I have a 2001 xc70 with a weird problem. The first time I start it in the day, the idle is very erratic. After it warms up, it seems to be fine. But, when I am driving, it seems to lunge at certain speeds, like 45 and 80. It accelerates with no problems.

The car has 120k on it.

 

I thought it might be the mass air flow sensor. I unplug it, and then the car will hardly run. Is this normal?

 

Tracy, I was wondering if you had come up with a solution to your problem which sounds a lot like the one I am having with my 2001? I get an uneven idle when the car starts and finally subsides after 30 seconds or so. I also get that surge which seems to come out of the blue and then disappears. I initially thought I might have picked up some bad gas but dry gas did not solve the issue. Fuel filter? Fuel pump? Bad spark plug wire? Lots of things come to mind. My XC70 has 132,000 miles on it and has otherwise been wonderful.

 

Typical symptoms of a worn out throttle body

 

Try the Mass air flow sensor, We had the same issue on our 01 and a new one fixed it. Another issue might be the ETM. We had ours replaced under warranty about 50,000 miles ago, but I am hearing of the new ones failing from time to time

 

I had the exact problem and the Volvo dealer agreed with me that it was a bad ETM, electronic throttle module. They replace it for free under Volvo's extended warranty on the ETM, 200K mile or 10 years. My was a 2001 xc70.

Good luck.

 

Well, everyone that bet on the throttle body was right!! The dealer replaced it on the extended warranty and she's good to go.