Engine Mounts

Messages
17
Location
Staten Island , NY
Hello, I was talking with a friend who just changed his Engine mounts on his honda that is 14 years old. He said it helps keep the vibration lower. I have a 1990 toyota corolla sr5 manual that has 160,000 miles. How often should Engine mounts be changed and what is the benefit to it?
 
Messages
2,543
Location
Rochester, MI, US, World
I would say that your friend is somewhat mistaken. Old motor mounts are squishy and less supportive; that is true. But as far as vibrations, I don't think that old mounts would contribute to that at all. If anything, they may lessen idle vibrations, or other vibrations, because of the fact that they ARE softer. But as for when to replace them, it really is a case-by-case scenario. If you are getting "shift-shock", or excessive movement of the motor/transmission assembly when you or the car shift(s) gears, it may be time. Also, engage your parking brake, pop open the hood, and watch your motor (or have a friend look) and see how much it moves when you start the motor, switch gears, etc. My friend had an old Cavalier that had VERY bad mounts. The motor would move back and forth about 3", just from changes in idle pattern! (like on a cold start, as the rpm's drop and the computer slows down the idle and adjusts the air/fuel mixture). I ended up just putting in some polyurethane motor mount inserts in the motor mounts; it firmed them right up! Made them a little firmer than stock mounts when new. This is a much cheaper alternative, and it is likely that something like this is available for your car. The only downside is that you may get a little vibration when the a/c is on (because of the firmer mounts), but the whole driveline is more secure, and you can feel it, especially if you drive a stick.
 
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kon75

Thread starter
Messages
17
Location
Staten Island , NY
Thanks for the reply Klutch9. As far as vibrations go I have none it is pretty smooth. But I cannot do that test because I have a manual 5 speed and not a automatic. I checked the motor mounts and they seem to be on the hard side and not soft to the touch. Where did you buy the polyurethane motor mount inserts?
 
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Messages
2,543
Location
Rochester, MI, US, World
Try putting your car in neutral, and look at your motor, while revving it (not redlining, just short blips of the throttle to like 3k rpm), and see how much your motor moves. Granted, this test doesn't really introduce any engine load, so your motor may not move that much, but it might give you a good idea. But since you have a stick-shift, stiffer motor mounts/inserts can make shifting feel much nicer grin you can buy the inserts online. Two popular companies are Energy Suspension and Prothane, but for certain applications, other companies also make them. Just do a google search for your car and see what products come up. You have a Toyota, so I'm guessing there won't be a shortage of aftermarket parts. Or you could do what I did on my SRT-4, and fill your motor mounts with a liquid polyurethane mix that hardens SOLID. I don't recommend this for a daily driver, since the vibrations at idle can get annoying, as can the panels in your car rattling. But talk about absolutely no engine movement and great shift feel... drive
 
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kon75

Thread starter
Messages
17
Location
Staten Island , NY
thanks again, I will look into those sites you mentioned, and it would be good to improve the shift feel. Is this a job for a DIY or do I have to take it to a mechanic? The motor mounts are not that expensive as I would like to do it myself.
 
Messages
2,543
Location
Rochester, MI, US, World
Motor mounts usually aren't too hard to remove, but it depends. On my SRT-4 and my 2.4l Grand Am, the upper and lower motor mounts were a piece of cake to remove, and to put back on. But my Escort Zx2, from what I remember, had a front and rear setup. I only did the front, and it was "supposed" to be the easier of the two. But it was nearly impossible to get at, no room to turn the wrench, the bolts were rusted shut, and I nearly rounded off both bolt heads. But lots of shouting and many dirty words later, I got it done. Haha. Just be sure to support the motor (usually with a hydraulic jack with a 2x4 on it) on the oil pan BEFORE you remove any of the mounts. Don't jack up on the oil pan, just make contact and "support" it. Either way, the motor will move a tiny bit, so you'll have to wiggle things around a little when re-assembling, but that won't give you much trouble. A long screwdriver pushed through 2 holes can align them real nice thumbsup
 
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Messages
36,516
Location
ME
Soft mounts can make vibrations worse if you hit a resonant frequency. Depending on your car the motor sagging can tweak the exhaust so it rubs on something; THAT will be buzzy and annoying.
 
Messages
2,543
Location
Rochester, MI, US, World
Originally Posted By: eljefino
Soft mounts can make vibrations worse if you hit a resonant frequency. Depending on your car the motor sagging can tweak the exhaust so it rubs on something; THAT will be buzzy and annoying.
Hadn't thought about that.
 
Messages
19,479
Location
Chicago Area
You can do the mount test with a stick shift. Have the parking brake on real good. Rev her up to 1,500 RPM and Let the clutch out to the engagement point in first and reverse. You will see the same engine movement as with an auto tranny.
 
Messages
2,097
Location
kansastan
I don't know about a Yota. But a lot of Hondas have variable damping built into some of the motor mounts, switched by vacuum.
 
Messages
1,583
Location
USA
Originally Posted By: onion
I don't know about a Yota. But a lot of Hondas have variable damping built into some of the motor mounts, switched by vacuum.
The vacuum ones are only for the automatic transmission Hondas
 
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