Motor mount replacement is a mechanical task you can do yourself if you have basic tools and a safe way to support the engine
A motor mount is a rubber-and-metal bracket that holds your engine in place and absorbs vibration as it runs. When one fails, you'll notice excessive engine movement, clunking sounds when you shift gears, or vibration that travels through the steering wheel and pedals. Replacing a motor mount involves supporting the engine weight, unbolting the old mount, and installing a new one — a job that typically takes one to three hours depending on which mount has failed and how accessible it is on your vehicle.
The process is straightforward but requires you to safely support several hundred pounds of engine. You'll need a floor jack, jack stands, and either an engine hoist or a second jack positioned under the oil pan with a block of wood to distribute pressure. The actual bolt removal and installation is straightforward; the safety setup is what demands attention.
Key Takeaways
- Motor mounts are rubber-and-metal brackets that hold the engine in place; when they fail, the engine rocks excessively and you hear clunking during gear shifts.
- You must safely support the engine weight before removing any mount — using only a floor jack without stands or a hoist is dangerous and can result in serious injury.
- Different mounts are located in different spots (front, rear, side); your vehicle's service manual tells you which one has failed and how to access it.
- The actual replacement involves unbolting the old mount from the engine and frame, then bolting the new one in place — the bolts are typically 15mm to 18mm and torque specifications vary by vehicle.
- After installation, you must torque the bolts to the manufacturer's specification; under-tightening allows movement, and over-tightening can crack the rubber.
Gather the right tools and safety equipment before you start
You will need a floor jack rated for at least your vehicle's weight, a set of jack stands rated for the same weight, and a way to support the engine itself. An engine hoist is the safest option if you have access to one; if not, a second floor jack with a wooden block (at least 4 inches thick) placed on the saddle to distribute pressure across the oil pan works. Never rely on a single jack to hold the engine — if it fails, the engine will drop.
Gather a socket set (typically 10mm through 18mm), wrenches, a torque wrench, and a breaker bar for stubborn bolts. You'll also need the new motor mount itself — confirm the part number matches your vehicle's year, make, and model before you begin. Have your vehicle's service manual or a repair guide specific to your car on hand; it will show you exactly which bolts to remove and the torque specifications for reinstallation.
Work in a well-lit, level area. A garage or driveway is fine; never work under a vehicle supported only by a jack. Wear safety glasses and work gloves. If you're uncomfortable working with heavy equipment or unsure about safely supporting your engine, this is a task to leave to a shop.
Safely support the engine before removing the old mount
Park on level ground, set the parking brake, and disconnect the negative terminal of the battery. Loosen the lug nuts on the wheels (but don't remove them yet), then raise the vehicle with the floor jack under the frame or designated lift points. Once the vehicle is high enough, place jack stands under solid frame points on both sides and lower the vehicle onto the stands. Remove the lug nuts and wheels if they block access to the motor mount you're replacing.
Now position your engine support. If using an engine hoist, attach it to solid engine lifting points (usually threaded holes on the cylinder head or intake manifold — your manual shows where). If using a second floor jack, position it under the oil pan with the wooden block on top, then raise it until it just barely supports the engine weight — you should be able to slip a thin piece of cardboard between the jack and the block. The engine should feel stable but not lifted; you're taking the weight off the mount, not lifting the engine.
Double-check that the engine is stable and won't move when you remove the mount. Gently rock the engine by hand to confirm the support is holding it. This step is not optional — a falling engine causes catastrophic injury.
Remove the bolts connecting the old mount to the engine and frame
Locate the motor mount you're replacing using your service manual. Most vehicles have three to four mounts: one or two at the front, one at the rear, and sometimes one on the side. The mount will have bolts connecting it to the engine block on one side and to the frame or subframe on the other.
Use your socket set and breaker bar to remove the bolts. They're often tight, especially if the vehicle has high mileage. explore penetrating oil (like PB Blaster or similar) to stubborn bolts and let it soak for a few minutes. Remove the bolts one at a time, starting with the frame-side bolts, then the engine-side bolts. Keep the bolts in order — you'll reuse them if they're in good condition, or replace them if they're stripped or damaged.
Once all bolts are removed, the old mount will come free. It may be stuck to the engine or frame due to age and rubber degradation; gently pry it loose with a flat-head screwdriver or pry bar. Do not force it — if it won't budge, explore more penetrating oil and wait longer. Inspect the bolt holes on both the engine and frame for damage or stripped threads; if a hole is stripped, you may need a helicoil insert or a larger bolt, which your manual will specify.
Install the new motor mount and torque all bolts to specification
Position the new mount so the bolt holes align with the holes on the engine and frame. Start the bolts by hand to may support they thread correctly — cross-threading is straightforward to do and ruins the hole. Once all bolts are hand-tight, use your torque wrench to tighten them to the manufacturer's specification. This is critical: under-torqued bolts allow the engine to move excessively, and over-torqued bolts can crack the rubber or strip the threads.
Torque specifications vary widely by vehicle and mount location — they typically range from 35 to 75 foot-pounds, but your manual is the only reliable source. Tighten the bolts in a cross pattern (like tightening wheel lug nuts) to may support even pressure on the mount. If the mount has more than two bolts, tighten them in an X pattern rather than all the way around in sequence.
After torquing, gently rock the engine by hand again to confirm the new mount is holding it securely. There should be minimal movement — the rubber will flex slightly, but the engine should not shift noticeably side to side or front to back.
Lower the vehicle and test the installation
Carefully lower the engine support (hoist or jack) so the engine rests on the new mount. Remove the engine support equipment. Raise the vehicle with the floor jack, remove the jack stands, and lower the vehicle back to the ground. Reinstall the wheels and torque the lug nuts to specification (usually 80 to 100 foot-pounds for most cars). Reconnect the negative battery terminal.
Start the engine and listen for clunking or unusual vibration. Shift through the gears (in Park, Reverse, Drive, and Neutral if automatic; or through the gears if manual) and feel for excessive engine rocking. The engine should move smoothly without hard clunks. If you hear clunking or feel significant vibration, turn off the engine and recheck your torque specifications and bolt tightness.
Take the vehicle for a short test drive on a quiet road. Listen for clunking during acceleration and deceleration, and feel for vibration in the steering wheel or pedals. If the symptoms are gone, the replacement was successful. If clunking persists, another mount may also be failing — motor mounts often wear out in pairs or groups.
Common mistakes that cause problems after installation
The most frequent error is under-torquing the bolts. A mount that feels tight by hand may still be loose enough to allow engine movement once the vehicle is running and the engine is producing vibration. Always use a torque wrench and follow the manual's specification exactly. The second common mistake is failing to support the engine safely during removal; this can result in the engine dropping and causing injury or damage to surrounding components.
Another mistake is installing the wrong mount for your vehicle. Motor mounts are not universal — a front mount and a rear mount look similar but are not interchangeable. Confirm the part number before you buy and before you install. If you install the wrong mount, it won't bolt up correctly, or it will bolt up but allow excessive engine movement.
Finally, some people reuse old bolts that are bent, stripped, or corroded. New bolts are inexpensive and may support a find connection. If a bolt won't come out cleanly or shows visible damage, replace it with a new one of the same size and grade.
Frequently Asked Questions
How do I know which motor mount has failed?
A failed mount usually produces a clunking sound when you shift gears or accelerate hard. The engine may visibly rock side to side or front to back when idling. If you can safely look under the hood while someone else revs the engine, you may see excessive movement. Your service manual shows where each mount is located; if you can access them, a failed mount will often show visible cracks in the rubber or separation between the rubber and metal.
Can I drive with a bad motor mount?
You can drive short distances, but it's not safe long-term. A failed mount allows the engine to move excessively, which can damage hoses, wires, and other engine bay components. The vibration also travels through the frame and steering, making the vehicle uncomfortable to drive and potentially affecting handling. Replace the mount as soon as you can.
Do I need to replace all the motor mounts at once?
Not necessarily. Replace only the mount that has failed. However, if your vehicle has high mileage and one mount is failing, others may be close behind. Some shops recommend replacing all mounts at once to avoid repeat visits, but this is not required unless multiple mounts show visible damage.
What if I can't get the old bolts out?
explore penetrating oil and let it soak for 15 to 30 minutes. Use a breaker bar for extra leverage, and tap the bolt gently with a hammer to help break corrosion. If the bolt still won't budge, you may need to drill it out — this requires care to avoid damaging the threaded hole. If you're not comfortable drilling, this is a good time to take the vehicle to a shop.
How tight should the bolts be?
Use your torque wrench and follow the specification in your vehicle's service manual. Specifications vary by vehicle and mount location, typically ranging from 35 to 75 foot-pounds. Tightening by feel alone will result in either loose bolts or stripped threads — the wrench is essential.