brianc
12-17-2007, 09:32 PM
It's not as trivial as it seems if you just go from your service manual. I had two service manuals, the pelican manual, and several posts from these forums. I had a few things come up that were not discussed in any of the above.
1. Removed the bottom nuts for the engine mounts. They were 17mm on my 98 M3/4. You can access the nuts through a hole in the control arms using a 6" extension - it gives you a straight shot at the nut. The passenger side needed a deep socket. A normal socket would get stuck underneath a frame section so that I could not back out the bolt (because the back side of the socket would get lodged in between). With the longer socket I could force the socket body alongside the frame section. Don't use an impact socket - it won't fit. You'll see what I mean when you're under there.
http://www.alphazone1.com/pics/engine_mount2.jpg
http://www.alphazone1.com/pics/engine_mount1.jpg
2. Remove the top engine mounts nuts. They're also 17mm. As I saw in other posts the 10" wobble extension is the key. Pick one up at Pep Boys, Autozone, Sears etc... Use it along with a second 10" extension to get to the top engine mount nuts. It's very easy. I used 3/8 drive.
3. The engine needed to be lifted about 2.5" to allow clearance to remove the old mounts. I found I needed to temporarily remove several components to allow the engine to move this much. Many of these steps were not mentioned in the service manual or other posts. I had to disconnect or remove the following parts...
- The hose clamp attaching the end of the tube connecting air mass meter to intake manifold. The one closer to the front of the car. Then remove the tube from the air mass meter so that when the engine is lifted the part is not ripped (since the air mass meter is connected to the engine bay - not the engine).
http://www.alphazone1.com/pics/engine_hose.jpg
- Loosen both sides of nuts from the transmission mounts. I mean not just left and right sides but the top & bottom nuts as well. Do not remove them all the way though just loosen them as much as possible to allow the engine/transmission to shift when you lift the engine. I made the mistake of removing the bottom nuts ony and not the top ones. When I got done replacing the engine mounts the transmission became totally misaligned because I took the nuts out completely and allowed the transmission to completely misalign from the mounts.
- Remove the covering that goes over the top of the radiator. I'm talking about that black plastic piece that goes over the radiator and the whole front center part of the engine bay. It's held in with 4 screws and 2 rivots.
- Remove center engine cover (allows room for engine to lift enough without hitting top/back engine area near the firewall).
http://www.alphazone1.com/pics/engine_room1.jpg
- Clip out the center grille section at the base of the windshield. There's 3 clips holding it in. You may need to remove the center rubber moulding first.
- After removing the grille section you can see the two screws that hold in the center housing that contains all the wires running accross the rear of the engine bay (just in front of the firewall). Remove those two screws so that you can manouvre that part around to allow the engine to lift enough.
http://www.alphazone1.com/pics/grille_windshield.jpg
- Place a 2x4 under the oil pan to distribute the load while jacking up the engine. I needed to put the jack 2/3rds the way to the left of the oil pan area to balance the engine a bit so it would lift both left and right sides close to evenly. It still was heavier on the passenger side as the mass of the engine block is offset versus the oil pan area. The piece of 2x4 I cut was about 18" long.
http://www.alphazone1.com/pics/engine_lift1.jpg
- Slowly lift the engine. KEEP A CLOSE EYE on the power steering houses. The intake hose and the one going to the coiling coil are both attached to the chassis so as you lift the engine the power steering fill resevoir is attached to the engine so those hoses get strained. They have no extra lenght. I HAD to remove both hoses from the fluid resevoir or else that would have broke. Thus I had to replace the power steering fluid (about 1.2 quarts).
http://www.alphazone1.com/pics/steering_hoses.jpg
- Also as you lift the engine you will notice the primary cooling fan blade will hit the shroud as you lift the engine since the fan is attached to the engine and the shroud is fixed to the frame. I had to gently manouvre the fan so it would pass in front of the shroud and stick out about 1/2" above it. I could not ge the engine mounts out without raising the engine to the point where the fan blade stuck out a bit over the shroud.
- When there's enough room replace both engine mounts and align the new ones properly.
- Slowly release the jack while checking the seating of the engine mounts. Also keep an idea on the tranmission mounts to make sure they are also seating properly.
- Now you can tighten the nuts for the new engine mounts and transmission mounts. Then put everything else back together.
- Before putting the covering over the radiator make sure everything is aligned properly and that the radiator, shroud and fan are aligned properly. If everything seats back down correctly the fan will have enough room to move between the shroud and the radiator. I always pay particular attention to this area since the shroud and the radiator mounting system is so flimsy it is easy to get misalinged - and you don't want the fan taking off, hitting stuff, and detroying your radiator, housing, hoses, etc..
For me it did not end up being an easy job. It took me about 3 hours. I always take my time and take small breaks and look at things two or three times. I know a lot of people seem to not have to take out nearly as many things as I did but I definitely had to take out all the things I listed above in order to allow clearance to lift the engine.
My old mounts didn't look too bad. Maybe a little hard & worn out. I was wondering if it was necessary. I replaced them as a wear item at 120k, not because I was experiencing any particular vibration or problem. When I went to work this morning I was shocked. It's hard to explain but the car seemed smoother and lighter. Dead serious, it was the same feeling as if you take 200lbs out of the car. Weird. Even the trasmission seemed smoother. This is not placebo effect ;) I know my car extremely well - this was definitely a noticeable change.
1. Removed the bottom nuts for the engine mounts. They were 17mm on my 98 M3/4. You can access the nuts through a hole in the control arms using a 6" extension - it gives you a straight shot at the nut. The passenger side needed a deep socket. A normal socket would get stuck underneath a frame section so that I could not back out the bolt (because the back side of the socket would get lodged in between). With the longer socket I could force the socket body alongside the frame section. Don't use an impact socket - it won't fit. You'll see what I mean when you're under there.
http://www.alphazone1.com/pics/engine_mount2.jpg
http://www.alphazone1.com/pics/engine_mount1.jpg
2. Remove the top engine mounts nuts. They're also 17mm. As I saw in other posts the 10" wobble extension is the key. Pick one up at Pep Boys, Autozone, Sears etc... Use it along with a second 10" extension to get to the top engine mount nuts. It's very easy. I used 3/8 drive.
3. The engine needed to be lifted about 2.5" to allow clearance to remove the old mounts. I found I needed to temporarily remove several components to allow the engine to move this much. Many of these steps were not mentioned in the service manual or other posts. I had to disconnect or remove the following parts...
- The hose clamp attaching the end of the tube connecting air mass meter to intake manifold. The one closer to the front of the car. Then remove the tube from the air mass meter so that when the engine is lifted the part is not ripped (since the air mass meter is connected to the engine bay - not the engine).
http://www.alphazone1.com/pics/engine_hose.jpg
- Loosen both sides of nuts from the transmission mounts. I mean not just left and right sides but the top & bottom nuts as well. Do not remove them all the way though just loosen them as much as possible to allow the engine/transmission to shift when you lift the engine. I made the mistake of removing the bottom nuts ony and not the top ones. When I got done replacing the engine mounts the transmission became totally misaligned because I took the nuts out completely and allowed the transmission to completely misalign from the mounts.
- Remove the covering that goes over the top of the radiator. I'm talking about that black plastic piece that goes over the radiator and the whole front center part of the engine bay. It's held in with 4 screws and 2 rivots.
- Remove center engine cover (allows room for engine to lift enough without hitting top/back engine area near the firewall).
http://www.alphazone1.com/pics/engine_room1.jpg
- Clip out the center grille section at the base of the windshield. There's 3 clips holding it in. You may need to remove the center rubber moulding first.
- After removing the grille section you can see the two screws that hold in the center housing that contains all the wires running accross the rear of the engine bay (just in front of the firewall). Remove those two screws so that you can manouvre that part around to allow the engine to lift enough.
http://www.alphazone1.com/pics/grille_windshield.jpg
- Place a 2x4 under the oil pan to distribute the load while jacking up the engine. I needed to put the jack 2/3rds the way to the left of the oil pan area to balance the engine a bit so it would lift both left and right sides close to evenly. It still was heavier on the passenger side as the mass of the engine block is offset versus the oil pan area. The piece of 2x4 I cut was about 18" long.
http://www.alphazone1.com/pics/engine_lift1.jpg
- Slowly lift the engine. KEEP A CLOSE EYE on the power steering houses. The intake hose and the one going to the coiling coil are both attached to the chassis so as you lift the engine the power steering fill resevoir is attached to the engine so those hoses get strained. They have no extra lenght. I HAD to remove both hoses from the fluid resevoir or else that would have broke. Thus I had to replace the power steering fluid (about 1.2 quarts).
http://www.alphazone1.com/pics/steering_hoses.jpg
- Also as you lift the engine you will notice the primary cooling fan blade will hit the shroud as you lift the engine since the fan is attached to the engine and the shroud is fixed to the frame. I had to gently manouvre the fan so it would pass in front of the shroud and stick out about 1/2" above it. I could not ge the engine mounts out without raising the engine to the point where the fan blade stuck out a bit over the shroud.
- When there's enough room replace both engine mounts and align the new ones properly.
- Slowly release the jack while checking the seating of the engine mounts. Also keep an idea on the tranmission mounts to make sure they are also seating properly.
- Now you can tighten the nuts for the new engine mounts and transmission mounts. Then put everything else back together.
- Before putting the covering over the radiator make sure everything is aligned properly and that the radiator, shroud and fan are aligned properly. If everything seats back down correctly the fan will have enough room to move between the shroud and the radiator. I always pay particular attention to this area since the shroud and the radiator mounting system is so flimsy it is easy to get misalinged - and you don't want the fan taking off, hitting stuff, and detroying your radiator, housing, hoses, etc..
For me it did not end up being an easy job. It took me about 3 hours. I always take my time and take small breaks and look at things two or three times. I know a lot of people seem to not have to take out nearly as many things as I did but I definitely had to take out all the things I listed above in order to allow clearance to lift the engine.
My old mounts didn't look too bad. Maybe a little hard & worn out. I was wondering if it was necessary. I replaced them as a wear item at 120k, not because I was experiencing any particular vibration or problem. When I went to work this morning I was shocked. It's hard to explain but the car seemed smoother and lighter. Dead serious, it was the same feeling as if you take 200lbs out of the car. Weird. Even the trasmission seemed smoother. This is not placebo effect ;) I know my car extremely well - this was definitely a noticeable change.