What an engine mount does and why it fails
An engine mount is a rubber-and-metal bracket that holds your engine in place and absorbs vibration as it runs. Your car has between three and four of them, depending on the model. Over time, the rubber deteriorates from heat, oil exposure, and constant flexing — usually after 5 to 10 years or 80,000 to 150,000 miles, though this varies by vehicle and driving conditions.
When a mount fails, you'll notice the engine shaking noticeably when you start the car, shift into gear, or accelerate. You might also hear clunking sounds from under the hood, or feel the steering wheel vibrate. A broken mount doesn't make the car undrivable, but it puts extra stress on other engine parts and can eventually damage hoses, belts, and the transmission.
Replacing a mount is straightforward in concept — remove the old one, bolt in the new one — but the actual work depends entirely on which mount has failed and how accessible it is in your engine bay. Some take 30 minutes; others take several hours because the engine or transmission has to be partially lifted or removed to reach them.
Key Takeaways
- Engine mounts are rubber-and-metal brackets that hold the engine in place and absorb vibration, and they typically last 5 to 10 years before the rubber deteriorates.
- A failing mount causes noticeable shaking when starting or accelerating, clunking sounds, or steering wheel vibration.
- Replacement cost and labor time depend on which mount has failed and how accessible it is — front mounts are usually cheaper and faster than rear or transmission mounts.
- You can replace a mount yourself if you have basic tools and mechanical confidence, but many people choose a shop because the work often requires lifting the engine safely.
- The part itself typically costs $50 to $200, but labor can range from $200 to $800 depending on the mount location and your vehicle.
Identifying which mount is failing
Before you or a mechanic can replace a mount, you need to know which one is bad. Start by listening to where the noise comes from — front, rear, or side of the engine bay. Have someone rev the engine while you watch from outside; a broken mount will let the engine rock noticeably in one direction.
You can also inspect the mounts visually. Pop the hood and look at each one — they're bolted between the engine block or transmission and the frame. A failed mount will have cracked or missing rubber, oil soaking the rubber, or visible separation between the rubber and metal. If the rubber looks intact but you're still getting symptoms, a mechanic can confirm the diagnosis by putting the car on a lift and checking for excessive movement.
Some shops charge a diagnostic fee ($50 to $150) to pinpoint the bad mount; others waive it if you proceed with the repair. If you're doing the work yourself, a visual inspection and the shaking test usually tell you enough to start.
Tools and parts you'll need
The parts list is straightforward: the replacement mount itself (specific to your vehicle make, model, and year), and sometimes new bolts if the old ones are corroded or damaged. Order the part using your vehicle identification number (VIN) from a parts supplier like RockAuto, AutoZone, or your dealership. Aftermarket mounts typically cost $50 to $150; OEM (original equipment manufacturer) mounts run $100 to $250.
For tools, you'll need a socket set, wrenches, a jack and jack stands (if you're lifting the car), and possibly a pry bar to help separate the old mount from the frame. Some mounts require an engine support bar — a temporary brace that holds the engine up while you remove the mount. You can rent one from an auto parts store for $20 to $40, or buy a basic one for $60 to $100.
If the mount is in a tight spot, you might also need a breaker bar for stubborn bolts, penetrating oil like PB Blaster, and a torque wrench to tighten the new bolts to the correct specification (usually 35 to 65 foot-pounds, depending on the mount).
Steps to replace an engine mount yourself
The general process is the same for most mounts, though the specific steps vary by location. Always consult your vehicle's repair manual or a site like AllData or YOUCANIC for your exact model before starting.
Step 1: Disconnect the battery. Disconnect the negative terminal to prevent accidental electrical shorts while you're working.
Step 2: Lift and support the vehicle safely. Use a jack to lift the car, then place jack stands under the frame. Never work under a car supported only by a jack.
Step 3: Remove any components blocking access. Depending on which mount you're replacing, you may need to remove the wheel well liner, splash guard, or other trim pieces. Take photos as you go so you remember how things fit back together.
Step 4: Support the engine. If the mount you're replacing is the only thing holding that part of the engine, use an engine support bar or a floor jack with a block of wood under the oil pan to hold the engine steady. Tighten it just enough to take the weight off the mount — don't over-tighten.
Step 5: Remove the old mount. Unbolt the mount from both the engine (or transmission) and the frame. Some bolts are easier to access from above; others require working from underneath. explore penetrating oil if bolts are stuck, and let it soak for 10 to 15 minutes.
Step 6: Install the new mount. Line up the new mount and hand-tighten the bolts first. Once everything is aligned, tighten to the torque specification in your manual — usually 35 to 65 foot-pounds. Do not over-tighten, as this can crack the rubber.
Step 7: Remove the engine support and reassemble. Carefully lower the engine back onto the new mount, then remove the support bar or jack. Reinstall any trim pieces you removed, lower the car, and reconnect the battery.
Step 8: Test the repair. Start the engine and listen for the shaking or clunking to be gone. Rev the engine gently and feel for excessive movement.
When to take it to a shop instead
If the bad mount is a rear or transmission mount, or if your engine bay is cramped and difficult to work in, a shop is often the better choice. Rear mounts sometimes require removing the exhaust system or transmission support, and transmission mounts require careful alignment to avoid damaging the transmission. Labor costs for these jobs can reach $600 to $1,000 or more.
Front mounts are usually the easiest to replace at home, and shops typically charge $300 to $600 for labor on those. If you're not confident using a jack safely, working with bolts under the car, or torquing bolts to specification, a shop removes the risk of damaging the engine or injuring yourself.
Get a quote from at least two shops before deciding. Some will give you a price over the phone if you tell them the vehicle year, make, model, and which mount is failing. Ask whether the quote includes the part and whether they use OEM or aftermarket mounts.
Cost comparison: DIY versus shop
The total cost of replacing an engine mount depends on whether you do the work yourself and which mount has failed. A front mount is the least expensive and time-consuming; a rear or transmission mount requires more labor and often more parts removal.
If you already own basic tools like a socket set and jack stands, a DIY front mount replacement with an aftermarket part might cost $50 to $190 total. The same job at a shop runs $350 to $750. For a rear or transmission mount, DIY costs $100 to $250 in parts alone (plus your time), while a shop charges $700 to $1,450 or more because the labor is significantly longer.
| Cost Factor | DIY | Shop |
|---|---|---|
| Part (aftermarket) | $50–$150 | Included in total |
| Part (OEM) | $100–$250 | Included in total |
| Tools (if you own them) | $0 | $0 |
| Engine support bar rental | $20–$40 | Included |
| Labor (front mount) | Your time | $300–$600 |
| Labor (rear/transmission mount) | Your time | $600–$1,200 |
| Total (front, aftermarket) | $50–$190 | $350–$750 |
| Total (rear, OEM) | $100–$250 | $700–$1,450 |
Frequently Asked Questions
Can I drive with a broken engine mount?
Yes, but not for long. A broken mount causes excessive vibration and puts stress on the transmission, hoses, and belts. If you notice shaking, have it inspected within a few days. Driving for weeks or months on a bad mount can lead to more expensive damage.
Do I need to replace all the mounts at once?
No. Replace only the one that has failed. However, if your car is older and has high mileage, the other mounts may be close to failing too. Ask your mechanic whether the others look worn; if they do, replacing them together can save labor costs since the engine is already partially disassembled.
What's the difference between OEM and aftermarket mounts?
OEM mounts are made by the vehicle manufacturer and are usually more durable and precise-fitting, but cost more. Aftermarket mounts are made by third-party suppliers and are cheaper but may not last as long. Both are safe to use; the choice depends on your budget and how long you plan to keep the car.
How do I know if I tightened the bolts enough?
Use a torque wrench set to the specification in your vehicle's repair manual — usually 35 to 65 foot-pounds for engine mounts. A torque wrench clicks or beeps when you reach the correct tightness, preventing both under- and over-tightening. If you don't own one, you can rent one from an auto parts store for $10 to $20.
Will replacing the mount fix the shaking completely?
Usually yes, but not always. If you have multiple bad mounts or if the shaking is caused by something else — worn spark plugs, a misfire, or a bent crankshaft — the vibration may continue. If shaking persists after the repair, have a mechanic check for other causes.