Just checked for codes and I have a P0234 overboost. Truck is stock. Should I be able to manually move the waste gate ? I tried moving the lever with a wrench but it seems like it's frozen in place. didn't want to break it. Is this normal? Truck has 43000 mi. on it. Thanks

 

I think all the waste gate does is prevent cold air from entering the engine. but don't force it take to a exhaust shop they be able to set you up. stay away from the dealer unless it is still under warrenty. with 43000 you should still have warranty they are covered to 100,000 on the engine and componants.

 

The dealer now has a great tool to test the wastegate operation. It pressurizes the air inlet system with regulated air and you can run the psi up and watch the wastegate open, or detect leaks at the boots.

 

Or you can do it yourself if you have compressed air. Just remove the line to the wastegate actuator and pressurize it. DO NOT EXCEED 30 PSI.
Too much pressure will blow out the actuator diaphragm.

 

have the dealer check it the 01 autos have a hardline you cant just take ithe rubber off and test it.

 

Thanks for the help. I think I'll play it safe and have a dealer look at it.

 

Picking any dealer isn't always "playing it safe". Try to talk with the tech that does the Cummins work. Hopefully you can get a feel for the guy and see if he can help.

 

Technically, yes and no. LOL

What the Wastegate itself does is releases pressure from the exhaust side. The energy that would be used to speed up the turbo, is bled off through another gate, called the wastegate, this keeps the turbo from having to much speed (turbo wheel speed makes boost).

The Wastegate is actuated from the Cold side of the turbo. A boost line carries the boost from the compressor housing to a diaphram, and the dieaghram has a spring in it, that will move at a certain pressure. About 20PSI. So when the turbo starts producing 20PSI, the boost line carries the boost to the diaghram, which then moves because the air pressure is greater than the spring inside of the diaghram, and inturn, it moves a lever the diaghram is connected to, which opens thw Wastegate,, bleeding off extra exhaust wnergy that would have been used to speed up the turbo even more.


In MB's case, the Pressure is being applied to the diaghram, but it might be stuck, or the wastegate arm might be stuck, and is causing the turbo to have too much speed, and make too much boost for what the factory computer is set for. That's where your code came from.

The computer see's too much boost and says "Whoa, somethings wrong, lets tell the driver" and it sets a code with a light.

Now, your job is too see,,, is it really a malfunctioned wastegate? or is it a bad MAP sensor? Or, Did you work on the truck, and happen to unplug it? or did you just wash the motor causing a flaky electrical connection while it was drying?

Lots of possobilities,, usually one answer.

Merrick

Edited for grammer.