Hello, I'm trying to prevent leaving my truck at the dealer for them to diagnose the problem. If I could get some good ideas beforehand, it will minimize my down time.

Issue: I get very high pre-turbo EGTs with stock programming (even with an intake and exhaust). Idle is mid-300s. 55-60 mph cruise is 500-800*. I did a 200 yard WOT and my gauge recorded a 1418* max. Ouch!!!!

With the EGR unplugged the same run reaches past 1200* (8+ psi less boost too). Still too high with an aftermarket exhaust and intake.

So possibilities are: 1) EGT probe isn't 'exactly' centered in the manifold. 2) EGR cooler is plugged/not functioning. 3) others?

Thanks for the comments/help!

 

Are you running any chip or fuel box set on stock? Or is it truly stock?

 

I would say the probe first, but I run a disconnected egr and with pyrometer in the manifold:

1. Idle = 400 or less
2. 75 mph flat= 800
3. WOT, 10% ramp, off-road, 4x4 = 1200 and ran outta room.

Thought it was pretty hot myself, I know my truck runs hotter with the egr connected

 

It's truly stock. I have an AFE stage2 intake and a 4" mbrp exhaust. The cat and muffler remain. I do know that some aftermarket chips start defueling around 1300.

It just doesn't make any sense why I'm so dang hot with stock programming, an intake, and exhaust.

 

What altitude are you at? The higher the altitude, the hotter you will run. Mine would hit 1350 no problem stock tune, aFe intake, and 4” straight pipe.
Ok, this is just me throwing out ideas;
From MY understanding of how the EGR works, it should be closed when you are at WOT, or anything other than idle or cruise conditions, and should not affect the engine at all in your case. Maybe the EGR is sticking? But then again it seems to be closed when you disconcert it. Since it is changing when you disconnect it, it seems that it might be a sensor not working right. You might want to pull the EGR and see if it is dirty, or looks like it might be sticking. The new flash might help you with this also; it eliminates the Exhaust Pressure (EP) sensor, which might me causing the EGR to open when it shouldn’t.
These are just random speculations on my part, so take it for what its worth

 

Thanks. Yes I need to do some investigating. Because that's just too hot. I'm between 4500 and 5000 ft. I can't believe stock programming allows it to get that hot!

So you don't think the EGR cooler could plug up or stop working?

 

Well, from what you describe, just by unplugging the EGR the truck runs a lot cooler, so it has something to do with the EGR. Based upon my speculation, this means one of four things.
1) The EGR might be sticking some (if the EGR was completely stuck, I don’t think you would see a difference from unplugging it). But it might be sticking somewhat.
2) The EGR is being opened when it shouldn’t be. This could be due to a bad sensor. The EGR should only be open at steady state conditions when the EP is reading higher than the MAP.
3) It is something else, and by disconnecting the EGR, the computer is simply detuning the engine (less fuel=lower EGT).
4) Like you said, the exhaust is not being cooled like it should. I can’t see a reason the cooler could become plugged unless something was floating around in your cooling system. I don’t think there is a coolant valve here, but I could be wrong.
From the 6.0 bible, here is a list of sensors that affect the EGR. I would suspect the EGRVP and the EP first. NOTE- I am not a ford tech, nor do I claim to be, if someone would like to chime in you will not insult me by disagreeing-
AP (acc pedal position)
Baro (Barometric Pressure)
EGRVP (EGR valve position)
EOT (engine oil temperature)
EP (Exhaust Pressure), eliminated with new flash
IAT2 (intake air temp #2)
MAF (mass airflow)
MAP (manifold absolute pressure)

On a side note, does anyone know when the boost pressure is higher than the pre turbo exhaust pressure?

 

Thanks for the insight!