MBN to 6NZ Help

Hi Don: Cant answer your ecm questions(Mr. Haneys territory) but is your buddy's 15.8 a complete engine or just ecm?

 

The 6NZ will drop in place without any trouble.

The 3406E engines may or may not depending on engine serial numbers. For these to work the 3406E 14.6L must have an engine serial number prefix 2WS. The 3406E 15.8L must have a serial number prefix that starts with 1MM. If either of them fit the serial number prefix requirements, then they'll drop in place with no modifications.

With all three engines you'll have to set Customer Parameters in the ECM to match your MBN engines ECM.

 

The valve at the filter base will stay with the MBN, do not transfer it to the 6NZ. The 6NZ will not have this valve and the wastegate on the turbo work like the earlier 3406E. Do not transfer these parts.

The only thing you'll have to transfer is motor mounts, the alternator and A/C compressor mounting brackets from one engine to the other. These parts can be specific to the brand of truck they come from. These two engines are identical as far as the block and heads are concerned. The front structure and flywheel housings are the same. The only differences on the exterior of the engine are the things that would be different from one truck manufacturer to another. The plug and wiring from the cab to the ECM will be the same.

The MBN ECM will not work properly on the 6NZ, because of the boost controller/solenoid valve at the filter base. You can flash it to a 6NZ, 7CZ or PDI file work properly though.

I don't understand why you'd want to do all this work to get rid of the MBN. Does the MBN need a rebuild? You can convert your with programming the ECM

You can flash your existing MBN ECM to a 6NZ, 7CZ or PDI tune to get it to run correctly. The internal differences between these engines is pistons, camshaft and injectors. The other major difference is the ECM programming, the ECM's are the same between them. I'd leave the MBN in the truck and modify it, before I'd go through the expense of buying a 6NZ and exchanging motors. I've done a number of these for people with great results. Then wait to do the internal changes during a rebuild.

 

You just need to look at it yourself and figure if you rebuild yours it would have 0 miles on it and you also would not have to worry about quility of build and you could also do it how you want with yours as in any ceramic coating you would want done or if you wanted the motor balanced or any of those things. Then once its rebuilt your way have the ECM sent out to Mr. Haney or whoever you want and have it reprogrammed for a 6NZ and get the power and mileage you want out of it. Might cost a little bit more but you will have the assurance of the motor having a fresh build and it being done the way you want with those little things done that the others dont come with.

 

Great logic here, imho. Also, your engine isn't showing any sign of problems on the horizon = boost good, oil samples good, oil pressure good. Why not let Mr. Haney take a shot at your ecm, (Mr. Haney I need to talk to you too) and run it a while longer, then take the money you save on fuel and save it for an inframe when it's time? PP is even advertising an ecm flash for the MBN that is supposed to net .8-1.0 mpg improvement.

Mike
P.S. I'm in a similar situation. Just traded in my T800H (3406E 5EK)on a T600. It had 1.1 million since overhaul, oil samples, pressure, etc were good. I decided it was time to get something more aerodynamic, plus going from a 50" modular sleeper to a 72" acad with the studio option is a nice upgrade.

 

I wouldn't rebuilt it until it needs it. Head gasket failure, cracked head, overheats and scores a liner, excessive oil consumption......... something that would make you take the head off would be when it got rebuilt. I've talked with guys with 1.3 million miles without a rebuild yet. Run it till something makes you decide to rebuild it.

The 6NZ with 250K for $6200 isn't a bad price, but not a great price either. Does he have all the reciepts for the rebuild? The $8K to pay for it and labor to do the swap should be enough, depending on the hourly shop rate.