High egt cat 2ws

Exhaust will easily get over 1000-1200 loaded
850-950 on flat ground with empty cow trailer and wind.
Background
Have owned this truck since new
2016 389 Peterbilt
Cummins ISX was replaced with a 2ws (set at 550-600 horse, 80mm non wastegated turbo) caterpillar engine at 600k miles
2ws had a complete platinum overhaul. Cat engine currently has 400k on it since then. Recently had a turbo come apart (broken shaft, shrapnel everywhere) .
We replaced turbo, cac, and air filters. We thouroghly cleaned all intake and cac piping.

Truck is now running high egt!
We have tried 2 different turbos
We have tried 2 different cac
We have tried 3 different ecm
New exhaust temp probe
Wire from probe to gauge
And tried different gauge.
We have inspected and reinspected exhaust for obstructions and pressure tested intake for boost leaks.
Truck seems sluggish with only 28 psi boost
Truck used to run well with 33-34 psi boost
Again have inspected an reinspected for boost leaks
I own the truck but do not drive this truck much so I do not know for sure if it ran this hot before the turbo failed. Although had a very particular driver in it that would have definitely mentioned the heat!

 

@wore out is the man for you!

 

You say turbo was replaced,. Are you 100% certain you have no exhaust leaks before, or at the turbo flange? Cracked manifold? Guys are bad about not replacing flange nuts/bolts/studs, and getting leaks there.

What is left of the DPF?
What about smoke during acceleration, whistling noise?

 

What exhaust housing is on the new turbo vs. the old turbo?
I ask this because out of the box most 80mm that you get have a 1.58 exhaust housing on them which will be too big for what you say the engine is set at.
Most guys at 550-600hp run a 78mm turbo with a 1.45 exhaust housing. there are some that are fine with running a 80 at that power level but they typically run a 1.32 or 1.45 exhaust housing on it instead of the 1.58.

 

It’s an air problem. M gonna say something dumb but seen it lately are the air filters in it upside down?

 

Bully dog manifold no cracks no leaks. 1.32 exhaust housing.
air filters are installed correctly I even pulled air filters out and test drove no difference
Truck has a little 18” muffler and straight through exhaust. Truck does smoke a bit building boost but it clears up at full boost
As far as noise goes can’t hear any air leaks anywhere turbo whistle sounds normal

 

Originally truck had 80 mm turbo we tried a 78 as well and no difference

 

I know you mentioned checking the CAC and piping. Did you pressure test it? Doesn't CAT use a square cut O Ring on the turbo outlet? Maybe it's missing.

 

I would plug it off at air filters pressurize it on left side and look the entire system for leaks not just the CAC and boots. Be surprised what you’ll find


And start all over like it’s not been looked at. It’s an air problem not a tuning or other issue turbo size exhaust housing etc is fine it’s either not getting enough air or loosing it. Trying 2 different turbos eliminates a bad new one.

For giggles look at the compressor wheel of both just to be sure you’re not getting any missed debris.

I’m also gonna put this out there I’m hearing lots of checked that that’s not it……but you’re missing something I can promise you. High egt is always an air problem be it not enough fresh air, turbo not producing enough air for one reason or another(exhaust leaks or bad exducer wheel banged up compressor etc) or a leak on pressure side period.

 

Can there possibly be shrapnel lodged in intake or a port that is restricting flow? Just wondering if that may be possible. Have seen it in a turbo’d BBC 454 once.