1mil. mile 07 volvo vnl670 over haul

i would run it till it tells you its ready for a in-frame. run regular oil samples. and keep a eye on things, and keep money put away for it but i don't see any reason to do a in-frame as a preventative measure.

 

I would do the bearings.

 

Symptoms of an needing an over haul: Rod through the block. Any questions? I'd just keep running it till something happens. You can do oil analysis and look for unusual things. Wait for something, excessive oil use, loss of power, or using coolant. I think those are the normal things. I can tell what a tired Series 60 looks like when someone starts one up or accelerates, you get plenty of gray/blue smoke, classic sign of a worn engine but it still runs great. Not sure what to look for on an ISX, you're lucky you made it to a million miles. Have you seen what past maintenance work was done to it?

 

Is not the miles on the engine, it's all about the fuel it consumed, that what wearing out the engine not the miles. if you had two engines one run at 700 rpm and the other running at 1,500 rpm for three years, which engine would have the most wear. ?

 

Black smoke could mean a simple boost leak.

As already mentioned, run the truck until you notice something unusual.. Like consuming things its not supposed to, or extremely bad mpg. Also the obvious vibrations and or noise.