[135]

my 92 xj makes a thump when i start it, shut it off, or every now and then when I hit a bump. sounds like is it coming from the front left of the jeep. I am wondering how I would go about checking my motor mounts with a manual tranny. i know with an auto, you can put it in gear and watch how much the engine moves. How would I do this with a manual? I have no one around here most of the time to help me, so I am gonna have to be able to check it myself. Also, if it is the motor mounts, how hard are they to replace? My haynes manual says to jack up the motor, take the bolts out, and put the new mounts back in and put the bolts back in. but is it really that easy? I have always had trouble lining things up when working with motor mounts...is this a problem here? thanks for the advice, Ben

 

[2661]

One suggestion would be, put the emergency brake on start your rig jump out and take a look to see how much your engine is jumping around. If ya don't have an emergency brake that works, just block your tires. I had an 87 XJ in which I replaced the engine, and both mounts were busted. You can tell almost by just looking at them if there busted or not, I wish I had a pic. for you but I don't. If you can get a good look at the mounts, see how worn the rubber is. If ya got some big cracks in them, you know it's time to change them. Like I said, I've only done this with the engine completely out.

 

[3946]

I have two suggestions: first do a good visual inspection, if they are really bad it will be easy to see, if that is inconclusive, than chock the wheels and put a jack under the oil pan with a large flat board big enough to cover the bottom of the oil pan and jack up the engine until it tops out the driver side mount. If the mount is bad it should be very easy to see like this. Good luck!
NOTE: The driver side is the one that is most likely bad because that is the side that rises when the engine torques.

 

[135]

thanks for the ideas guys. I did start the jeep and go out and give it gas with the thottle cable while i watched the motor move, but it didn't seem to move much at all...what else could be causing this problem? I will jack it up and check with the jack when i get a chance, hopefully this weekend....Ben

 

[3946]

Look for a loose battery mount or anything else that could be loose in the engine compartment.