I can not get the bolt out all the way the motor mount bracket is in the way and won't come off HELP!!!!!

Assuming this is a XG 350, the process is lengthly.
1. Remove the RH radiator cooling fan (two 10mm bolts at the top & wiring harness connector to it).
2. Lift vehicle to remove the Right Front wheel (then remove 4 10mm bolts securing the plastic splash shield & remove it)
3. Loosen the 14mm nut on the alternator belt tensioner pully
4. Loosen the tension on the belt by rotating (counter-clockwise) the 14mm bolt at the bottom of the idler pully and remove the belt.
5. remove the pully & the idler pully (three 12 mm bolts)
6. Loosen the 14mm nuts at the top and bottom mounting points of the alternator.
7. Using a floor jack (or vehicle lift), support the engine using a jack-stand & 2x4 piece of wood under the oil pan.
8. This is tricky - lift the engine 'SLIGHTLY' to take pressure off the front engine mount - loosen the 17 mm nut on top of the mount itself and observe engine movement. If the engine moves upward 'slightly' remove the 17mm nut - if not, raise the engine slight more until you see the mounting bracket rise off the mount.
9. Remove the remaining 17mm nut (deep well socket), and two 17mm bolts and remove the engine mount bracket.
10. Here's another tricky step. Some 350's bottom Alternator bolt bores are 'SLOTTED'... some are NOT. You'll need to determine wether you'll need to REMOVE the lower bolt, or just loosen the mounting sleeve at the bottom bolt. If it's 'sleeved', I use an air hammer to loosen the sleeve. If it's not slotted, I remove the lower bolt (it's the only way to remove the alternator and pry it off).
11. At the top is an "L" bracket which uses two 12mm bolts to attach it to the engine (head). One of the two 12mm bolts is difficult to get to -- do your best to remove it because the battery cable to the alternator is in the way.
12. Disconnect the alternator wiring (battery cable & regulator harness connector)
13. Lift the engine as high as it will go & pry the alternator off its lower mounting.
14. manuver the alternator upward taking care not to damage the radiator.
15. Installation is in reverse order.
NOTE: If your XG's lower mounting point was slotted, your task is easy. If it isn't, your task now becomes more difficult as you must align the new alternator to facillitate re-insertion of the lower bolt.
PS If not slotted, I use a telliscoping magnet to help re-insert the lower bolt.

i'm in the same boat as you. this appears to be an exceptionally fun project! in order to remove the motor mount you need to make sure you have a engine hoist to support the load. perhaps you might be able use a good floor jack and try to support the motor from the bottom. In any case when the motor is propped and the load is balanced, the motor mount should be easy to remove -- just take out the 4 bolts. if however the weight of the motor is not sufficiently supported then it can truly be a nightmare to remove the mount. after removing the mount you can remove the other bracket and finally have access to the idler pulley!!

there are two bolts located behind the pully on the mounting bracket arm, (you have to use a 1/2 inch drive bar in the idler pully to move it so you can see the bolts) That will help you with locating the bolts, while you are moving the pully you might as well take the belt off to save time, After you remove the old idler pully install the new one, use your 1/2 drive bar on the pully to put your belt back on. Pretty simple job, good luck!

check the idler/tensioner pully's and the alternator pully, there is a common problem with one of these 3 going bad, usually an idler pully the best way to check is to get a mechanics stethescope and touch the end to the bolt on the idler pully's you will notice a very distinct sound difference from a smooth pully and one with bad bearings. gm tech here, seen many of these

Chilton's or, Mitchells books can Guide you through this repair; they are availible at autopart stores or online at; Chiltons.com or. Mitchellsonline.com

It would be called the engines accessory pulley mounting bracket

Hi once you have all the bolts off for the mount raise the front of the motor up till you can remove the center part of the mount
I use a floor jack and a 2x4 across the oil pan then remove the studs for the motor mount bracket now remove the bracket and now you can get the water pump out
hope this helps

that is not an idler pully that is the power steering pully if you feel through the holes in the pully you will feel the 13 mm head bolts that hold the pump to the block remove those bolts the pump will drop down and you can then remove the water pump also you have to remove the studs using the inverted torx end on the stud to unscrew it then the mount will come out

if thats got the 3800 or 3100 in it your taking out the wrong bolts!!!!!!!
your trying too remove the whole housing
you dont need too do that !!!
take off the 4- 10 mm bolts on the waterpump pully,then remove the bolts behind it i belive that there are 8 of them that takes the pump from the housing!!

No. Unfortunately for us 3800 owners, GM decided to put a bolt in that hole instead of a stud with a nut on the end. Yes, you are going to have to take off the motor mount along with the idler pulley bracket. Just make sure you don't put a cheap-o part on and you won't have to do it for another 15 years.