Low boost with spikes

What year is the engine.

 

Is turbo toasted??

 

Boost pressure sensor?

 

I'm no mechanic. But I would have to question the sensor too. Even his "normal" pressure seems low. I've got an 05 C13 that runs about 35psi. And an 07 C15 that peaks near 40psi. Both are factory as far as I know.

 

I would be looking at 3 or 4 things.

First, is the turbo getting ready to implode.
Time to check the bearings and turbine for play and damage.

If memory serves me, I think this has a VGT. Could be a bad or sticking actuator.

Sensors and wires

CAC and connecting parts for leaks

Last would look for an exhaust manifold leak or cracking around the mount flange

The boost pressure seems low at all times. Makes me think leaks or no turbo rpm

Usually I had 42 lbs at 1500 rpm. Also was set at 550.

 

I am not going to address metallurgy. It's the cracks you cannot see you should be afraid of.

If you have a tired turbo that wont get up and blow... something is wrong. Maybe the whole thing is sick and ready to blow. (Ha....)

IF you cannot feed it air it cannot boost it right? How is the inbound air connections doing on that engine? The clamps etc. Is it a nice tight clear system with good filters to breathe?

Anything else I don't know enough about turbos to really matter here. Those things are so important and vital you have to have a shop or someone who knows what they are doing to really look it over, even if it has to come off the engine and be really looked over.

 

I've blown apart a turbo. It's not good.