Re: Question about oil viscosity in a diesel genset
Done engs all my life , Blowby is just something diesel engs do mostly due to such high comperssions ...the older thay get the more thay do blowby.
Don't put a multi vis oil into an eng not built for it .
Just use what the eng requires / designed for , doesn't hurt to put heaver oil in like in hot weather , heavy use / like a duty eng running 24/7 , or as it gets high hours on the hobbs .
You can tell if the oil has a lot of fuel in it just by smelling it ( well I can lol) if it's a lot of fuel in the oil you could put a little in a spoon ( go outside) and put a flame to it and it will flash but that would be a lot of blow by , like Sawingknots says piston to cly fit & valve guide fit have a lot to do with it .
Check your valve adjustment and fuel injector timeing & pressure , it all starts with valve guides getting worn , diesels are Very Robust engs and designed with blowby in mind if it starts drinking oil a lot just change more often..
There is no right way to do the wrong thing