thanks.

Yes. On mine it was the throttle body (Bosch type throttle body on my '06 2.5T same as your '05 R). Internal nylon gears wore down and were binding making the throttle plate stick at 7% and 15% sometimes. If you pressed the pedal down past about 40-50% the stepper motor would overcome the resistance at which point the car would sort of launch. You'll need a VIDA or an OBDII tool with live data to diagnose this as a potential problem. I was also getting occasional DTCs for fuel trim rich and lean (sometimes it didn't close fully to idle stop either), but the low MAF DTC was consistent.

Note on mine it didn't appear to be sticking during the key on/engine off sweep test. You have to drive the car and watch live data to see how it acts. Graphic display with a VIDA-DICE with accelerator pedal position/torque request and throttle plate position parameters displayed would be preferable over trying to watch numbers.

[V70r carbon]

Thanks mrbrian200. I'm going to look into your advice as a next step since Swedespeed hooked me up with a contact where I can find a wastegate replacement since it's still sticking. If that doesn't work, I'm cutting off the catalytic to see if its blocked or restricted and re-welding it if it's ok. I'm still wondering if the MAF that I replaced is the cause and if the "R" MAF isn't the same as a regular 2.5.
Again, thanks for the help.

[mrbrian200]

I'm still wondering if the MAF that I replaced is the cause and if the "R" MAF isn't the same as a regular 2.5.
Again, thanks for the help.

The MAF P/N is different between the R and the 2.5. The sensor hardware is the same the internal SOC uses different calibration data.

[abscate]

Erie Vovo in NY probably can get you a wastegate from a used car.

Try putting part number into eBay, too?

[V70r carbon]

I'm still wondering if the MAF that I replaced is the cause and if the "R" MAF isn't the same as a regular 2.5.
Again, thanks for the help.

The MAF P/N is different between the R and the 2.5. The sensor hardware is the same the internal SOC uses different calibration data.

Thanks for the reply, appreciate it.
It's now September and I believe that after changing all the coils, injectors, factory plugs, MAF sensor, complete PCV system change, thermostat and alternator, I found that the ground strap from the engine to the chassis connector was completely corroded and had fallen off. ( passenger side ) The strap was still good and the frame is rust free but the connector to the frame had rotted out. After changing the connector last Sunday, I havent had a PO101 engine code, coil or injector codes, the cold starts are normal and there's no longer a stumble between 1500 and 2500 RPM's under load or parked. YEE-HAW!!! I hope that this can help. However, when all the engine codes started, I also lost my AWD, ABS and the "Advanced" shock setting button always stays lit but it's amber and I can feel the difference when switching settings. I was wondering if the bad ground could have damaged the AWD module?
Thanks.

[V70r carbon]

UPDATE: After 3 starts, the check engine light lit up and the hell started all over again, except now I was slowly losing coolant. I changed the reservoir cap since I couldn't find any leaks and there was no steam coming out of the exhaust. ( the oil cap and oil on the dipstick looked good ) The same P0101 code, various injector codes, misfire codes came back again until yesterday that I smoked out traffic with my tailpipes. The low coolant light went on along with a low oil, stop engine light warning and when I pulled over, the oil level was way over the max level and the oil was cloudy. ( Low oil level warning.. weird ) Head gasket let go in a big way, but what I'm thinking is that before it blew completely out, it was just leaking enough to throw out all the codes that I was getting. Any thoughts on this? I'm pulling the head tomorrow and it's costing me $1,300 for the gasket kit, bolts, water pump kit, and timing belt kit, besides sending out the head to get planed and changing the valve seals and flushing the engine. I hope sharing this can help anyone out there and would appreciate if anyone could tell me if the B5254 T4 (R engine) is prone to head gasket failure.
Thank.

[abscate]

I would guess with 85% confidence the two failures are not related.

Don't forget to evaluate the oil cooler as a possible source of oil/coolant contamination, too, although the steam and smoke tells you head gasket is definitely gone.

It's worth fixing...well done and good luck on head job!

[V70r carbon]

Problem solved. The head gasket between cylinders #4 and #5 was leaking just enough to send me into the MAF, injector and coil codes for the longest time until it finally blew out in a smoke show. VIDA or Snap-On OBD scans never offered the possibility that the head gasket was shot. I really wished that it happened sooner because after sending the head out to be rebuilt and the engine was running fine, I put back the original MAF, the original ignition coils and injectors to see what would happen. Ive put 15k on the engine since and still have a mess of new parts as spares that I never needed.