I've had this problem going on for awhile, and still can't seem to nail it down.

Basically, at idle the engine shakes to a moderate degree. I've checked the compression - it's good. Checked idle, a/f mixture, vac leaks, loose wires... anything that could give it a lumpy idle. Nothing. Besides it actually idles rock steady around 850. No sputtering at all.

Here's the deal tho. I can put my hand on top of the intake and press down and very nearly stop the engine from shaking. So I'm suspecting a loose motor mount. My question is, how can I check it and do I need anything more than a socket wrench to fix it?

Thanks in advance for any help.

 

Grab hold of the engine and shake the **** out of it. :-)

Actually, the mount on the passenger side is the one that usually goes. Go to the drivers side and try to pull the engine towards you. The mount usually severs itself from the cup it sits in, and the engine can be lifted away from the mount.

At 190, 000, they probably both need replacing. You can substitute the convertable mounts for the standard ones if you want stiffer mounts. they're like 30 or 40 bucks each.

ALSO, you might want to check the tranny mount. They could also cause engine vibration.

To change them, your going to need somthing to lift the engine slightly. Other than that, all you need is some wrenches. (12 mm, I think)

 

Difinitley swap them out. Mine were total crap, and it made a huge difference.

 

The engine mounts were replaced by the previous owner at 150K, they still look good, but I haven't crawled under the car yet to give 'em a close look.

Tried your suggestion, Mark. The motor doesn't seem to move noticeably, meaning I can't shake the **** out of it.

I've gotta have the car up on jackstands today anyway for an oil change.. I'll take a look again at the mounts. Can you tighten them from the bottom or the top? Hard to tell just by looking under the hood.

 

You can get upgraded mounts from Mazdacomp. $20.00 each, $10.00 each for the Y block tranny mounts. Made a huge difference in the feel of the car. Shifter does not move around any more.

Todd

I wrote a review in the parts review section

 

You shouldn't have to tighten anything unless the previous install job was crappy. You can try using a pry bar and see how much free-play it has; sometimes it can even reveal a broken mt as it did mine. The replaced broken tranny mt made a world of a difference in my previous automatic rex, for the way it idled and shifted. Now, I just drive conservatively overly bumps and railroad tracks.

 

I've got the mazda comp motor mounts, they are great. $22.75 each

do you have to pull the tranny out to do those y ones? I was planing on doing them next month.

 

whats mazdacomps url?

 

Update: The driver's side mount was maybe 1/4 turn loose. I torqued both down for g/p and checked the trans mount - it was good. It didn't totally fix the shaking problem tho. Think I'm gonna go with a RB torque brace and be done with it.

Jim

 

Mazdacomps URL is: Mazdamotorsports.com
The mounts are classified as competition parts so you don't have to be a "racer / member" to get them.

Todd

 

HOW do you find anything on mazdamotorsports.com ? They don't have motor mounts for my 86 listed anywhere! I go and do a search and NOTHING am I doing the wrong type of search here?

 

just phone them. not listed.

 

maybe they are worn out

 

Is the "Y block" tranny mounts same as the tranny crossmember?

Isn't there only the 1 crossmember mount, and then mounting to the engine for the tranny ? or are there some hidden mounts that are hard to find? Book only shows the crossmember.. So what is this "Y block" mounts ?
Thank you

 

Anyone know if the Y block mount is the same as the crossmember? or a part of it? or what ?