Hi guys, I have a stock 99 cherokee, and when I am starting off I hear a rumble noise coming from what it sounds like is just under the firewall. I have been reading up on this, and from what I am reading, it could either be a tranny, or motor mount? I am wondering what I could do to check to see if its the problem, or if it is even the problem? I appreciate the time you guys put into the forum. Been a wealth of knowledge to me over the years. Thanks!

 

Also to add, I have looked under the hood at fans and everything seems to be in order.

 

do you feel any vibration anywhere when it makes that noise?

 

I can feel a bit of vibration from the floorboards yes. That may be why Im thinking its some sort of mount?

 

Check your motor mounts and trans mount.
Look here also:

 

The cheap and simple trick to check for a bad tranny mount is to stick a large screwdriver or pry-bar between the tranny case and a frame rail and see if you can move the tranny at all. Gently attempt to shift the tranny side to side/up and down. If it moves you definitely need a new tranny mount.
If you do replace the tranny mount do NOT use Anchor brand - OEM is best but NAPA driveline has been reputed to be a decent replacement.
If your tranny mount has never been replaced, it's more than past due for a new one.

 

It would be nice if all problems could be that straight forward.