Ok, it is my turn to have problems :)
The car: 1998 S90 with 82KMiles. Tonight my wife came home panicking. She just returned home and informed me about the strange behavior of my beloved Volvo. I immediately rushed to see what is wrong. Here are my first observations:

- When starting, the engine surges to about 2000-2200 rpm and then drops to about 1300-1500 rpm. Then it surges again to about 2000 rpm and then settles at about 1200-1400 rpm. Even after settling, it is kind of hunting around, but not as violent as in the first couple of seconds. (Maybe IAC kicks in and evens rpms a little bit?) This happens when the car idles with transmission in "P".

- According to my wife, on couple of occasions the RPMs surged to even higher than 2000 rpm. At that time she got scared and shut down the car.

- On the way home, she occasionaly felt sudden surging when driving.

This all started today. The car had freqeunt oil changes (Mobil 1). Timing belt and serpantine belt were replaced at 68 KMiles. Flame trap and throttle body were cleaned recently. "Check Engine" light is not On. Coolant level is normal. Engine temperature is normal.

Is this what I think it is? My first guess is a blown intake manifold gasket. I checked the FAQ and symptomps do seem similar (uneven idling and hunting). The thing that puzzles me is that it happened so quickly. Yesterday the car was normal, today -- not. If it is not intake manifold gasket, what is it? How can I troubleshoot this? Please help me!!!

Raphael