07 int cummins isx

The EGR valve being stuck partway open won't throw a code, since the sensor on the motor reports that it's working right. The turbo can be absolutely fine, but if the actuator's going bad, that dumb VGT turbo can't change configuration fast enough to respond to changing throttle conditions, sometimes causing that "ISX turbo chirp" that these engines are sorta known for. I'm assuming this is YOUR truck, so I'll just quickly mention that there are things you can have done at some diesel shops that will eliminate all EGR related problems permanently, but are not cool to discuss here.

 

$990 for an EGR valve for an ISX? Geez, mine used to go through them so often I carried a spare one in the jockey box, and I don't remember EVER paying that much. You could maybe get away with having it taken off and cleaned. Has your fuel mileage taken much of a hit? When my EGR valve was on its way out, the hit was something like 2-3 tenths. When you go to start up the truck, do you wait to hear all of the whirrs and clicks before you fire it up? There were a few times that mine started coughing just because the valves and actuators didn't cycle all the way before I started it.

 

The valve may not be an issue, If the sensors are sooted up the valve will open too far. And since the sensors are reporting screwy values the ecm tells the turbo actuator to move into a range where the engine isnt making enough exhaust to spool it so it stalls, thats the cough you're hearing.The ecm "thinks" its under a load that it isnt and adds fuel that it cant burn. Its a big downward spiral.

Thats why I said to check all your egr related items. The ISX is a finicky motor, when its right its great but you have to do certain things to keep it right.

 

I think you're onto something with the sensor. Seems to me I had that problem a time or two as well.

 

just wondering how everything turned out