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DIY: Motor Mount Replacement

80K views 44 replies 27 participants last post by  dirty vert 
#1 · (Edited)
I changed my motor mounts out this morning. It took 2 hours from jacking the car up to bringing it down. Following these tips, you should be able to do it in under 11/2 hours w/ no fuss. Probably a 3-out-of-10 difficulty. This is on my 2000 232it automatic w/ 240,000 miles.

-HIGHLY recommend an engine support bar. Makes the job much easier than jacking under the oil pan. I bought mine from Harbor Freight for less than $75 shipped.

1. Remove the MAF sensor and intake boot to get a better shot at the top of the driver's side top motor mount bolt.
2. Remove the air intake over the fan shroud and remove the two fan shroud fasteners (one Torx screw and one plastic fitting).
3. Install the engine support bar and tighten to relieve weight from motor mounts.
4. Remove top motor mount bolts from both sides. I used a 10" wobble extension, 6" wobble, and universal. It's a 16mm nut.

Here's a shot of the old passenger-side motor mount vs new. Pretty big difference!
 

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#2 · (Edited)
5. jack the engine up until the fan shroud is about 1/2" higher than normal.
6. get under the car and unbolt the passenger side mount bracket. There are 4 12mm bolts. MAKE SURE there isn't any weight on the motor mount from the engine. You should be able to see the engine lifted from the top.
7. remove the bottom 16mm nut from the pass side mount. A 1/2" drive and short socket easily fit w/o any extensions.
8. remove the old mount and install the new one. the heat shield tab on top of the mount aligns w/ a hole in the top of the mount. The bottom of the motor mount also has a tab that aligns w/ a hole in the frame bracket. Tighten the bottom nut, finger tight.
9. position the motor mount bracket back on the mount and tighten the 4 12mm bolts to the side of the engine. I believe it's 33ft/lbs.
10. Here's the trick that makes the driver's side a sinch. Tighten the passenger mount bottom bolt 1st. Then, from the top using extensions, tighten the passenger top nut. Tightening the nut rotates the engine just enough to give plenty of clearance on the driver's side.
 

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#3 ·
11. Remove the driver's side bottom nut. Should be plenty of room to remove the driver's side motor mount. Mine was totally shot and came out in two pieces spilling oil everywhere.
12. Install the new mount and tighten the bottom 16mm nut.
13. slowly lower the engine w/ the engine brace to lower the engine mount bracket onto the motor mount top stud.
14. Tighten the top nut and re-install the MAF and air intakes. mount the fan shroud back and you're done!

Using the engine brace, this is an easy job! I might have enough courage to tackle the leaky oil pan gasket next... maybe.
 

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#4 ·
Thanks for the write-up. I'm getting ready to do my mounts. Is this a good time to do the oil pan gasket? I have 130K miles on it and I think this is the only gasket I haven't replaced yet. I noticed a few oil drops on the garage floor and I already did the oil filter housing gasket last summer with the oil seperator.
 
#11 ·
Vibration only occurred while accelerating, and usually more in 1st and 2nd gear. I never noticed anything cruising, or downshifting.

I raised the engine 1/2 to 3/4". You can probably get away with a little less. I didn't notice any binding anywhere.
 
#14 ·
Bumping this to say thanks for the alternate instructions. At first I was a little skeptical as it deviated from the factory manuals.

However after doing it this way, there really is no need to take off your cabin filter and assembly as noted in the factory procedure and also loosening the fan shroud instead of removing the fan clutch makes more sense as well.

Here are some additional tips for those that have the facelifted models(mine was also an autotragic):

1. You can unclip the secondary air pump resorvoir off the bracket on the passenger side and swing it to the other side to have more working room for the top bolt on the passenger motor mount.

2. It was easier for me to remove the airbox assembly as well to get a better view of the driver's side mount.

3. No need to remove all 4 13mm bolts on the passenger motor mount bracket. If you remove 3 and just loosen the 4th one, that will allow you to move the bracket up and down to clear the motor mount top bolt. This will allow you align the bracket and insert the bolts more easily upon assembly.

4. Lube up the threaded engine support rod and washer that sits on the bar. This will make adjustments easier.

5. If you can't get the passenger's side top motor mount back on or you can't clear the driver's side bracket to get the old motor mount off, try turning the engine support brace handle a couple times, often times this will shift the engine slightly to the left or right allowing more clearance.

6. Taking the front wheels off will allow more elbow room to remove the bottom bolts on the engine mounts

7. If your OCD about your car's appearance, you might wanna put some masking tape where the feet of the engine brace comes in contact with the fender to prevent any scraping or scratches.

8. Get the M3 version mounts if you don't care about Caddilac comfort but still want a civil and refined "BMW" ride. Transitions and fast switchbacks seem more solid than before(don't know if it's new mounts, m3 mounts, or combination of both).

9. If you have an earlier car and it came with the oil pan access panel, remove it as you can snake your arm in there to gain more access to the mounts.
 
#16 ·
quick question for you all.. on my 328 when accelerating hard from 1st, when i push the clutch in to change to 2nd the gearstick wobbles like the engine is wobbling after dumping the clutch in..only does it at high revs.

would this be my engine mounts shot? i replaced the Gb mounts and guibo and no change.
 
#17 · (Edited)
Old thread, but I got some great information. I'm about to do mine. Thanks for posting all of this and taking the pics.

About your vibrations that are pronounced under heavy loads of torque being put to the ground (first and second gear being most obvious as they are lower). STOP hitting the car hard now, please. Otherwise you will further damage your subframe. Unless you have searched for subframe damage underneath the car and in the trunk, do it now. First check under the car, although there may be damage you can't see, hence the trunk section you will search next. Refer to number 8 of these directions. This is where you may have cracking going on.

These were my symptoms of two failing subframes.
 
#18 ·
I replaced my motor mounts this past weekend. Got the engine support at Harbor Freight for 59 bucks. Took me 1.5 hours to complete thanks to this writeup (even though I missed the part about tightening the exhaust side mount down to rotate the intake side up enough to put insert the mount - there was probably at least a 1 inch difference in the height of the old mount vs the new mount - I lifted the engine up about 6 inches to clear the intake side.) The only thing I broke was that weak nipple on the intake boot.

The car feels a lot more solid...now to tackle the rear diff mounts and a new steering rack...

btw, my e46 touring just rolled over 200k.
 
#20 ·
XI Specific Motor Mount - '05 325XI, MT

Thanks beberle ! Excellent Post!

(I'm posting to this older thread for easier searching - adding XI specific info)

I already had HF engine support bar, and I used it much as you suggested. The car was already jacked up to do CCV/CVV, lower intake boot, TB & AIC valve cleaning. I used the bar and hanger to elevate the engine - threads and top of hanger washer well greased, and about 6 complete turns after the initial compression of the support bar rubber. At 93K my right side (passenger) engine mount was dead - and the top mounting stud came out with the nut. Left side mount rubber had hardened, but it was not as compressed as some pictures I've seen.

Comments / added details for xi:

Skip Step 10, the tip on tightening the passenger side mount, While this will rotate the engine, on my car I think this would run high risk of ruining the new passenger (right) side mount. On rear drive cars I can't say.

1) Fasten support hook as illustrated by OP from front to avoid breaking CVV pipe to VC - I saw someone state that BMW says raise engine 5mm, but I went about 1 inch, watch for any interference;
2) Loosening the SAP from its mount avoids a possible problem;
3) I have a Manual, but for Auto trans consider removing engine fan / clutch; 4) For XI you will need to partly drop the sub frame. Loosen front sub frame bolts (2 turns or less is fine) and probably remove rear (shorter) sub frame bolts. These two pairs of bolts are recommended single use;
5) If XI suspension is fully assembled in good condition you will need to pry the rear of the sub frame down. I used a 1 3/8 inch flat bar to keep the left (driver) side corner of the sub frame dropped while I removed and replaced both mounts.
6) After installing mounts, lower engine onto them to torque nuts;
7) Lower the car to load suspension and sub frame, torque sub frame bolts to recommended spec (mine were 81 lb-ft by Bentley).

This turned out to be both easier and harder than I expected. It's very satisfying - the cleaned TB / AIC valve, new mounts, and recent struts/shocks have me feeling like I'm driving a new car. And my CVV system is probably good for another 100K.

Hope this helps other xi owners.

Mariner05
 
#23 · (Edited)
Engine mounts flange nut

Hello all! I was hoping someone could help me out here. In error, while changing the lower control arm on my 1999 323i sedan, we removed the driver side engine mount flange nut on top , before realizing that it was the wrong nut. So after locating the correct bushing nut on control arm, we went to replace the motor mount flange nut and realized it mysteriously disappeared. Can anyone tell me what size flange nut to buy, as I believe its 16 mm, but unsure of the thread size...any ideas?I bought one from local depot but incorrect threads. PLEASE HELP!:eek:
 
#24 · (Edited)
Hello all! I was hoping someone could help me out here. In error, while changing the lower control arm on my 1999 323i sedan, we removed the driver side engine mount flange nut on top , before realizing that it was the wrong nut. So after locating the correct bushing nut on control arm, we went to replace the motor mount flange nut and realized it mysteriously disappeared. Can anyone tell me what size flange nut to buy, as I believe its 16 mm, but unsure of the thread size...any ideas?I bought one from local depot but incorrect threads. PLEASE HELP!:eek:
The Bentley says it's a M10 bolt, and should be torqued to 33 ft-lb. Looks as though the nut has a flange.
Pretty sure its a course thread.
16 MM may be the head size, and actually is irrelevant if you're trying to find a replacement nut, you're only worried about the threads.
I wouldn't use the cheap ones like you see at Home Depot, you need a quality SAE/USS graded nut for something that critical, probably a Grade 5 would do, if you can't get to a dealership. It should have 3 dots stamped on the top of the nut.
 
#25 ·
If the nut 'mysteriously disappeared' and you have not moved the car, try a magnetic retrieval tool in the boxed area of the motor mount bracket. You may not need to purchase a new nut. I experienced a similar nut 'disappearance' when changing out motor mounts. I knew the nut was there - still took a while to get it back out.

Good luck !
 
#27 ·
Thanks

Hello, thanks for your help, but unfortunately we already moved it, went to home depot etc, and couldn't locate the nut...I believe I tossed it anticipating it was the nut from the control arm bushing and was replacing them anyway. I contacted local BMW dealer by me here in New York, and they said I can pick one up Saturday. It was suggested that I don't drive it too far until I replace that nut. Come to find out its a 10mm course thread. Anyone know why shocks in rear would rub on passenger side when going over bumps, they were replaced in 2013 just 5000 miles ago. You guys are great, thanks for your insight and knowledge.
 
#28 · (Edited)
Just a quick note for xi owners........
today I changed out the engine mounts on my 2003 325XI.
they are different from the ones in the photos by original poster, so don't be surprised when you get them and open them up.
ALSO, on the driver's side, you will have to loosen the lower control arm bolts at the rear to swing it out of the way, otherwise you won't have room to get the old one out and the new one in. the LCA has two bolts at the rear, and two at the front. I loosened the 2 at the front and removed the 2 at the rear. you will not have to completely remove the LCA
 
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