Orlando fuel consumption and power loss

Cylinder pressure fluctuation on a diesel could be a can of worms. Higher fuel consumption and power loss usually point to something affecting the combustion process. Considering the check engine light, did you pull the error code? Without that, you're just guessing. It might not be the crankshaft directly, but it could be a consequential error resulting from another issue. Have you noticed any unusual noises?

Thanks for the reply. I haven't pulled the error code yet, didn't want to go to the mechanic right away. I have had bad experiences in the past. No unusual noises, but the engine seems to be running a bit rougher than usual. Would the error code really tell me if it's something serious like the piston rings or the timing belt? Or is it more likely to be something simpler, like a faulty sensor?

The error code won't pinpoint the exact failed part, but it'll give you a direction. Rough running plus higher fuel consumption does sound like a combustion issue. Given it's a diesel and you're seeing these symptoms, it's best to get it checked by a workshop, they can properly diagnose the problem. It could still be something simple, but ignoring it might cause further damage.

Thanks, I appreciate the advice. Turns out a wire had come loose and the error was something completely unrelated. They fixed it immediately at the shop, didn't even charge me anything.