Sorry I haven't replied in a long time. What had happened to my engine is the following: I used the wrong oil and also used a leak stopper. The engine was plugged up really badly. The low oil pressure was an underlying problem that was not being addresses, so the were no vacuum leaks or TCM problmes...

After spending a few hours cleaning everything and searching in vain for a vacuum leak, I went to a local Volvo specialist and they diagnosed the problem ($95). It is the TCM Throttel Control Module. This seems to be a problem on this model year. It isn't fixed by a novice, either. Once installed, t...

All other advice I am getting is that the throttle body may be in need of thorough cleaning. According to a maintenance release from Volvo through Mitchell, the turbo causes a buildup of carbon in the throttle body and careful thorough cleaning will stop rough idle problems. removal of the throttle ...

I checked the vacuum lines this weekend using carb cleaner; sprayed it along the lines to observe an idle surge caused by vapors. None! So, I called Volvo and they suspect it is the throttle body. I will probably take the car in to Volvo and pay the $100 diagnostic to see if they can narrow it all d...

jblackburn wrote:$1200 for O2 sensors?!

Sounds to me like you've got a vacuum leak. Inspect any vacuum lines you can find for cracking; it's about that time for it to start happening.

Ontario Volvo Dealer: $1200 for two sensors and labor. OUCH! Yes, dad paid for that one.

Great replies so far. Here is the list of stuff I have already checked: * high fuel pressure (Firestone says it is at normal limits) * leaking injectors (I replaced tham all myself with OEM rebuilds) * defective mass air flow (MAF) sensor (Ruled out by Firestone) * oil level too high (Nope, a little...

When decelerating, downshifting, I get a sudden surge from about 500 - 1100 RPM. Foot is on brake (thankfully) and then while in park the idle will stay okay for a minute, then it surges slightly. AC is not on. Major problem is getting costly. I have had this problem for awhile. In 2009 I replaced t...