How bad are the early paccar engines?

Yes, PX8 is a Cummins.

 

Paccar,Cummins, Detroit Volvo,mack. All Trucks have there problem.some people Prefer this engine.some people prefer that engine.it just the luck of the draw.

 

Late to the party but I have a 2009 paccar px8 with almost 800k on it and 21480 engine hours. It is just a Cummins 8.3 and they are good little motors. I have a 330 / 1000ftlbs and haul at an average weight of 38k lbs with a 10 speed Eaton. Hasn't need much of anything aside from general maintenance. I am getting ready to do a in frame as she's starting to get some blow by and has a mysterious oil leak in the driver side of the engine block. I'd buy 5 more of these trucks with the px8 if I wanted.

But yeah the px8 or the newer px9 are just the ISC while the px7 is the isb 6.7

 

Did you pull oil samples regularly? Reason I’m asking, I have a PX8 with 530k on it that showed normal levels on every oil sample up until the last. The aluminum levels jumped drastically. It was sourced as possible piston skirts. Just curious if I’m looking at an in frame at 530k miles and 13850 engine hours.

 

No I haven't. Bought the truck with 717k on it and I litteraly just did an inframe here over Thanksgiving. The engine showed very little wear cylinder wise and was still holding great compression. Had a little bit of blowby but nothing wild. Did the rebuild right at 798k miles an 21890 hours. Only major wear was the connecting rods at the crank tolerances we're getting lose. So we went with new rods as well. Now have 5k miles more on the rebuild with no issues.

Parts and labor ran me right at 16450 including the rods and a new injector that broke in the rear down. Turbo has a out 310k miles on it and doesn't show any major issues either

 

Well, if you happen to see this, I’m 99% sure the lab sent me the wrong sample results. Cut my service interval in half and pulled another sample. It came back perfect. Drove the truck 841k before an in frame. Reworked my head and was able to keep the crank. Went back with OEM parts and got a 12 months unlimited mileage warranty. Cut them a check for $17130. I plan on at least another 500k before getting out of it. It’s not a powerhouse but I like the little engine.

 

Glad you got a lot of miles out of it! I'm still driving mine and now sitting at 1,045,000 miles and 34,000 hours. Going to do an ISL swap at the end of the year though. She's got a pretty big crack on the front structure gear housing and the labor to fix that is about the same as an engine swap. Got a good deal on a 2018 ISL 400hp with full Jake brakes out of a firetruck that was wrecked. Just need to swap over a few parts and it will be a runner. Will have to do some "down grades" but I think it will be a good swap for my aging motor. Besides the crack that has been JB welded as a temp fix, she's leaking oil everywhere. Seaping out of the the top of the valve body, oil cooler, and burns oil after excessive idle. I work this engine hard as the truck now grosses about 50k lbs daily and it's just starting to show some age. Over all it's been great motor. Only expensive but about it is just about everything that hangs off the motor has been replaced due to age and failures. Fuel system, turbo, air compressor, high and low pressure pumps and so on. I'll probably keep this engine as a spare or a party engine for any random fun projects in the future.