What is 6NZ?

I have a 6NZ 475hp and when under a load it pops thru exhaust. It doesn't lose power and put it on computer and it checks out good. Any ideas? Thanks

 

I have a 2003 6NZ 550 hp that sounds like it's sputtering under a load (18 psd. In the 5th over +- 15 rpm). It's usually when I'm pulling a hill. Doesn't lose power but doesn't gain it either. Once I start to level out it goes away and I continue to gain speed and power. Would I have the same problem as Mark2842? Maybe an injector trying to tell me something?

 

Check for a weak cylinder pack mine had one sounded like a slight sputtering when above 1500 rpms on a load. When i inframed motor this spring we found it and no longer does it. But do the simple things first check your injector harness from ecm to the head and then the Plug that goes from outside to inside head then to the injector harness. Wires can get oil soaked and also crack from heat which can create some resistence also wounldn't hurt to look at wiring going to both timing sensors I had lower timimg sensor wire break internally once. I Have gotten into replacing engine wiring when inframing motor. Hope gives some directions in which to look. I have used a old headlight along with a multi meter to load test wires to make sure they are good.

 

Thanks shovel, makes sense. After as many miles I have on it, I guess the wiring harnesses may tend to get a little brittle. Last year I had a harness that wore through and exposed one of the wires. Ran like crap when it grounded out. Cleaned it up and repaired it and it ran fine.

 

Could you expand a little on the use of an old headlight. I think I know that answer but just want to make sure.

Thanks

 

I have a 2001 379 Peterbilt with a Cat C-12 and am looking to replace it with a 6NZ. Can someone tell me the best engine to replace mine with. Preferably something with 550-600 HP

 

well you just sad it yourself. replace it with C-15 6NZ engine and you’ll be set for very long time. believe me I know cuz I have one in my truck. its got 1.5 million miles on it, and those are original miles. did not need overhaul yet. but im planning to do one soon cuz these engines are very well worth it. for durability and longevity CAT C-15 6NZ engine is god of heavy duty

 

Where is the lower timing sensor on a 2WS- Found the top one. is it hidden behind the fuel line coming from the lift pump? Or behind the PS pump?

 

Oh god give me a break.....
There good engines , yes. There not the god of all engines. All the E models cat made and even the Bs are just as good and people got just as many miles out of them too. You can say the same for series 60 Detroit and N 14.

 

Yes its behind the power steering pump. You'll see it as it has wires coming out of it.

Its basicly a crank position sensor.