2007 xc 70. Late last summer a problem started that once the car warmed up, at about 1500 rpm to 2000 rpm, in any gear, cruise control or not, the car would feel like it's missing big time. Tach hunts wildly back and forth between 1500 and 2000 to 2500 rpm. Replaced coils, misc turbo switches, throttle body...nothing is working. Prefer not to have to spend $1200 on a new ECU. It's definitely temperature related, as I can drive it at 15 degrees F without the problem occurring. Much above that, after the car warms up, it's like riding a bucking bronco.

Is there some master temp sensor the ECU uses that I can cut out of the system (pack with ice, lo?). I've had it in the hands of several veteran Volvo techs; no one can figure it out.

Can anyone hear help?

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I do not own a car represented in this forum so I don't check here. I just saw this post.

How'd you make out? I could only guess you have a bad coolant sensor and possibly a bad vacuum leak.

 

I gave up! It started doing it cold or hot...my wife wasn't about ready to let me spend another $1000 on a new ECU or anything else for that matter.

But she was pro-active and found a sweet used 2007 XC 70 for $5k! I donated the old girl to charity.

 

But now you have me thinking. How would a bad vacuum leak affect the acceleration of the car?

 

say the vacuum leak was from the line to the boost controller.. no vacuum, no boost, no power...