2023 GMC TERRAIN Engine Problems

GM Flier PIP6071A - continued engine misfire/chugging/buck/skip under load, going up hills, trying to pass, etc. Was taken to shop January 2025 ~90,000 with these symptoms. Charged for spark plug replacement (visit 1). Taken back January 2026 ~150,000 miles, charged for ignition coil 1 and spark plugs. Immediately returned as problem persisted, spark plugs replaced (visit 3). February 6 2026, same problem as before, spark plugs replaced (visit 4). February 18 2026, currently in shop, problem persisting, trying to say it is the other 3 ignition coils, even after I requested they check O2 sensor and inspect catalytic converter.

The high pressure fuel pump, the car randomly goes into limp mode and stalls and then when cranking it back up in the middle of 635 it hesitates to start, done this 3 times already

GMC Terrain with 12,564 total miles had experienced an engine failure. Under normal driving conditions, the car was sluggish and would not accelerate properly when pulling out into traffic or when getting on the freeway/interstate causing fear for driver safety and causing traffic slowdowns or congestion with a significantly increased risk of crash. While driving to work, the vehicle service engine light turned on and displayed "reduced engine power". Upon investigation the dealership found codes P0011, P0014, P0016, P0017, and quoted "Cylinder 4 intake rocker had fallen off and laying on head, found excessive debris and metal material around rocker 4, Found cylinder 2 intake rocker to be worn sideways. Found heavy damage to intake camshaft. Removed oil filter - found excessive metal in oil filter". Secondary issue, infotainment screen would randomly flash bright white on the right half, causing a major driver distraction. Engine, turbo, and infotainment system were...

The contact owns a 2023 GMC Terrain. The contact stated while driving 15 MPH, the message "Engine Power Reduced” was displayed on the instrument panel. The contact stated that the vehicle the lost motive power in the middle of the roadway. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the high-pressure fuel pump, causing fuel to leak into the oil, resulting in damages to the catalytic converter and Oxygen sensor. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 41,000.

At stop light turning right, the car stalled, cut on and cut back off, cut on and back off with about 30 cars behind me. Sputtering. On the dash board it said “Engine power reduced”. I had to be pushed out a main highway by police, and thankfully my [XXX] daughter wasn’t in the back seat. I have had this car 12 days with 48256 miles on it. I’m extremely concerned with the safety of this car. And when towed was leaking gas like fluid. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Rear main seal leak car has been with dealer since 12/30/24 until present day. No updates other than I may need a engine.

I bought a 2023 GMC Terrian SLE brand new 14 months ago. It has 30,000 miles on it. I was driving down [XXX] and the car turned off. No warning signs! Not to mention The car had no power! I couldn’t even put on my emergency flashers! Me and my 3 year old son luckily were able to make it through a lane of traffic and up the embankment to call for help! I had the car towed to the dealership and they can’t find anything wrong with it! The car is acting normal now but I don’t feel safe in it! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)