I have a 1998 V70 GLT (auto) with about 135k miles and recently, it has developed a strange problem.
When cruising at highway speeds and accelerating, all is well. When I lift off the gas and slow down enough for the trans to downshift, it does so rather clumsily. The effect is as if you're driving a 5-speed and put put the clutch down, then release it. Kind of that "humping" sensation (for lack of a better term). It will do this about three times when I lift from about 60 mph. Not sure, but it feels like it's happening between 3-2 shifts; it does not happen right after l lift, I have to be slowing toward 30 or something before it really starts. It also seems to be running rough when sitting at stoplights or cruising around 5 mph.
Also I've noticed that since it's gotten a little colder out, the engine RPMs surge in the morning from about 1000 to 1500 for a few moments before it settles in.
Previous history on this car is unknown, but from the day I bought it about a year and half ago, it's always had a bit of a bang in the 1-2 upshift when accelerating heavily-really kicks the whole car in the ***. I asked the my local Volvo guy about it and he said it was nothing, don't worry.
So my concern is that my wagon is about to need a transmission; would changing the fluid (have no idea if/when it has ever been changed) be rearranging the deck chairs on the Titanic?
I've no upshift arrow on the dash as I understand many other people get with tranny problems.
I also have a perpetual check engine light due to the dumb air pump that I keep avoiding, but when I pulled the codes the other day I also got a P0133--front oxygen sensor. Would that produce the same transmission humping effects I'm experiencing?

Sorry for the long post, and thanks for any information.

 

Anyone?
Bueller?

 

I would try changing out the fluid and see what happens.

 

Thanks, will give that a try and hopefully post back with good results.

 

Front o2 sensor fixed odd downshifting, replacing transmission fluid did NOT fix 1-2 hard shift. However was only a drain & fill meaning that 'bout 1/3 of the fluid was replaced.

Any truth to the idea that a flush will knock something loose and ruin the transmission? I always hear that one and wonder what the heck gets knocked loose? If the system is that fragile, it seems like a few harsh potholes would knock something loose.

 

The new fluid acts as a cleaner.
But if you disconnect the return hose and pump the old out and pour new in you should be fine.

 

Don't worry?! Wha?! From what I was told, the banging is because the fluid is not traveling to where it is supposed to be. This causes the clutch to slip, then if you accelerate hard, it can cause even more severe burning on the disc and possibly bust something. I was warned severely not to ever force it when it clunks like that. Just ease off the brake, let it "clunk" into gear on its own without any throttle, then accelerate out. Otherwise it may worsen the problem.

I am experiencing the same problem, as is most everyone with this car. I am about to replace my valve body, which is what directs the flow of the fluid I guess.

VERY SPECIAL NOTE: The dealer will always just replace a part. They will never fix one. That is what they do because it is more profitable I suppose. This doesn't mean the entire part is junk. Heck, my wife's MAF sensor was faouling up, so I took it apart and discovered the solder connections had all come loose from too much heat. So I just resoldered then and voila!

 

Would you mind elaborating on this process? I need to flush our tranny and have never done it before. It's hard enough finding the apprpriate fluid w/o going broke.

 

You remove the upper tranny cooler line and install a clear hose long enough to reach a jug on the ground. Then put 1 quart of fluid in the system. The start it and watch the hose when you see bubbles in the hose turn the car off and add more. Keep doing that till the fluid coming out looks clean.