Weird transmission issue
 

Hi, recently bought a 2005 AWD S80 2.5T with 80k miles. Dealer had the transmission flashed before I bought it. Drove great at first, no problems, but if I took a decent bump or pothole it would shift weird until the car was shut off for more than a few minutes.

Brought it to the local Volvo dealership, they recommended and performed a transmission fluid flush, and afterwards when they drove it it was shifting hard. When I picked it up it had NO problems whatsoever. Drove like new.

Last few days it seemed almost like the fuel pump sputtered (VERY intermittent -- happened twice, for a few seconds) since RPMs dropped and engine definitely slowed. I want to say the idle is a little weak but haven't had problems, just seen lights dim and felt a VERY light shudder when sitting idle for a few minutes. Now last night after driving for a while (a good 30-40 minutes) it would take the shift into 3rd or 4th really hard, RPMs going up and "kicking". Start it this morning, no problem. Once it's warmed, and I shift a few times (parked and backed out), a light kick from reverse to drive and same issue with upshift to 3rd/4th.

Park it, drive again 15 minutes later, put a good 10 minutes in, no issues. Very slight kick when I go direct from reverse to drive, but nothing if I hold it in neutral a few seconds.

I've read sometimes the MAF can screw with the shifting -- I only know enough about cars to do basic home maintenance, so I have no idea if this would be the effect -- but the problem is intermittent, and even then only when the fluid is hot. No codes or anything, or obvious noises beyond the kick when it does do a rough shift. Dropping it off again now, but the last time I asked they said to opt for a new transmission since they had no idea why and didn't believe me when I said it was shifting fine when I picked it up!

Any ideas? Love the car, so I want to do what I can!

If it is a dirty MAF, the issue likely won't show up until the car is warmed up - at that point it has trouble calculating fuel/air and may take some guesses at when to shift.
A can of MAF cleaner spray is about 6$ and that could possibly be a lifetime supply. 2 torx holding it in - take it out, spray it clean - let it dry (dries fast) and put it back. If nothing else, do it as maintenance and to rule out that as an issue. If it has actually gone bad you would be more likely to see an MAF related code.

Last few days it seemed almost like the fuel pump sputtered (VERY intermittent -- happened twice, for a few seconds) since RPMs dropped and engine definitely slowed. I want to say the idle is a little weak but haven't had problems, just seen lights dim and felt a VERY light shudder when sitting idle for a few minutes.


i bet this is the a/c compressor coming on it will dim the lights and the idle will be pulled down by the increased load on the engine. the lights dim from the electrical load the fan and the a/c compressor clutch. just a thought. i tried to do the quote thing i don't think it worked