Motor mount replacement

[tsflstb]

My 1992 NA develops a metallic knock going over bumps after heating up from an hour or so of driving. I don't see any of the suspension bushings going out and the noise seems to be from down at the driver's side motor mount when I bounce on the fender.

I've searched on the replacement process and heard about removing the alternator for the passenger side and maybe the a/c compressor, but not sure if there's enough slack in the exhaust and driveline to jack up the engine and swap out the mounts? I don't have an engine hoist on hand but could borrow one if it is necessary. Another search mentioned removing the cross member, but I'm not sure if that's required.

Just wondering if this is a 2 hour or 2 day job for the average hack before I get started. Everything is stock so I'd replace with OEM mounts.

Thanks.

[itsa300zx]

First attempt? Give yourself a full day. The top bolts are quite tight, I find (especially with the larger size of the OEM mounts). I highly recommend the BDE billet motor mounts over the OEM at similar cost. They are much smaller in diameter, therefore much easier on install, due to the added space. Don't need to lift the engine much, only about 3/4" or so.

Here is a link to the BDE mounts

http://www.bde-performance.com/mounts2.htm

[tsflstb]

Thanks. Are the BDE mounts much stiffer than stock? This is more of a daily commuter car so I'd like to keep it as smooth as possible.

Also, is a floor jack with some wood cribbing under the oil pan OK to lift the 3/4 inch?

[itsa300zx]

I believe they are slightly stiffer, but I felt no difference in vibration between the two.


I would not lift any thing from the oil pan, even with a piece of wood under it. You hear people denting them by placing the engine floors all the time. For me, too much to risk.

[nissanfreak12]

Thanks. Are the BDE mounts much stiffer than stock? This is more of a daily commuter car so I'd like to keep it as smooth as possible.

Also, is a floor jack with some wood cribbing under the oil pan OK to lift the 3/4 inch?

I have used a jack and a 2x4 that is at least the whole length of the pan on many different vehicles, including a Z with no issues. Make sure the mounts are disconnected. If you lift the car by the pan, even with the wood, you will dent it. Just take your time, you will need to lift it at least an inch to get the studs out. Keep it toward the front of motor, by the bend, its more rigid there.

If you still concerned, keep the transmission mount connected and lift at the furthest forward part of the transmission, at the bell housing. It will work, but to me it is just more stress and chances of something breaking is much higher. Again take your time.