MAXXFORCE DT 2012 No Power No Boost Slow Throttle

I have had three trucks and a skid steer come into the shop with low power and throttle response issues in the last couple years that were caused by the operator filling the fuel tank with gasoline. Pop the cap and do a sniff test.

 

Great to hear. Thanks for reporting back on what you found. This greatly helps everyone learn!

 

I am having the same issue on the same year maxxforce currently. My background is also detroit, cummins etc, haven't worked on one of these before. But the symptoms are almost identical, with the exception of a hiss that I'm assuming is a boost leak but I can't seem to locate it. I have ordered a boost leak tester so I will be retesting once I get it. But is also keeps popping off 2 of the small air Lines, 1 at the waste gate and 1 going into the intake.

 

The boost control lines are plastic. Plastic and trucks just doesn't mix well. They turn brittle after a while any it becomes necessary to replace them. These engines are also known for cracking the exhaust manifold near the turbo mount to cause your hiss noise and low boost which leads to low or no power.

 

The rear bolts in the exhaust manifold are prone to breaking as well causing a whistle/hiss noise.

 

Makes sense. Is it common for those boost control solenoids to go bad as well? How would I test that?

 

The solenoids are generally pretty good. The plastic air line that comes from the intake is the supply pressure line to the boost solenoid. With the key off, pressurize this little line with about 23 psi of shop air. This will allow air to pass through to the waste gate actuator on the turbo itself and it should open. Check the rod for travel, it should move about 13mm outward. No air should be leaking out the dump port which goes to the intake elbow. Leave it pressurized and then start and run the engine. With the engine running, the air should be now dumped out of the waste gate actuator, the rod will be retracted.