Northstar Engines and System Technical Discussion Discussion, Motor Rocks in Cadillac Engine Technical Discussion; I have a 97 STS w/ 200,000 miles the motor moves quite a bit when I rev it, or when ...
you said you replaced your front lower mount. how hard was it to replace? I gotta do mine, when i put my car under load while holding the brake the front of the motor lifts up about 3 or 4 inches, i think its only held down by the torque arms.
but what do you have to do to replace the front one?
The Front Mount is a pain, only cause there is no access to the top motor mount bolts. The Bracket that connect the mount to the engine has to be removed.
But here's the easiest way I figured out how to do it with out taking out the radiator or cooling fans.
1) Jack the car up and support it on both sides with jack stand under the front frame rails or put it up on ramps, don't forget the emergency brake or wheel jocks n the rear wheels
2) unbolt all the bolts on the bottom of the mount, this includes both Trans mounts, left and right, and the motor mount
3) then unbolt both top strut mounts (dog bones)
4) remove the air cleaner box, its attached to both the motor and the body and if u jack the motor up without removing its gonna break the clips that hold it shut
5) Position a floor jack under the brace that covers the exhaust cross over from the mainfolds, its heavy steel and is bolted to both the engine and trans, its a good point to lift the motor from
6) JAck the motor as high as you can, once you meet resistance stop, the exhaust will move a bit but its ok most is taken up by the flex coupling before the cat.
7) under the hood the black steel bracket that connects the mount to the engine, is directly under the valve cover across from the cooling fans, its held in by two 15mm bolts.
8) under the car unbolt the bottom of the bracket, its held in with two studs that are tipped with reverse torx and have 15mm jam nuts on them. First loosen the jam nuts, then remove the studs I used a 1/4" 16 point socket on a 1/4 drive rachet, it worked well. Also remove the trans brace that connects the mount to the transmission.
9) With the bracket loose flip it around till up can get to the top bolts on the mount 15mm, I put the bracket it on its side. also Make a note how the mounts was attached, the mount is slanted on the bottom
10) now you can remove the old mount, I couldn't squeeze it out untill I lowered the motor down, but if your due for an oil change removing the oil filter will make it a whole lot easier.
11) Slip the New mount in, jack the motor back up, (Thread lock everything), Bolt it onto the bracket, attach the bottom of the bracket it first and the trans brace, bolt up the top of the bracket, Lower the motor, making sure all the mount bolts go into there holes. Bolt everything back up tight,the air cleaner, and the top strut mounts.
And that should be it, I would give it about an Hour from start to finish