Looking to potentially buy this truck, it would be my first diesel. He showed this video to me, unsure of "how bad" the blowby is. Does this mean a rebuild could be required in the next few thousand miles, could it live like this for another 100k?

Any info is appreciated, thank you.

 

Well it does still retain the OBOD and at least has aftermarket downpipe. Sounds like any used 7.3 I have heard.

Is it stock? Will it make full power pulls to redline?

 

Blow by ain't bad, normally when bad it tries to lift the oil cap.
And these engines even with a very low compression hole will run for a very long time.

 

Can't say it's any worse than mine. Some people use a ping pong ball since it'll sit in that hole a little bit.

That orange boot needs to go! Mine disintegrated upon removal..

 

The "blow by test" looks good from where I am sitting. I would have no concerns pertaining to that part of the truck. The engine sounds like a healthy 7.3L at idle as well simply based on the 25 seconds of the video. These engines are really quite tough and will run a very long time as long as they were maintained well.

Some people use a ping pong ball as this YouTuber has in the video I snipped an image from.



Image source: 6:00 into a video by Living On Wheels called "Ford 7.3 Powerstroke how to REALLY check for blowby on a diesel.

As the YouTuber goes on to describe, the ping pong ball is a good method because it stays in place quite well and is very light. So, if there is any blow by at all to be concerned about, the ball will show that. A cap rattling off such as in the video you posted would not concern me at all.

In the video below, the YouTuber compares a ping pong ball to the oil fill cap on his truck during the same run cycle of his engine.


As you probably saw, the oil cap rattles off in a similar fashion as it does in the video you posted. Your video may actually show a bit less "floating" of the oil cap. What you are really looking for (and hoping not to see) is the cap to actually pop off of the oil fill neck as this fella describes a bit in his video.


This is not a 7.3L PSD, but at 2:38 you can see the oil cap trying to literally blow off the oil fill neck. This is bad and not what you want to see in a potential purchase truck.