at the dealer, we will see......
Dropped off at the dealer on 9/18/25.
Dropped off at the dealer on 9/18/25.
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5,500 miles, in limp mode
- Thread starter TripleB
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Hope all gets fix and no major issues bud.
Shoulda kept the 6.6.
No kidding.... This was my hesitation to get rid of my flawless so far, L5P. All newer diesels have insanely complicated systems; it's not the motors. Already on the raptor and rho forums!!!Shoulda kept the 6.6.
DEALER UPDATE:
The oil pressure control solenoid went bad and forced the truck into limp mode once it was starving for oil. A few days later the part came in, they went to replace it and noticed a large amount of metal debris. The metal debris likely made the OPCS go bad. The amount of metal debris immediately triggered an engine replacement request to GM. GM said dig deeper. The dealer dug deeper and kept finding metal debris, reported back to GM. Waiting on GM final approval for an engine replacement. They think it's a failed crankcase journal washer but would not know for sure unless they broke the engine all the way down. They say it is very rare and rare for any Duramax engine replacement. The dealer has already ordered the engine.
The oil pressure control solenoid went bad and forced the truck into limp mode once it was starving for oil. A few days later the part came in, they went to replace it and noticed a large amount of metal debris. The metal debris likely made the OPCS go bad. The amount of metal debris immediately triggered an engine replacement request to GM. GM said dig deeper. The dealer dug deeper and kept finding metal debris, reported back to GM. Waiting on GM final approval for an engine replacement. They think it's a failed crankcase journal washer but would not know for sure unless they broke the engine all the way down. They say it is very rare and rare for any Duramax engine replacement. The dealer has already ordered the engine.
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They should just replace the truck!
My wife said the same thing. Sent in a request this morning.
Open a case with GMC if not already done so; be very strong with your communication. An engine change at 5000 miles may be a pre-cursor to other undiscovered issues due to perhaps bad build day/date/operator etc.
Not this early!
Thunder_Grey2025
Active member
Were there any signs before that happened?
no, just went into limp mode.
GMC AT4 Forum Photos
GMC AT4 Forum Photos
