Chevrolet Suburban
3.0L inline-6 diesel, aluminum block, single turbo — the only I6 diesel in a US half-ton. LM2 (2020-2022): crankshaft reluctor wheel fails, engine cranks without starting. Repair requires cab-off, 40+ labor hours. LZ0 (2023+) got steel pistons, revised turbo, 305 hp / 495 lb-ft. Oil pump sits at rear of the block: transmission-out job for a $30 part. Highway 26-28 mpg empty, 12-14 mpg towing.
Suburban 3.0 Duramax — highway diesel in an SUV
277 hp inline-6 diesel: the most economical Suburban option. LM2 (2021-2022) with early issues, LZ0 (2023+) significantly better. Ideal for high-mileage drivers.
Engine Weaknesses 3
Crankshaft reluctor wheel fails — engine cranks without starting. Repair requires cab removal (40h labor).
Symptoms: Engine cranks without starting, especially cold, intermittent
Seal leaks on early LM2 (2020-2022). Oil spots under the vehicle.
Symptoms: Oil spots under vehicle, dropping oil level
"Service DEF System" warning, limp mode, no-start in extreme cases. Injector, sensor or pump defective.
Symptoms: Service DEF warning, power reduction, limp mode
Vehicle Weaknesses 4
Faulty Vitesco fuel pump power control module can cause intermittent fuel pump failure — engine stalls unexpectedly while driving. GM Recall N212332040 covering approx. 15,000 2021 Tahoe, Suburban, Escalade, Yukon SUVs. Free dealer repair.
Same 10L80 issue as Silverado T1XX. Recall 26V085.
Factory clearcoat fails prematurely — peeling, cracking, cloudiness, flaking and microblistering reported on roof and hood. Class action lawsuit filed against GM. Some 2021 Tahoes showed bare metal and rust bubbling after just 40 months. Cosmetic repair cost significant without manufacturer support.
Instrument cluster blacks out completely while driving — speedometer, fuel gauge, warning lights all disappear. Often tied to the broader electrical issues on this generation. Airbag 'Service Safety Restraint System' warnings also reported.
Explore more
All Chevrolet models Suburban T1XX overview