Turbo problem ISX cummins

If you had a coolant leak, I am thinking that the EGR cooler was replaced, not the EGR valve. Anyway do you have a boost gage? If so what is your boost PSI? Turbos are supposed to whistle when they spool up

 

I have never hear of an EGR valve with a coolant leak. No one knows ther truck like the one that drives it. I would keep running it and keep an eye on it. Only thing I can think of is, maybe before they fixed the EGR valve, it was not closing all the way before causing pressure to escape. Or maybe one of the cold air intake hoses had a leak. When they reinstalled them this fixed the leak and the turbo is working more efficiently now

 

would say you have a CM870 with hot side EGR. This EGR valve is cooled by engine coolant and could have been the source of a coolant leak.

The noise you are hearing is likely an exhaust or boost leak. Recheck all connections and clamps for leaks in the area of the previous repair. Something is not lined up right or is leaking. Maybe a soot trail can be seen? Otherwise a pressure test may be in order to track it down.

 

The EGR valve is attached to the exhaust manifold. If it didnt make the noise before the repair it is highly likely that something is leaking in that area or at a connection that was apart during the valve replacment. If it is an exhaust leak a soot trail will form yes.

 

It's common for those years isx to eat turbos.

Thus, the whistling noise. It's going out.

I went through 4 replacements. None of them lasted long.