Motor Mount Service Life

[artbuc]

Re 1999 Toyota Avalon with V6 1MZFE engine and 135k miles

In 2008 at 85k miles, I replaced dog bone and rear motor mount (PITA !!) with factory parts. Front and transmission mounts are original. Getting vibration in steering wheel when stopped in drive or reverse, not so much in neutral. Just wondering how long I should expect front and transmission mounts to last. Thanks.

 

[mehullica]

Put the car in gear & have someone power brake the car in drive & reverse while you stand to the side with the hood open & you'll see the engine shift quite a bit if the front mount by the oil filter is broken. The rear engine & trans mount rarely go bad.

 

[edwardh1]

pull a boat?
driven by teenager?

 

[artbuc]

Originally Posted By: edwardh1
pull a boat?
driven by teenager?


No, no.

 

[LeakySeals]

At that age all rubber is degraded. Dog bone could be gone again. If you're chewing up multiple dog bones yes, front and/or left and right mounts may be gone. Vibrating steering wheel is usually drivers side front lower mount near where the steering gear mounts to unibody. But I'm guessing there's something additional going on. Putting car in gear adds load. Should idle up in gear until you add throttle. If its not the idle will get too low and the engine will vibrate. Clean the idle IACV and TB if you haven't. Take it off the car to clean. Then look for vacuum leaks. Determining if the intake manifold gasket is leaking is not that easy, at that age just replace it. Cheap fix, Not hard.

 

[artbuc]

Originally Posted By: LeakySeals
At that age all rubber is degraded. Dog bone could be gone again. If you're chewing up multiple dog bones yes, front and/or left and right mounts may be gone. Vibrating steering wheel is usually drivers side front lower mount near where the steering gear mounts to unibody. But I'm guessing there's something additional going on. Putting car in gear adds load. Should idle up in gear until you add throttle. If its not the idle will get too low and the engine will vibrate. Clean the idle IACV and TB if you haven't. Take it off the car to clean. Then look for vacuum leaks. Determining if the intake manifold gasket is leaking is not that easy, at that age just replace it. Cheap fix, Not hard.


Don't think I have a driver's side mount next to steering gear. I replaced the intake manifold gasket 4 years ago. The IACV appears to be working well and the engine is running smooth but I'll do some more checking.

 

[zzyzzx]

If you are needing to replace those mounts already, especially more then once with OE parts, I suspect that something else is wrong causing your motor mounts to go bad. I also have no idea what this something else might be.

 

[artbuc]

Originally Posted By: zzyzzx
If you are needing to replace those mounts already, especially more then once with OE parts, I suspect that something else is wrong causing your motor mounts to go bad. I also have no idea what this something else might be.


I am quite sure all 4 mounts are good. The engine barely rocks when I kick it. The 2 I replaced it 08 still look new. Transmission mount has little play in it. At next oil change I may pull front mount to make sure it is tight. Engine running great and idle speed control is right on. I do not have a clue but thanks to all for your help.