Helo, i have 1997 V40 2.0 petrol 103 kw and one big problem. When car is hot sometimes it`s going just on 2 valves. Never when cold, just when hot sometimes from start sometimes during ride. I have new spark plugs.Could it be bad coil ? it has 2 coils one for 2 valves so one of them is maybe bad. Thank for any advice

 

Could very well be a bad coil.

 

Thank, I always thought coil is good or bad nothing betwen

 

Not with Volvo.
They crack and overheat causing misfires.

 

Very interesting, thank You very much. Is it safe to unplug spark plug to determine bad coil? i have heard something about danger for ecu or something....?

 

I wouldn't unplug it.
I would see which cylinder the computer is saying is misfiring.
If you unplug anything unplug one of the injectors.