Motor mount replacement interval?

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Motor mount replacement interval?

Post by songzunhuang »

My car feels rough at idle. It rattles the interior bits. I was wondering if the rubber of the motor mounts degrade (34 years old) like the rest of the rubber on the Car. My mounts are not broken or anything, but the rubber is probably hard after so many years.

So, how often do you all replace the mounts?

Is there a walkthrough somewhere our is it so easy that it’s not needed?

Thanks in advance for any info.
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Re: Motor mount replacement interval?

Post by bpoliakoff »

No scheduled replacement but after 30+ years the rubber is probably hardened. Unbolt each mount from the frame, 1 bolt each, and then use a floor jack with a wood block on it and place it under the oil pan. Jack until the motor comes off the mount and unbolt from the motor and then replace with the neew mounts. Shouldn't take 30 minutes. If available, buy a heavy duty replacement
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Re: Motor mount replacement interval?

Post by 86_6series »

I wouldn't jack up using the oil pan. Putting all that pressure on the oil pan gasket I think will squeeze

it and possible cause it to leak.

Just my $.02
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Re: Motor mount replacement interval?

Post by nick88highline »

I replaced mine after 30 odd years. Didn't make any difference to anything and it was a pig of a job which took hours. The trouble is that the rubber mounts get stuck in the engine mounting arms. I had to remove one of the mounting arms from the side of the engine to pull it out. This with the engine wobbling all over the place, and at one point it slipped to one side, was not easy job at all. Doing the transmission mounts was somewhat easier.
Worth doing for piece of mind though... :lol:
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Re: Motor mount replacement interval?

Post by songzunhuang »

nick88highline wrote: Mon Feb 12, 2018 2:06 pm I replaced mine after 30 odd years. Didn't make any difference to anything and it was a pig of a job which took hours. The trouble is that the rubber mounts get stuck in the engine mounting arms. I had to remove one of the mounting arms from the side of the engine to pull it out. This with the engine wobbling all over the place, and at one point it slipped to one side, was not easy job at all. Doing the transmission mounts was somewhat easier.
Worth doing for piece of mind though... :lol:
Thanks for the input. I'm still gathering input from the community before I embark on this (or not).
It doesn't look like a difficult job when I look at this, but looks can be deceiving...
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Re: Motor mount replacement interval?

Post by sansouci »

Song,
Did you already do the trans mount and the diff mount?
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Re: Motor mount replacement interval?

Post by hornhospital »

Advice from someone who's done it: Do the transmission mounts and engine mounts at the same time. Do ONE SIDE at a time. That way the engine mounts don't bind up like they will with the entire engine jacked up.
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Re: Motor mount replacement interval?

Post by songzunhuang »

sansouci wrote: Tue Feb 13, 2018 2:01 pm Song,
Did you already do the trans mount and the diff mount?
Nope, I haven't done any of the mounts. They don't look bad. I was just pondering...
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Re: Motor mount replacement interval?

Post by songzunhuang »

hornhospital wrote: Tue Feb 13, 2018 6:00 pm Advice from someone who's done it: Do the transmission mounts and engine mounts at the same time. Do ONE SIDE at a time. That way the engine mounts don't bind up like they will with the entire engine jacked up.
My car is an automatic. Same advice?
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Re: Motor mount replacement interval?

Post by hornhospital »

Since I've never changed mounts on an automatic E24, I don't know, but I'd guess yes. The mounts on both the engine and transmission are similar enough I doubt there'd be much difference.
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Time to replace the motor mount

Post by songzunhuang »

Well, I asked about this a few years back, but now I am sure that it's time to replace the motor mounts. Odd as I can run the car and use my hand to rev it and there is no visible movement at all in the area where I can see the hairline cracks on the motor mounts on both sides of the car.

Of course this is happening during the pandemic and it looks like no one has motor mounts in stock except the very pricey OEM ones.
Oh well, I guess it's not the worst thing in the world. I've got my next weekend's project.

It looks like my driver's side crack is slight.
Motor mount crack driver side.
Motor mount crack driver side.
DriverSide Hairline.png (1.07 MiB) Viewed 4000 times
The passenger side is more pronounced.
Motor mount crack passenger side.
Motor mount crack passenger side.
Passenderside Hairline crack.png (1.1 MiB) Viewed 4000 times
In any case, I'm doing them both. Maybe it'll somehow help with my vibration at idle as well. Fingers crossed.
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Re: Motor mount replacement interval?

Post by Rambler1963 »

Definitely time to replace those mounts. You could power brake the car and probably watch the motor try to jump out of the engine bay. As others have mentioned itd be good to do the transmission mounts at the same time if you haven't done so already. Also check condition if your center support bearing and flex disc.
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Re: Motor mount replacement interval?

Post by songzunhuang »

So this is annoying, I ordered OEM mounts from BMW for $270! I get a message a few days later saying that these are backordered until May and they cancel my order. OK, so I start looking at Pelican parts and other suppliers and I am wondering about something.

They have 2 different listings for motor mounts. One looks like my original OEM and costs almost $129 each.
https://www.pelicanparts.com/More_Info/ ... l0QAvD_BwE
$129 each
$129 each
OEM.png (204.79 KiB) Viewed 3907 times
The other is from Meyle, cylindrical and they are $15 each. How can that be?
https://www.pelicanparts.com/More_Info/ ... epHeader=Y
$15 each
$15 each
Cylinder.png (230.38 KiB) Viewed 3907 times
Can someone tell me if these are actually interchangeable?
Can they actually be so far apart in price and have similar function? I'm very skeptical.
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Re: Motor mount replacement interval?

Post by Ralph in Socal »

I've seen the cylindrical type on early series 1 cars. I have no idea if they work on later series 2 cars.

Good luck Song. Hope you're doing well

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Re: Motor mount replacement interval?

Post by 86_6series »

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Re: Motor mount replacement interval?

Post by 88m6 »

I have both on my M6 round one on drivers side, and pass side has hex shape one so they both fit.
Replaced passenger side as it was cracked now looking to do driver. Do have vibration at idle n power throttle which I have not experienced in any of prior e24’s I’ve owned. Tranny mounts were replaced many years ago with tranny rebuild.
I getting to old for this ](*,)
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Re: Motor mount replacement interval?

Post by songzunhuang »

I’ve read horror stories on the Ireland Engineering mounts. They seem to shear over time. As for Turner, they are all back ordered, except for the cylindrical ones.

There are a bunch of OEM types for sales from a company called Hamburg Tech, but once again the reviews on that are not so nice. So in the end, I was going to source original BMW mounts. It’s just proven difficult.
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Re: Motor mount replacement interval?

Post by hornhospital »

Hamburg Tech is the equivalent/may be the same outfit as Uro, which is most times garbage.

By the way, every time I see "Uro" I think urologist, someone I'm WAY too familiar with. =;
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Re: Motor mount replacement interval?

Post by 86_6series »

Hi Song,

Wasn't aware of the bad reviews. I bought these for my 265hp rebuild and so far all is good.

https://www.iemotorsport.com/product/ur ... s-e28-e24/
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Re: Motor mount replacement interval?

Post by songzunhuang »

hornhospital wrote: Mon Jan 24, 2022 4:01 am Hamburg Tech is the equivalent/may be the same outfit as Uro, which is most times garbage.

By the way, every time I see "Uro" I think urologist, someone I'm WAY too familiar with. =;
Before I knew better, I bought a bunch of URO parts. Every one of them have failed. I put "-URO" in every search now. Even things as simple as a hose doesn't work very long. Oh well, the supply chain problems are real. Two places I've placed orders for BMW OEM motor mounts and they cancel my order due to unavailability.

I am still wondering about the cylindrical mounts. It's says they work... wonder why the drastic shift in design.
Last edited by songzunhuang on Wed Jan 26, 2022 3:39 am, edited 1 time in total.
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Re: Motor mount replacement interval?

Post by hornhospital »

Simplicity of manufacture, most likely. That cylinder has to be easier to mold than the complicated trapezoid-shaped mount.
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Re: Motor mount replacement interval?

Post by Sbeaud »

Some info for the US M6 version - it shows the cylindrical one as the left side and the other as the right side. Pictures of mine below.

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1988 BMW M6 realoem motor mounts.JPG
1988 BMW M6 realoem motor mounts.JPG (47.57 KiB) Viewed 3801 times
1988 BMW M6 Left Side Motor Mount.JPG
1988 BMW M6 Left Side Motor Mount.JPG (129.61 KiB) Viewed 3801 times
1988 BMW M6 Right Side Motor Mount.JPG
1988 BMW M6 Right Side Motor Mount.JPG (151.71 KiB) Viewed 3801 times
1988 M6
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Re: Motor mount replacement interval?

Post by songzunhuang »

Interesting about the different mount on different sides.

Well, I am now three strikes on ordering BMW OEM motor mounts. BMW dealer, Pelican Parts, and eBay. What's annoying is that the last 2 listed many in stock, but when I ordered then, they cancelled my order after a few days saying that they don't have them in stock. I called Autohaus AZ and FCP Euro. Nothing. This is getting dire.

I started thinking about the cylindrical ones since it seemed impossible to get OEM standard ones.
Then I noticed Garagistic has these urethane cylindrical ones advertised. Guess what? Outta stock. What is going on?

My search continues. I have found one supplier that has a single one at $140, which is full retail. If I were to get this, I would still have to locate a second unit. What a pain.
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Re: Motor mount replacement interval?

Post by wattsmonkey »

Cylindrical one on passenger and driver's side of all cars I've owned except the M, and that had the reinforced metal one on rh side only. Different part number for M r/h mount as well, although it looks identical to reinforced ones in your picture.

cylindrical ones tend to look like The Cat in the Hat's hat after all that heat and (uneven?) weight on the right side, but left seems okay.

Have just amended above to remove reference to "driver's" and "passenger's" side!!!

Never noticed an improvement in vibration, per se, but the engine is very clearly located properly in the bay after replacement - fan blades no longer in danger of kissing the rad.
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Re: Motor mount replacement interval?

Post by Sbeaud »

Did some looking at motor mounts on Bring a Trailer sales. The US and Euro Ms seem to be visually the same as my pictures. Below are two 1987 US 635s. No telling whether the mounts are correctly fitted, but may be in indication of factory installation.

https://bringatrailer.com/listing/1987-bmw-635csi-36/
1987 BMW 635 Motor Mounts.JPG
1987 BMW 635 Motor Mounts.JPG (214.54 KiB) Viewed 3762 times
https://bringatrailer.com/listing/1987-bmw-635csi-34/
1987 BMW 635 Motor Mounts-1.JPG
1987 BMW 635 Motor Mounts-1.JPG (119.37 KiB) Viewed 3762 times
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