thinking about trading in the gas motor truck for a diesel. i know the afm on the gas motors have issues but i know nothing about the 6.6 diesels, anyone know of what to keep an eye out for? truck has about 150k.

 

not sure what year started the def fluid injection emission...would be nice if that year didn't have it. These systems fail for every manufacturer and are big dollars to fix. When they fail they have a count down timer that limits speed and mileage. if you continue to ignore it, l it limits you to 5mph

Anything with a tuner stay away from; head gasket repairs are 30 hours.

I would have to be towing something incredibly big to buy a diesel. if you don't have the need for it...leave old diesels alone. quote out 8 injectors, a turbo, injection pump and you will see what I mean.
if buying from a dealer...consider a gm warranty package.

 

may i wasnt hoping to hear that from someone especially you. truck looks nice but as you can see in the last two pictures some mods have been done. i dont know what theyre but i see an obdII connection in the center console and im not sure what the gauges and switches are for, maybe airbags? then you have the **** with 1,2 and 3 settings. never seen that

 

DEF systems on light duty diesels started in 2010, so a 2012 SHOULD have the system, but it could’ve been deleted if it’s not in a state that requires emissions testing.

Those pictures - the gauge looks like a boost gauge (I can’t zoom in close enough to see the details) but if those are switches on either side of it, it could also be a gauge for an air suspension system.

The **** on the dash with the 1 2 3 on it is a tuner **** - looks like the controller/monitor is behind the gauge. I don’t know exactly how they work, but you’d select a number depending on what performance you want (may also depend on make - I just don’t know enough about them).

If you get a diesel, stay away from this one - there’s no telling what kind of hack job was done on the wiring to install the tuner or the problems it’s causing.

 

well thats two that say no, so ill pass. thank you guys

 

Like I said, I’d just stay away from this particular truck.

Tech2 was right in that the DEF systems (as well as the SCR - Selective Catalyst Reduction) can be expensive to repair - just today at work (on a 2012 3500 no less) we replaced the pump assembly because the heater had gone bad (there’s a heater in the tank to keep the DEF from freezing and it’s part of the pump assembly) - parts and labor were about $600. But it’s like anything else on a truck - yes, they have their problems, but MOST of the time, it comes down to how well you take care of it.

The newer emissions systems on any diesel (doesn’t matter what - VW beetle to 18 wheeler and everything in between) HATE idle time. The light duty diesels that don’t have a manual control switch for the regeneration burn will only perform a regen during highway speed cruising - if you’re only putting around town, it won’t regen without a scan tool (and even then some aren’t set up that way).

Idling is what allows the particle emissions to clog up the filter, collect on and skew the sensors, and damage related components. If you do a lot of idling, you need to hit the highway for at least an hour once a week to maintain the system.

That said, the only things to be gained by a delete are a cheaper maintenance/repair bill and a check engine light that won’t shut off. Some people will swear up and down that deleting the system netted performance gain, but they’re only seeing what they want to see. The DEF and SCR have no effect on performance or fuel mileage to begin with (when working properly) - their only purpose is to treat the exhaust to meet emissions requirements - so deleting them alone doesn’t net any gains.

Consider your primary reasons for wanting a diesel and then weigh the cost of ownership (stats easily attained on google) against them. Diesels have a higher cost of ownership compared to gas, but they also last a lot longer overall.

 

all this new stuff about them makes me like my cummins in my 91 chevy so much better. yeah the new ones put out 2x (sometimes 3x) as much power but all i need to run that thing is a couple wires one to the starter and one to the fuel shut off. over all i love diesels but with all this high tech crap really kills the fun out of them.