2006 V50 T5 AWD

I was on the highway this morning, going roughly 70mph, then went to pass a truck and the car started shaking when accelerating gently. I slowed down and it shook more violently at slow speeds. power had been reduced significantly and the car smelled very rich. I drove it home the rest of the way gently where I could get my scan tool. I Pulled the codes: P0300, P0301, P0302, P0304

After some researching i found out the codes were for random misfires, in cylinders 1,2 nd 4. I figured I would replace the sparkplugs this afternoon. took all of an hour and a half. Unfortunately it did not resolve my problem. From looking at other forums it appears it could be any one of my sensors on the engine causing the problem, or possibly bad coil packs.

the car drove just fine yesterday so it seems unlikely all my coilpacks would have gone bad at once. a more likely diagnosis seems to be a sensor but I'm not sure where to start. any ideas?

 

Its possible that the coils failed. I see more of those than anything else. You can also put a block tester on it to see if the head gasket is cracked since that could cause a misfire.

 

Check the fuel pressure. In the 2005+ models the fuel pressure is controlled by varying the voltage to the fuel pump through the fuel pressure sensor, not the traditional fuel pressure regulator.

This thing:

 

Thanks guys,

I took it to a local Indy euro car shop and had them run their Volvo scanner on it. He diagnosed the coils. I got it back and I had 5 brand new Bosch ignition coils overnighted. I should have my car up and running whenever the new coils get in. If it doesn't work I'll order a new fuel rail sensor but I replaced that last year so I doubt it's the case. I'll let you guys know what works. I need to drive to Oklahoma here in a week and then Arkansas right after Christmas. My e30 and my motorcycle aren't practical for that so my fingers are crossed

 

Replaced all the ignition coils, problem solved