Strap in, guys, New user here and this might be a long one. I hope this post is okay, and I hate to be the guy who signs up just to ask a question, but my hopes are that someone here can not resist a mystery and might have that one answer that I am missing.
About a week ago I picked up a used 2004 Volvo XC90 T6 with 116k miles. Between Carfax and hard copies, I have service records going back to 2008, and by all accounts, this vehicle has been meticulously maintained. There have been some issues, but the work had always been done to fix them by the dealership, including a new radiator, water pump, thermostat, timing belt with new idlers, throttle body, Mass airflow sensor, spark plugs, fuel filters, fuel pump, brake pressure switch, and brake vacuum pump pressure switch.
Routine servicing has been kept up on, regular maintenance kept up on and so on. There was a stalling issue before I purchased it that the dealership had thought was remedied, but come to find out, they have been chasing this issue for a while now, at least since September of 2021.
The issue I am having is still intermittent stalling. Everything else seems just fine to me, and the vehicle started right back up both times with no issues and made it home. No signs of trouble before stalling out, at least not that I could detect. No check engine lights, no sputtering, it was as though the vehicle was just shut off while going down the road. The only lights I have (or messages) are for the parking sensors needing serviced, and for the Anti Skid system that is just a sensor needing replaced in the steering wheel. The only code I can pull with my scanner is an EVAP system leak (small leak) that is most likely from a worn out gas cap seal that is cracked.
The dealership's service tech has not been able to figure it out and has installed a new MAF sensor among other things with so far little luck. The problem seem less severe than it was before I purchased the vehicle, as the previous owner had issues with it stalling more often, and then running really rough before dying again. At this point, I can drive it, sometimes for a couple days without a hiccup and then seemingly at random it will just die on me, both times while at a stop or slow speeds in traffic.
While idle, my RPMs seem to hover between 600 and 400, and higher upon first starting the vehicle before they drop down. I have checked my alternator with my charging system scanner, and all indications say it is good with the correct voltage, I fully charged my battery to make sure that was not an issue as well (before testing the alternator)
One thing I found after looking around online was a guy who mentioned that his turbo intake hose near the radiator was partially melted on the underside, so I checked mine and it was pretty sticky like it might have melted a little bit. The other thing mentioned is a crack in the plastic turbo housing tubes that I can not find any damage on, not without removing them anyhow.
Below are scanned copies of the various service records if anyone wants to take a look, and possible narrow down the possibilities. The service tech at the dealership has basically given up and told me in so many words he does not know and has no idea what to do. If i can get this stalling issue resolved, this would be a fantastic vehicle.
