I am the owner of a 1999 STS, and i am looking for information on replacing the front motor mount. i was told by the dealer it was broken and want to know if this is something i can do myself considering i am pretty handy. anyone have any experience with this, diagrams, tips, suggestions'

thanks,

Not sure how "handy" you are, but the job is a PITA. I just did mine recently, and here is a rundown. Support the car on jackstands, behind the engine cradle. Remove the splash shield. Drain the radiator. Remove the radiator fans (basically to do this, you will need to disconnect everything from the radiator including all hoses and fittings), remove the radiator (gives you a few extra inches to work), put a jack, with a large heavy pice of lumber (like a 2x8) under the oil pan. remove the two lower motor mount bracket nuts/studs, remove the two upper motor mount bracket bolts, remove the lower engine mount nut, loosen the four rear most cradle mount bolts, remove the two forward mount bolts, you should be able to wiggle the bracket/mount assembly out. Change the mount. Reinstall everything. I did this job, at least half in the dark holding a flashlight, in about 5 hours. It would have gone much quicker, had I waited until the following morning. But, I got impatient. I wish you the best.

Don

ColoradoCaddie - I just did mine last week. First off make sure you check your upper radiator hose. Mine was damaged. The mount retails for about $130 from GM and based on the nature of the job I wouldn't even consider an aftermarket mount. If your car has over 100k miles on it (mine had 115K) you may want to do crank sensors and maybe even a radiator. Also check your lower hose. I also did cooling fans. Some people would only do the mount, but if you like your STS as much as I like mine it was a small price to pay. Don't forget distilled water when you fill your cooling system and crushed tablets in the upper hose. Good Luck. Let us know how it turns out.

Not sure how "handy" you are, but the job is a PITA. I just did mine recently, and here is a rundown. Support the car on jackstands, behind the engine cradle. Remove the splash shield. Drain the radiator. Remove the radiator fans (basically to do this, you will need to disconnect everything from the radiator including all hoses and fittings), remove the radiator (gives you a few extra inches to work), put a jack, with a large heavy pice of lumber (like a 2x8) under the oil pan. remove the two lower motor mount bracket nuts/studs, remove the two upper motor mount bracket bolts, remove the lower engine mount nut, loosen the four rear most cradle mount bolts, remove the two forward mount bolts, you should be able to wiggle the bracket/mount assembly out. Change the mount. Reinstall everything. I did this job, at least half in the dark holding a flashlight, in about 5 hours. It would have gone much quicker, had I waited until the following morning. But, I got impatient. I wish you the best.

Don

I think I have a mount thats broken or loose but I'm not for sure. I can tell when I hit it that something is definitly moving. Is there a way to tell with out taking it to the dealer. Based on what you just stated I think the car can hold off with normal driving until I get the parts ( sensors and etc..) If I have to do all of that I might as well replace somethings with the cradle already lowered. 97 STS 127k as of today

put the car in park pop the hood and pull the throttle cable if the engine jumps hard then you have a busted mount

Feel around the mount for cracks and oil. They're filled with oil and when they go, they can make a mess.

I think I have a mount thats broken or loose but I'm not for sure. I can tell when I hit it that something is definitly moving. Is there a way to tell with out taking it to the dealer. Based on what you just stated I think the car can hold off with normal driving until I get the parts ( sensors and etc..) If I have to do all of that I might as well replace somethings with the cradle already lowered. 97 STS 127k as of today
The only parts you can access. without doing the disassemble, are the lower mount bolt, which goes through the cradle, and the lower mount plate bolts (studs). Getting to the upper mount plate bolts will be very difficult (I found that one of mine was loose). And forget about the upper mount nut. As stated above, the mount is filled with oil. If you see signs of a heavy oil on the mount, then it definitely needs changing. My old mount wasn't leaking, so when I got it off the car, I cut it open to see what was in there. There is a heavy black oil, that stinks to high heaven. I am not sure what is worse, the oil in the mount, or gear oil. Good luck, hope everything goes okay for you.

Don

I replaced mine with only removing fans but also removed bracket and mount as one assembly if I remember correctly took about one hour had to put jack under motor to lift it slightly to remove as one assembly.I left radiator alone didn't have to mess with messy coolant.

I replaced mine with only removing fans but also removed bracket and mount as one assembly if I remember correctly took about one hour had to put jack under motor to lift it slightly to remove as one assembly.I left radiator alone didn't have to mess with messy coolant.
On my '02, there was no way to remove the fans, without disconnecting both radiator hoses, and the trans cooler lines. You got lucky on that one. I wasn't going to remove the radiator either. But, after the fans were out, it was just a matter of lifting it up. I am going to assume that something is different with our cars (maybe how the fans are made).

Don

I have a lift so it's pretty easy. My method doesn't involve removing any fans or anything but you do have to be able to lower the engine cradle, something you can't really do without a vehicle hoist.
From there you just remove the bracket that holds the mount and rotate the whole thing out, swap the new mount onto the bracket (but I think on that one the whole bracket comes with it) and put the thing back in.
A few minor things must be removed. It doesn't take long but we charge about 300 bucks labor here for that job... if you are lucky. Some guys charge more.
I'd think it would be a day project for a DIY and you probably would have to remove the fans.