New to volvo's jsut using my uncles for the summer. Gonna give you guys the best description i can.

The car is a 2000 v70 base, and its manual. I got a solid, non-flashing "check engline" light on the freeway and drove a couple miles with no problem. When i started my car the next time the the rpms at idle in neutral would jump up to 1200 and bounce back down to 500, but the car was driveable and wouldnt stall. I turned the car off, let it sit, and the problem would magically be gone. My check engine light magically turned off too so i thought i was good.

Now, today my cars RPMS started fluctuating all over the place, no check engine light, and it got so severe that rpms would reach 150-200 and would stall. I had to turn the car on, put in first, floor the gas and get a couple feet of forward movement before the car would die again. did this like ten times til i luckily made it to a parking lot and chilled for 20 mins in downtown LA (almost got shot/approached by multiple gangmembers haha). turned the car back up and MAGIC the problem is gone. idle is normal. I just drove back home and want to fix the problem before it haunts me at a bad time like on the freeway or worse, a bad neighbor. car has 75,000 miles, new oil used 10w40, uncle says there's new fluids throughout the car. wtf do you guys think this is