How To Tell If Your Engine Mounts Are Bad


Being such a critical component, your car’s engine gets special treatment when being bolted into your frame.  The engine and transmission are all connected to the body with a series of rubber bushings called mounts.  Each engine mount or transmission mount is specially designed to absorb load, protect the mounting bolts and brackets, and insulate the car from vibration.  That way, your horsepower can go straight to the ground, instead of prying your engine out of the engine bay.  Since they are made of flexible rubber, they naturally deteriorate, causing bad things to happen.

Lifting and Banging

Usually around 100-150k miles, you’ll start to notice some strange feelings when you pick up the pace on the road.  This is especially true if you have a manual transmission car.  When the mounts are really bad, the engine will use the axles like a lever to try and lift itself up.  When the engine shifts gears, or you lift off the gas, the engine will fall back down and result in a bang.  This motion will further tear the mounts and leave your engine freedom to rumble and bang around under the hood.  The video below is a good demonstration of what this actually looks like.

Damaging Effects

There’s more than just an uncomfortable feeling when you drive around with bad engine mounts, however.  This extra movement is bad for everything attached to the engine, including CV joints that are moving more than they are designed to, intake and exhaust tubing, wiring harnesses, fluid lines, and shift linkages.

If you have a bad transmission mount, expect your shifts to feel imprecise.  Occasionally this will be so bad you will fail to find gears under heavy torque loads (think stop light launches in 1st gear).  Modern main engine mounts (the ones under the engine taking most of the load) are usually filled with hydraulic fluid.  These hydraulic engine mounts are designed to provide extra cushioning, to insulate the cabin from vibration.

To the right is a photo of one of these hydraulic mounts, where you can clearly see a metal cable attached around it.  This is to limit the movement of the engine in case the mount breaks, to prevent damage to connected components.  When they get old, the mounts can break or tear, causing leaks and usually separation due to lack of solid rubber.

Vibration at Idle

When engine mounts go bad, in addition to the flopping and banging when applying torque, you will notice an increase in vibration at idle.  When you do, it’s a good idea to test the mounts in your car by holding the brakes on and applying throttle.  You can observe if the engine is moving around a lot, usually more than an inch of movement is an indication to start inspecting mounts.  Bad engine mounts will look torn, broken, or separated.

A New Direction

A few automobile manufacturers have recently gotten fancy with their engine mounts, like the one shown below.  We noticed that there were actual electrical connections coming out of these, which is pretty curious when you understand the job of an engine mount is to be a large bushing with a few bolts through it.  These mounts can change their stiffness based on RPM.  They are a soft cushion at idle, but when you hit the gas, they stiffen, allowing more feedback and a tighter feel.  There are a number of approaches to the active engine mount, including Lexus using a counter vibration device to work like a noise cancelling headphone, as well as non-US BMW Diesels using vacuum controlled active mounts that soften at idle due to the inherent vibrations of that type of engine.  If they don’t hold vacuum then they are not good.

Audi’s dynamic engine mounts allow variable stiffness

So if your car has over 100k miles on it, start paying attention to the way the engine feels.  Does it vibrate?  Do you hear or feel a physical bump or bang when you lift off the throttle?  If so, it’s time to replace engine mounts before it gets so bad that you damage other parts.  eEuroparts.com carries engine mounts for nearly every car we support, and some are more common to replace than others.  If your car has a messed up engine mount that we don’t currently have on the website, CONTACT US!  We will have it up on the site in no time so you can get your parts fast.

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20 thoughts on “How To Tell If Your Engine Mounts Are Bad
  1. Soh

    Dear Sir,

    Appreciate if you could assist to explain for the below:

    1. An Audi A5 was sustained badly accident impact on rear portion(the impact causes tailgate, bumper rear & rear panel require for replacement), is there any possible that the impact will cause the engine mounting RH & LH failure?
    2. What is the life period for a new engine mounting?

    Audi A5, year made 2009, odometer clock 54067KM.

    • Adam Goral

      A new engine mount should last around 80-100k miles, however an accident is capable of prematurely breaking these mountings. Generally, this usually happens only after the mounts have aged somewhat, and have been weakened over time. With such a low mile car I would be surprised if your Audi has broken engine mounts, but would not rule it out, especially if you have the electronic engine mounts described in the article, which are a little more delicate. Open the hood and with the car in park (or 1st gear), and your foot on the brake, give it throttle in both forward and reverse gear. If the engine moves around like in the video, you will need new engine mounts.

    • Stephen Andersen

      I have a 2005 ford Ranger 2.3. 86 k mechanic told me my mounts were all good but still having all of the symptoms ofor broken mount. sometimes when I shift to r and back to d i can feel one side of the truck lift and lower. vibration while on idle in the cab and you.can hear the dash vibrating . sometimes the transmission is kinda rough time when shifting could the mounts still be bad when a mechanic says they are fine. or can they be worn out but not broken or maybe the transmission mounts is bad what are you thoughts

      • Adam Goral

        If you are feeling these symptoms and the mechanic told you the vehicle is totally fine, I think it might be time to see a better mechanic. That sure does sound like a bad engine or frame mount somewhere. Sometimes mounts can be broken and look fine as they sit, but separate when put under load. Identify all the mounts that you can find, and have someone apply a slight amount of throttle in drive or reverse while standing on the brake. You should be able to see if something looks askew. A crowbar can also be used to lever mounts to view separation.

  2. Robert tunesi

    I have alot of engine movement on my Hyundai Amica when the revs are low it feels like it’s miss fireing could this be because my engine mounts are worn could it affect my engines performance when revs are high it’s fine it’s only when I slightly put the revs on it seems to miss fire abit and I thought it was because the engine mounts where worn can you help please

  3. Scott

    Hi I have a vauxhall vivaro van. I had a car hit the side of my front bumper at around 25mph straight after the engine started vibrating badly, could this have damaged the engine mounts

  4. Mark

    When I drive between 45 and 55 MPH my car vibrates, above and below those speeds it drives fine. I took it in and they balanced and rotated my tires and that didn’t fix it. I took it in for a transmission flush and fill and they noticed an engine mount was broken (which I never even told them I had symptoms of anything). I guess we will see if that fixed my problem!!

  5. Nicole Jones

    I have a 2005 Nissan Maxima and when I shift the car in reverse and drive it jerks and I when I excelerate it’s kinda sluggish. A guy “mechanic” says it’s the motor mount, I was thinking it was the transmission. I have to get other opinions.

    • Adam Goral

      Is it an automatic transmission? When was the last time you changed the fluid? Sounds like a combination of old fluid and worn mounts, but hard to judge without seeing it in person.

  6. Theeban

    Hi, I have purchased two BWM vacuum hydraulic mounts. I have tested them prior to fitting and they both don’t hold any vacuum. Do you know if this is normal, or if they should be holding vacuum. Any help would be appreciated

      • Theeban

        Hi Adam, yes this is for a non-us market car. They were both purchased brand new from BMW, I didn’t want to fit them knowing they didn’t hold vacuum. I think I should get them returned. Thanks for the advice.

        • Adam Goral

          Good luck, based on what I know they should hold vacuum, but two brand new mounts from BMW…the likelyhood of them both being bad is very slim to nil. Keep me updated if you end up with a set that does. Thanks.

  7. Sonny

    Hi Adam, Mechanic replaced my car’s busted transmission (auto) with an after mart unit. Now there is more engine noise inside the car and I can feel more vibration than before. Could this be engine mounting problem or the transmission not installed properly? Noise and vibration more pronounce when gear is engaged. Less on neutral. Thank you for your advice.

    • Adam Goral

      It is quite possible that the engine mount was stressed or broken during installation or removal, when doing a job like this it is always a good idea to replace these mounts with new. You’re already spending the money, you might as well spend the few extra dollars for new mounts. After all of this, I think that it might just be the nature of the new transmission. You said aftermarket but I assume you mean rebuilt. That means that many parts were used from the original core. The best option would be to just kindly ask the mechanic about the new vibration and noises, they did the work after all.

      • Shawn

        Hello
        I have a 2008 bmw 535xi
        I know I have a bad right motor mount
        Can the bad motor mount cause an issue when making a left turn slowly
        I feel a vibration only on sharp left and the axel seems to be in fine shape

        • Adam Goral

          If the axle is for sure in good shape, then yes it sounds like an engine mount, or quite possibly sub-frame or differential mounts. You can use a crowbar and put pressure on your bushings and mounts to see if there is excess play. Also check your wheel bearings while the car is in the air.

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