EGR Valve Failure Symptoms on Peterbilt and Kenworth
Recognize EGR valve and cooler problems on PACCAR and Cummins platforms: codes, smoke, derate, and the right replacement kit for your VIN.
What does the EGR valve do?
Exhaust Gas
Recirculation (EGR) reduces NOx by routing cooled exhaust back into the intake. The valve meters flow; the cooler drops gas temperature before it enters the charge air path.
Symptoms of a failing EGR valve or cooler
- Rough idle or surge at idle
- Loss of power with active derate
- Excessive black or white smoke on acceleration
- Coolant loss with white exhaust (cooler crack)
- Stored codes for EGR position, flow, or differential pressure
Peterbilt vs Kenworth: what changes?
Cab brand does not define the engine. Confirm whether you run PACCAR MX, Cummins ISX/X15, or legacy Detroit — then match the EGR kit to that engine family and emissions year.
Frequently asked questions
Can I clean an EGR valve instead of replacing it?
Carbon cleaning may help light sticking. Stuck pintles, failed position sensors, or cracked housings require replacement kits.
Should I replace the EGR cooler at the same time?
If you see coolant in the exhaust path, overheating, or cooler leak codes, replace the cooler with the valve kit to avoid repeat derates.
How do I find the correct EGR kit for my truck?
Provide VIN, engine serial, and a photo of the valve tag. Match Peterbilt 389, Kenworth T680, and other models by engine — not by hood brand alone.
Will deleting EGR fix these symptoms?
Emissions deletes are not legal for on-road highway use in the United States and are not supported by Expedia Parts. We supply OEM-style replacement components for compliant repair.
Related on Expedia Parts
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