2021 GMC Sierra 1500 · symptom sheet
Engine knocking or ticking
- 39owner reports
- 58,522median miles
- 0involved a crash
Newest report Sep 9, 2026 · checked Oct 2, 2026
39 of the 126 reports of engine failure on the 2021 Sierra 1500 describe engine knock.
Part of Engine failure, knocking or rod bearing (126 reports) · also: engine seized
Tick what matches of 39 reports
Engine knock on other Sierra 1500 years
Report counts are for each model year on its own, so a newer car has had less time to collect them. Model years with too few reports of it for a sheet: 2014, 2015, 2016, 2017, 2018, 2019, 2023, 2024, 2025, 2026.
What got replaced
Owners who name the part that was replaced mention the rod bearing (4 reports).
Recalls and investigations
One recall on the engine covers the 2021 model year. A recall on the same system isn't always the same failure, so read the defect text.
The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure.
All 7 recalls on the 2021 GMC Sierra 1500, with the owner complaints on each recalled system
NHTSA investigations into the engine on the Sierra 1500
Loss of motive power due to engine failure post recall remedy. Open.
Loss of motive power due to engine failure post recall remedy. Closed aug 20, 2026.
Loss of motive power due to engine failure. Open.
Loss of motive power due to engine failure. Closed oct 23, 2025, led to recall 25V-274.
When it happens
The middle half of failures fell between 20,000 and 88,000 miles, from the 21 reports that gave a mileage.
Is this a known problem?
The manufacturer has sent NHTSA 1 service bulletin or notice for the 2021 GMC Sierra 1500 that deal with this problem. Newest first.
Federal rules make a manufacturer send NHTSA a copy of any notice about a defect that goes to more than one dealer or owner. Most of these are service bulletins, the repair instructions manufacturers send to dealers. NHTSA generally leaves safety recall bulletins out of this file, and recalls are listed separately.
Service Update. Certain vehicles may present a broken engine valve spring. This may cause the engine to run rough, an engine knocking or ticking noise, a check engine light illumination, or a possible vehicle stall.
What owners wrote
“Driving on the highway lost proportion/acceleration, loud knocking coming from the engine”
Filed Aug 28, 2026
“I'm not sure if they've pulled it out yet. They said two weeks to get motor. Engine started shaking and then started knocking. Had wrecker take it to GMC dealer they said it needs an engine. It is a 2021 6.2 carbon pro 1500 Sierra AT4 it did not come up on recall list and I don't know why? it obviously the same problem.”
Filed Jul 18, 2026
“The engine has a knocking sound. I took it into the dealer and they replaced the exhaust system thinking that was the problem. However, the knocking still happens intermittently. I have video documentation of the noise.”
Filed Jan 20, 2026
“The engine is knocking and running rough. I took it to Christian Brothers Automotive in Newnan Ga and the advised engine replacement.”
Filed Nov 28, 2025
Should you keep driving it?
This page can't tell you that. 0 of 39 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.
File your own report with NHTSA. Complaint counts are how a problem gets an investigation. How reports land on this sheet.
Guide Paid for this repair before a recall covered it? How recall reimbursement works
Other problems on this car
- Check engine light or misfire 104 reports
- Engine stalls or loses power while driving 88 reports
- Engine overheats or leaks coolant 53 reports
- Transmission shudders, slips or shifts hard 43 reports
- Infotainment, screen or backup camera fails 26 reports
- Engine rattles or ticks 26 reports