turbo boost

In recent years engine manufacturers have moved away from wastegates and have gone to actuators on VGT turbos. At first they were electric over pneumatic- a separate device had an air supply to it and the ecm would regulate how much air went to the turbo. Now, a lot have simply an electronic actuator attached to the turbo. I suppose it allows for more accurate and faster response and better smoke control.

I just replaced one on an ISX last week. Pretty simple really. 4 bolts, 2 water lines(it is water cooled) and 1 plug. The only thing is you need Insite to calibrate it.I suppose it might work if you just installed it but never tried that.

So the problem now is it can be a mechanical failure with either the actuator or the turbo or an electronic problem with actuator, or obviously other electrical problems.

Now to the OP, if the "truck shop" had Cummins Insite and went through the troubleshooting, they are probably correct. If they just looked up the code and guessed, they could be right or wrong.

reman turbos run between 1500 and 2500 plus diag and labor try to get it
diaged and a estimate there are so many things that can cause a check engine light. the ecm will log the fault the tech will use cummins insite to read the faults they are logged with a time stamp for the first and last occurance in key on engine hours
don't bother with codes that occurred in a time frame that was before your started

we did take it to the truck center and they did hook it up to the computer stuff. they say it's the actuator. we just as you said don't want to throw money away at parts. we don't live in a large community and the last time we had this worked on we did spend a lot and were not sure all of it needed done. That's mostly why we are asking about this on here. They will order the actuator and it's not that costly and can put in on. Just was looking for input as to if others have had this issue. We did repair some leaks and replaced some gaskets earlier in the summer and it was fine then all of a sudden this

I don't hav the exact fault code number but the description for a problem with the actuator should be actuator failed to calibrate. low or n boost can also be caused by leaks in the charge air cooler and low fuel pressure. best solution is to fins a cummins authorized dealer (most new truck dealers) that have access to cummins insite and cummins quickserve online, for the proper troubleshooting steps. this is expensive but it beat guessing and just throwing parts at the problem

about how expensive would you guess for the repair?

the turbo actuator moves a section of the exhaust end of the turbo to increase or decrease boost it is controlled by the engine ecm this from a diesel engine tech with 47 yrs working on cummins engines it is probably the the ex. end of the turbo that is binding and the actuator can not move it usually require a reman turbo that may or may not come with a actuator this is a expensive repai

that is why we are asking questions on here. and yes we understand Turbo is to work all of the time. When we took it to the local truck center they wanted to replace what they called the actuator. but them we spoke with a friend who talked about the waste gate not opening. What I was saying was when it works and we have boost the check engine light will come on. When it is not working and we have no boost the check engine light does not come on. I know they are to work all of the time and it used to. Our friend spoke more about the same thing you are speaking of the waste gate. what can be done to see if that is what is wrong. it really stinks to climb Vail Pass in Colorado with no boost

bph wrote:
we have a 2006 Monaco Windsor with a 400 Cummins ISL. Recently we have experienced issues with our boost. Sometimes it works and when it does we get a check engine light that will flash and go off. When it's to working there no check engine light that flashes. It was taken to the truck center and they said the turbo acuator is intermitanly works, they feel the solution is changing that acuator. Are there any other thoughts on this? Any input on this would be greatly appreciated

Well Sir,
First off, the TURBO is supposed to work ALL THE TIME, not intermittently. That is, it's supposed to be the most helpful when you're on the throttle hard. When just cruising mildly, on flat ground, there's minimal turbo boost. And, I don't understand your statement "When it's TO working, there is no check engine light" What does that mean?

Now, I'm also a bit confused as the term "Turbo actuator". Personnally, I've never heard of that term. There's such a thing called the "Waste gate" that is designed to relieve excess turbo boost so that your engine is not over pressurized because of too much turbo boost.

Maybe that's what you're talking about. Need more clarification for a more accurate answer.
Scott