2018 Chevrolet Colorado: What to check before buying

Transmission shudder dominates. Owners describe a rumble-strip feel, stutter, or hesitation on acceleration, often between 20 and 60 mph and worse on hills or when towing. Reports cluster around 32,000 to 40,000 miles, with a second wave near 90,000 and beyond. A GM bulletin calls for a fluid flush, but dealers often cannot duplicate the problem, decline the work, or flush it without success. One torque converter failure ruined the transmission at 76,000 miles. Keys stuck in park, rear differential clunks, a parked rollaway with 2 injuries, and a crash after all four wheels locked also appear.

Ignition keys that will not turn to off or come out of the column are the most repeated fault, sometimes draining the battery. The touchscreen misbehaves too, with phantom taps, calls put on hold, the backup camera switching on at highway speed, and frozen or foreign-language displays. Wiring harnesses chafing against hot A/C lines cause random warnings, sudden downshifts, and in one case fuel line damage. Doors that lock and unlock on their own, transmission limp mode, and one fire that started behind the rear seat while driving round out the reports.

Power steering cuts out without warning, sometimes in extreme cold, sometimes toggling on and off mid-turn. The wheel can also bind or jam during turns. Failures cluster near 40,000 miles, where owners paid for a new electric steering gear. Some cases trace to chafed wiring that sets off a cascade of stability and steering-assist warnings, and one truck lost engine power along with steering. Dealers often cannot reproduce these intermittent faults. Several reports here again involve keys stuck in the ignition, plus a steering shaft rattle and wheel shake at 35 to 70 mph.

Fuel leaks are the main concern, and one led to a fire under the bed that totaled the truck. On the diesel, a fuel feed line rubs against an A/C component until it wears through, reported around 60,000 to 70,000 miles. Another owner paid out of pocket for a detached high pressure fuel pump that a recall should have covered. Other reports describe cold-start stalling with no codes, a repeatedly blown injector fuse on the 2.8L diesel causing power loss, and a broken flapper in the filler pipe.

Side curtain airbags and seat belt pretensioners fire with no crash. Two reports describe this while driving slowly off road, one of them in 4WD Low. In one crash into a tree line, the airbags did not deploy. Another complaint describes loose metal rattling in the driver door pillar near the side airbag. One owner reports a dealer refusing to perform an airbag recall repair after deciding the truck had been tampered with.

Few reports, but the ones filed are serious. A factory engine block heater is blamed for an engine compartment fire while the truck sat parked and plugged in. On a nearly new truck, an oil cooler line hose failed and emptied the oil quickly, with a check engine light and falling oil pressure as the only warning. On the 3.6L, a cold-start rattle traced to the camshaft timing actuator becomes more frequent with age. One complaint filed here actually describes transmission shudder.

On the ZR2, the Multimatic DSSV rear damper can leak out its fluid, leaving the truck unbalanced off road or when towing. One ZR2 frame bent at the cab-to-bed area after hitting a dip at 25 mph while towing a 2100 lb trailer. Another report describes front end clunking over bumps at very low speed. One complaint filed here actually describes a flickering dashboard and radio, which is an electrical fault.

A hood that bounces up and down while driving persists after a latch adjustment in one report. Another describes the bed sides buckling and rippling at 69,000 miles. The remaining reports are miscategorized: a backup camera screen too bright to see at night, and a mix of dashboard gurgling, high idle at startup, and hood paint flaws. In these cases dealers either could not duplicate the issue or did not repair it.