P0236 and turbo issues, 98 F-vin Chevy

[SchochAuto]

I think I am needing a new turbo, but just wanted to get some verification.

I'll start off by saying I do not have a boost gauge so I can't guarantee anything. I plan on installing one, but it is going to be next week before I can touch the truck because of some family stuff. It is my primary business tow rig, so I need to get this figured out ASAP.

Anyway, truck is a 98 2500 F-vin truck. 250k miles on it but runs awesome. Or did.

I've had the truck for around 8 months now, and for about the last 4 months I have had gray smoke under load and on startup. Not white smoke, truck has new heads and gaskets, but gray smoke. I thought maybe it was the wastegate controller, so I went ahead and installed a Heath Turbomaster, 4" Diamond Eye exhaust, and an HD fan clutch with Duramax fan. Not long after, I noticed some rattling but it wasn't terrible. Well, it all came down to today when I was towing a car body to scrap and I noticed it was down on power and I couldn't hear the turbo spool any more, on the way home it threw a P0236.

I know without a boost gauge I can't be sure, but with 250k miles and the fact that I have the Turbomaster is making me think the turbo is fragged.

What say you folks? And I have a GM-4 turbo now. I am not looking for a massive beast, just a good reliable tow rig that can pull Jeeps on my flatbed trailer easily. Should I go back with the GM-4?

So here's list of new parts:
Fuel solenoid
PMD with relo in bumper
Glow plug controller
Two new batteries
4" exhaust
New crossover
Turbomaster
HD fan clutch
Duramax fan
Cylinder heads and gaskets
Injectors
Water pump
Radiator
Headlights (LOL)

Help me get Big Ugly back on the road!

[john8662]

You need a boost gauge or a bi-directional scan tool to tune a turbomaster.

They ALWAYS require adjustment, the instructions do not get you that close.

PO236 is Turbocharge Boost System. It's a code the computer throws when it's UNABLE to control boost, with it's system, which you disabled when you installed a turbo master.

The computer de-fueled you.

With a scan tool you can read boost pressure off the map sensor (remember your boost is what is measured above atmospheric pressure - usually 13). So 23 psi on a scan tool is 10 psi boost.

J