How to Replace Motor Mount? | Steps, Costs & Pro Tips

Replace a motor mount: support the engine, remove old mounts, install new ones torqued to spec. Takes 1–2 hours for an intermediate DIYer.

A worn motor mount turns every stoplight into a shake-and-rattle event, but how to replace motor mount yourself is a straightforward driveway job. When the engine thumps against the firewall during acceleration or the transmission rocks under braking, the rubber-and-steel mounts that hold your powertrain in place have given up. Replacing them is an intermediate-level task — doable with a jack, basic tools, and patience. Here’s exactly what it costs, what you’ll need, and the full sequence without shortcuts.

What Does A Motor Mount Replacement Cost?

Motor mount prices vary by vehicle type and mount design. Basic steel-and-rubber mounts run $10–$150 per unit, while hydraulic or active mounts cost $50–$200 per unit. Labor adds $100–$450 per mount at a shop, but DIYers skip that entirely. Top-mounted mounts take about 30 minutes; mounts buried under intake manifolds need 2 hours or more.

Some vehicles stack the job. If you’re working on a Honda Civic of a similar vintage, our roundup of tested 07 Civic motor mounts covers what fits and what to avoid.

Step-By-Step Motor Mount Replacement Guide

Every motor mount swap follows the same sequence. These eight steps cover the standard process for most US-market cars.

1. Check clearance first. Verify engine clearance against the firewall before lifting anything. Raising the engine without this check can tear radiator hoses or AC lines.
2. Support the engine. Place a floor jack with a wood block under the oil pan — never jack directly on the pan itself. Disconnect the negative battery wire to prevent electrical shorts.
3. Loosen the engine-to-mount bolts. Use a long extension with a universal joint from above. Common sizes: 17mm for Honda through-bolts, 14mm deep-well for Honda inner fender and engine bolts.
4. Remove the frame-side bolts. Crawl under the vehicle to access the mount-to-frame bolts. On GM K2xx trucks, loosen all chassis-side bolts before prying the engine for clearance.
5. Extract the old mount. Jack the engine up incrementally until the mount pulls free. Transfer any heat shields or drip shields from the old mount to the new one.
6. Install the new mount. Thread the frame-side bolts first, then lower the engine into position. This sequence makes alignment much easier.
7. Tighten everything. Lower the engine fully onto its mounts, then torque all bolts to specification.
8. Handle special cases. Front-wheel-drive cars almost always have a third dog-bone mount. For a Honda Odyssey, remove the rear exhaust header Y-pipe and vacuum hose before reaching the rear mount. Mercedes may need intake components or underbody panels removed first.

The full procedure — with torque specs for specific makes — is documented in Mobil’s motor mount replacement guide.

Common Mistakes To Avoid

Even experienced DIYers trip over these six gotchas:

• Skipping engine support. A dropped engine can rupture the oil pan or damage the transmission bell housing. Wood blocks on a jack are cheap insurance.
• Reusing aluminum bolts.
• Over-tightening. Hydraulic mounts compress permanently when over-torqued. Follow the spec, not your arm strength.
• Forcing alignment. Pry bars can crack a new mount in seconds. Massage the engine into position gently.
• Ignoring adjacent mounts. One failed mount means the others worked harder. Inspect all mounts while you’re under there.
• Skipping the clearance check. Lifting the engine without checking firewall clearance is how radiator hoses and AC lines get torn.

FAQs

Can I drive with a broken motor mount?

Short distances at low speed, but it’s not safe. A snapped mount lets the engine shift enough to snap coolant hoses, bind the throttle cable, or damage the radiator fan. Replace it before secondary damage costs more than the mount itself.

Do I need an engine support brace or can I use a jack?

A floor jack with a wood block works for most vehicles. Mercedes and some luxury cars require a dedicated engine support brace to avoid alignment damage to the subframe — a jack won’t provide the same stability in those tight engine bays.

Should I replace all motor mounts at once?

Not always required, but recommended. When one mount fails from fatigue, the remaining mounts have absorbed extra stress and are likely worn too. Replacing all at once saves doing the job again in six months.