What is considered excessive blowby in a Dyno?

[in2trux]

(07-31-2018 )Rawze Wrote:  Here is the tipping point that would cause me to start wanting to do something about it. I know the video is kinda red-neck .. the guy just wanted a comparison to another truck so that is what we did to get a sort-of rough idea between the 2 trucks. It is certianly no kind of official type of test in that video, just us playing around...

https://youtu.be/-Og4jCM6Rfg

BTW: that guy had just purchased his truck from loan mountain and had bad overhead cams, turbo issues, and a whole lot more problems he ended up spending thousands on out of his own pocket after weeks of arguing with them, getting nowhere.


This guy later ended up having to de-mandate vs. reman the engine. The extra blo-by it was not turbo related. Sure it still ran, but the thing kept the DPF wet with oil all the time and it would clog up every few thousand miles or so. After the de-mandate, and a few oil changes, it got slightly worse because all the carbon packing around the rings went away.

God bless redneck engineering!
This is on of the simplest and most effective ways to evaluate engine health when considering purchase of a used truck. (quick)