High fuel consumption

I have a 2011 6cyl with 1.2K's, Yes 1,200,000 kilometers. about 100,000 kilometers ago I had the swirl valves changed. Prior to this the engine ran fine until the swirl linkage broke. After replacement the engine still runs great. Except I now have a smell of fuel in the oil, the resonator off the turbo seems to have more than usual oil in it and the engine is using 30% more fuel. Any thoughts on if this may be related to the new swirl valve maybe not timed correct or something off. Thanks
ps I know it has nothing to do with the 1.2K's

thanks in advance for all the input

Who did the manifold replacement?

Not sure how fuel getting to oil, but something is leaking that was not leaking before.

Injector leak lines damaged?

Did you have this since new and put on all of those kms yourself? Many here would be interested in what all you have had to fix over the years, what kind of driving, and what maintenance schedule you followed

Maybe the solution lies outside the box, simply call MB and tell them they can have yours as a monument to their reliability, and they will give you a new one :

It's pretty easy to damage the plastic leak line connectors when installing the rubber cylinder head covers, especially if they are brittle due to age. If there is a leak it should be obvious if you pull the covers. But that doesn't explain fuel smell in the oil. If you have something like a stuck injector you will want to get that diagnosed as quickly as possible as it can lead to a damaged piston, and you certainly don't want to harm an engine that young.

The only way I know of for fuel to get in the oil is from an injector leaking at the tip - a condition that will not often set a code. I think it would be well worth it to protect your investment by removing and bench testing all injectors at a bosch facility. It is not worth it to gamble with a $12,000 engine - I would immediately lock out and tag out the vehicle, and change the oil if you need to run the engine for further diagnostics. If you remove the injectors yourself, remember this must only be done with a HOT engine, very carefully so as not to break the hold down bolt threads. Then the copper injector seal and the hold down bolt must be replaced every time it is loosened.

That being said I don't know much about NVC3's. Is there some system where the fuel and oil are separated by an o ring or seal?

I didn't think we could remove and replace injectors because Mother MB has to reprogram them. Thanks

Well unfortunately I don't have a magic solution. It's all highway, vehicle travels approximately 700K a day. Oil changes every 16K and EGR cleaned at every oil change. Had to replace the DPF at 750K, and glow plugs every 150K. Overall it's been a very reliable and efficient vehicle except for the fact I don't have a reliable MB dealer close by. I realized the problem with Sprinter is MB themselves. Sprinter should be division of it's own so you don't feel like an outsider sitting beside someone waiting on a washer fluid top up on their AMG. Sorry for going off a little.