2007 XC90 3.2l torture device

[rssherwin1]

So how do I start hmmmm. OMG not again I thought I just solved that issue, dang.

Ok now that I got it out of my system here we go.

I have a 2007 Volvo XC90 3.2L FWD with the following codes P0171, P0174, and P1719. I do my own maintenance and am very handy. I have rebuilt transmissions and engines before and worked in body and paint most of my life so I don’t consider auto repair that hard at least the mechanical aspect of it.

Recent (12 months or less) parts that have been changed are as follows: mass air sensor (non oem), pcv valve cover assembly complete (oem), and intake vvt (oem). There are no vacuum leaks that can be found and there are no breaks in intake tubing after the mass air sensor. Also, I have changed the AC compressor, water pump, serpentine belt in the last 24-36 months. The car has about 140k miles on it. My son (18 yr old) is the only one this happens to.

His description is when driving the car it all of a sudden looses power but the engine is still running and then a check engine light. The symptoms go away after the engine has been turned off then back on.

I go get the car, give him my jeep, and the Volvo runs fine no issues at all less the codes.

I changed the vvt last week and it ran fine no codes all week (me driving it) then as soon as he left the house 30 minutes later here we go with car issues. Please help.

Please don’t beat me up to bad for the aftermarket radio it gives him hands free, a backup camera (piece of mind), and monitors the engine.

[wahiddd]

There's a lot that could be wrong here, From Electrical like Harness or connector problems with loose or faulty connections, Fuel System problems like a weak fuel pump which fails to deliver under heavy load or the pressure regulator.
Another area of possible issue is the engine not creating compression in one or more cylinders or potential leaks before the oxygen sensors can affect readings.

[rssherwin1]

I’m not sure if this could help but here are the engine stats (see photo). If there is a trend or an item not in the cluster you would like to see to help eliminate some of the possible problems let me know and I’ll have the radio pull the data for you.

[rssherwin1]

Oh here are my options (see image) for trending etc. Also I just checked and P1719 is not there anymore just the lean bank 1&2 and they are now in red but the car is running as smooth as it was new.

[packetfire]

The simplest possible explanation here is "There's an intake leak - it is intermittent."

The symptoms (loss of power) indicate that it is not a small leak at all.

Something is cracked, or not tightened down, and a bump, vibration, or a left turn rather than a right triggers it. Try to remember what kind of maneuver the car was doing just before it lost power, which might help narrow it down, as the type of motion might be consistent between incidents.

[rssherwin1]

I asked my son to drive it around in the area of our home (short recovery) and to see if he can get it to repeat. I will see if he can give us more information from when it happened.

[chitownV]

Here are some things to double-check when doing your diagnosis. Keep it simple.

I'm guessing you are clearing the codes. Thus, as the DME is setting the long-term fuel trim, it takes time before the code can be triggered again. The emissions readiness system checks are good indicators that these types of parameters have completed their checks in different driving scenarios. This might be why when you son drives the XC90, over time the code finally triggers.

1. The intake does not have VVT. It has cam profile switching (CPS), or like Honda's VTec. This link shows the solenoids in the images, but the labeled intake VVT is the solenoid for CPS https://www.swedespeed.com/threads/p003 ... st-7534805

2. Links to the different codes and what they mean in your Volvo: https://www.dtcdecode.com/Volvo/OBD-II- ... -Reference

3. The P0174 is specific to Bank 2. The first thing I am going to ask is what specific brand PCV did you purchase. Too many stories of someone saying they bought a Vaico one and issues followed. If you purchased an OEM one from FCP and it has FoMoCo stamped on the top, then that's great and just double-check the bolts. If it doesn't have FoMoCo stamped on it, then the PCV would be my first suspect.

4. Along with Bank 2 and the PCV, double-check your oil level isn't too high. (More) Oil could be getting into the PCV and potentially affecting how the internal diaphragm is moving/sealing.

5. Did you change your vacuum pump o-rings/seals? Is any oil leaking from the engine? The P1719 could be oil getting into the TCU connector. If this happens, then it might trigger the transmission into a limp-home mode from a lost engine signal.

6. Lastly, don't forget to review the other maintenance items if you haven't already: https://www.swedespeed.com/threads/the- ... st-7332383

Good luck

[rssherwin1]

Q1)The item in the picture labeled vvt is in fact the part I changed.

Q3) the PCV is a Volvo part from Crest Volvo in Frisco Tx. Regarding all the parts that have been changed the only non-Volvo parts are the injectors (FCPEuro) and the mass air sensor which was purchased at a local automotive parts store (don’t remember where I bought it) All filters etc are Volvo parts also.

Q4) the oil is Mobil one full synthetic 5w30. The oil level is in between the hash marks.

Q5) I changed the vacuum pump o-rings/seals with Volvo parts.

So far the only thing that has appeared is the p0171&p0174 first the 174 then about 10 minutes later on a recheck (without clearing the codes) both 171&174

[chitownV]

What brand is the MAF? Why was it replaced? Why was the CPS solenoid changed? For comparison, both of those are original in mine.

In lower loads, the engine will safely run a little lean for fuel economy. In WOT, the A/F isn’t factored as a tune is fixed. Without knowing, the MAF could be reading incorrectly all the time or just at higher loads and higher rpm’s as the airflow becomes more turbulent.

Maybe you already know the answer, but just wanted to double check and talk it out in case there is anything being missed.

If it were me, I would get an OEM MAF (Denso?) to rule that out since it’s vital to A/F. In FCP, they sometimes don’t have it listed under XC90 and you may have to look under a comparable 2008 V70 3.2. At least FCP has a lifetime warranty.

Like mentioned earlier, triple check the different parts for any air leakage or do a smoke test. Check the exhaust down pipes for any leaks.

Good luck with the troubleshooting

[rssherwin1]

MAF is a Duralast - I must have bought it autozone or advanced auto I think they are the only ones that sell that brand. I had to use the number on the side of it to figure it out. It was changed due to the exact same codes from about 1-2 years ago. I changed the cps (Volvo part) due to the p1719 which cleared up after the part was changed. I still have the original MAF in a box in my shop if I knew how to bench test it I would do so. I will be rechecking for leaks again today and tomorrow. I am thinking of buying a Volvo MAF to verify.