About 20 years after the launch of the 6.6-liter Duramax V8, GM’s 3.0-liter Duramax inline-six turbodiesel arrived in 2019 with a promise to deliver “outstanding fuel economy, great horsepower, and responsive torque.” Those have been fulfilled to this point, with the engine producing as much as 305 horsepower and 495 pound-feet of torque. In its best guise, the three.0 Duramax averages a goodly 26 mpg, so it’s little surprise that it found its way right into a handful of GM models, including the Chevrolet Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Cadillac Escalade. Later, it dropped the diesel ahead of the 2025 model 12 months as a result of insufficient demand.
We found the oil burner to be perfectly nice once we drove a 2024 Silverado ZR2 with the three.0-liter Duramax engine, because it suffered no turbo lag and convinced with its smooth power delivery and willingness to deliver loads of low-end torque. Not to say, the Duramax diesel engine can tow as much as 13,300 kilos — it gets a maximum rating of 8,700 kilos when beneath the hood of the ZR2 — meaning it might be a really capable towing option in the event you’re seeking to pull large boats or travel trailers. It is a tremendous engine, but it could experience plenty of problems, with some owners taking to discussion sites to complain about issues mostly linked to the diesel exhaust fluid (DEF), oil leaks, and frustrating crank start issues.
Prolonged cranking times are amongst the most important faults afflicting the first-generation 3.0 Duramax LM2 engine
In keeping with a Silverado Sierra forum post from Smell-U-Later, the three.0 Duramax diesel engine can experience long cranking times on initiate — as much as 10–20 seconds. Many drivers admit that they had encountered this problem at the very least once, with their vehicles either taking a protracted time cranking before starting or refusing to start out altogether. One owner of a 2021 Silverado 1500 RST 3.0 Duramax Turbo Diesel, Brian, while commenting on Automotive Complaints, noted that this problem is intermittent and might occur randomly at any time and at any mileage.
Faulty camshaft position exciter wheel is one of the common reasons for the three.0 Duramax engine long cranking time issue. Some factory-fit camshaft position exciter wheels in certain Chevy Silverado 1500, Tahoe, Suburban, GMC Sierra, Yukon, and Cadillac Escalade models are said to reach bent or warped. In such state, they will disrupt the signals being relayed to the engine control unit (ECU), thus impacting the timing of fuel injection. Normally, fixing this issue requires replacing the camshaft trigger wheel, a job some owners have said takes 40 hours or more to finish, because it often involves taking the cab off to permit for correct access.
Damaged camshaft position exciter wheel aside, the Duramax LM2 is thought to have issues with bad wiring harness, loose or faulty fuse box, faulty actuators, and defective fuel pumps. All of which may also contribute to the prolonged cranking time trouble. In some cases, the difficulty is solved through an update or software refresh of the engine’s ECU. One other bit of fine news is that this problem affects only the primary generation LM2 Duramax 3.0, and never the second-gen LZ0 variants introduced within the 2023 Chevrolet Silverado half-ton truck.
Oil leaks and emissions systems problems have also caused some 3.0L Duramax owners grief
Like nearly any combustion engine, the three.0 Duramax inline-six has a rear major seal (RMS), a component that is designed to stop engine oil leaking through across the crankshaft. Nevertheless, some owners have reported that the three.0 RMS is liable to failure, and that it often develops leaks as a symptom. Leaks could be slow or very fast, to the extent that engine oil levels get dangerously low before drivers have time to top up or visit a mechanic. A GM TSB claims this issue occurs primarily as a result of the rear major oil seal moving or severely shifting out of position within the timing chain lower cover, and thus recommends replacing the timing chain lower cover as a fix. Sadly, some have complained that the oil leak problems keep coming back even after repair.
Diesel exhaust fluid (DEF) glitches are something else that 3.0 Duramax owners commonly face. Drivers have complained about their vehicles suddenly developing DEF malfunction and displaying the “Service DEF System” message together with an engine warning light. Typically, limp mode comes on immediately the message is displayed and limits power to avoid further damage to the engine. Some owners have found this to be a symptom of either bad def injector, loose DEF hose, or faulty DEF sensors, but in other cases, mechanics don’t find any issues with the engine, despite DEF warning suggesting possible faults.
This Article First Appeared At www.jalopnik.com
