A Guide to Replacing Engine Mounts on Your 2015-2019 GMC Sierra
Stop the shaking and clunking by choosing the right replacement engine mount for your truck.
- A common issue for 2015-2019 Sierras is idle vibration caused by failed engine mounts, as documented in TSB 17-NA-166.
- For a factory-smooth ride, OEM hydraulic mounts are recommended; budget aftermarket mounts are typically solid rubber and may increase vibration.
- It is critical to replace both engine mounts at the same time and ensure they are properly settled to fix the known vibration issue.
- Expect a professional replacement to cost between $550 and $1070, depending on the parts used.
Is Your Sierra Shaking at Stop Lights? It Could Be the Engine Mounts
A common complaint for the 2015-2019 GMC Sierra is a noticeable vibration or rough idle, especially when the truck is in Drive but stopped at a light. This issue is so common that General Motors issued a Technical Service Bulletin (TSB 17-NA-166) for it. The bulletin explains that the original engine mounts can "ground out," transmitting engine vibrations directly into the frame and cabin. Other signs of failure include clunking noises when you accelerate or put the truck in gear, and visible engine movement when you rev the engine.
🎬 Watch: How to spot the symptoms of failed motor mounts.Known Issue: TSB for Engine Vibration
GM released Technical Service Bulletin #17-NA-166 for rough idle and vibration in 2015-2019 Sierras. The official fix involves replacing both engine mounts with an updated design and following a specific procedure to settle the mounts correctly. 🎬 Watch: Pro tips for a successful motor mount replacement. If you only replace one mount or don't follow the settling procedure, the vibration may not be resolved. No safety recalls have been issued for the engine mounts.
Choosing the Right Aftermarket Engine Mount
When shopping for new engine mounts, you have a choice between original equipment (OEM) and aftermarket brands. For this specific truck, the choice makes a difference in ride quality.
- OEM (Original Equipment Manufacturer): The GM-specified mounts, including the updated design mentioned in the TSB, are hydraulic. This means they are fluid-filled to absorb the maximum amount of vibration. They offer the best performance for a smooth, quiet ride but come at a higher cost.
- Aftermarket Brands (e.g., Anchor, DEA, Westar): These brands provide a much more affordable option. However, most standard aftermarket mounts are solid rubber, not hydraulic. While they will secure your engine properly, they generally do not dampen vibrations as effectively as the OEM hydraulic mounts. Some owners report being satisfied with the value, while others notice an increase in cabin vibration after installation. These are best considered economy-grade options.
Engine Mount Replacement Cost for 2015-2019 GMC Sierra
The total cost depends on whether you do the job yourself and the type of parts you choose. Replacing both mounts at the same time is highly recommended.
| Part/Service | Estimated Cost |
|---|---|
| Shop Labor | $390 - $570 |
| New Aftermarket Mounts (Pair) | $145 - $225 |
| New OEM Mounts (Pair) | $300 - $500 |
| Total Professional Replacement (Aftermarket) | $535 - $795 |
| Total Professional Replacement (OEM) | $690 - $1070 |
Frequently Asked Questions
How many engine mounts does my Sierra have?
Your 2015-2019 GMC Sierra has two main engine mounts (left and right) and one transmission mount, which supports the rear of the powertrain. The engine mounts are the ones most commonly associated with idle vibration issues.
Is it hard to replace Sierra engine mounts?
It is a moderately difficult job. The main challenge is that you must safely lift and support the engine with a jack to remove the old mounts. Access to the bolts can be tight, especially on 4WD models where the steering shaft and front differential are in the way. It is considered a feasible DIY for someone with mechanical experience and the right tools.
🎬 See this step-by-step walkthrough for replacing your Sierra's mounts.What happens if I don't replace a bad engine mount?
Ignoring a failed engine mount can lead to more serious problems. The constant, excessive engine movement can put stress on other parts like belts, hoses, and the exhaust system, potentially causing them to fail. In severe cases, it can also damage the transmission.
Why does my truck only vibrate in Drive, not in Park?
When your truck is in Drive, the engine is under load and trying to move the vehicle forward, even while you are holding the brake. This engagement causes the engine to twist slightly, and if a mount has failed, it allows the vibration to transfer to the frame. In Park or Neutral, the engine is not under the same load, so the vibration is often not noticeable.
Helpful Videos
Technical Specifications
OEM Part Numbers: 85579396 85579395 23277115
The 2015-2019 GMC Sierra uses two hydraulic engine mounts (left and right) and one transmission mount. The engine mounts attach the engine block to the vehicle's frame. The left (driver side) mount is often the first to fail due to engine torque rotation.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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