2012 g37 88k miles

Took this car into the dealership to look into the “check engine” and “service engine soon” light . the service consultant said the Cam position sensor (code p0340) was dirty. Mechanic cleaned and tested the sensor and it was fine. SC indicated there was sludge inside the engine and that’s why the sensor got so dirty. SC said it’s likely because the routine maintenance wasn’t done as needed, which I don’t doubt (not my car). The sc said dealership recommends a new engine. Sc said the car will probably run fine for now, but will eventually get dirty again and act up all over. SC said the dealership doesn’t flush out engines bc it may flush the sludge into other parts and damage the engine. Mentioned other mechanics may flush the engine to get the gunk out but it’s risky.

Drove the car back home and it runs like new! Has anyone here flushed out the engine to clear out gunk? Is that possible on these cars?

 

I used sea foam on a Honda I had that supposedly clears out sludge. You have to do an oil change right after tho. I’d try that before putting a new engine in and take the risk. But, I’m not a mechanic so take it for what it’s worth.