540i Engine Shudder/Vibrations

[chiefcorey]

I just purchased a beautiful 1995 540i with the V8. I had it inspected and the car appeared to be in great shape. It currently has 200,000KMs.

Here's the problem. The car vibrates. At all speeds, at idle, on the highway, around town. But not all the time.

The thing is that it doesn't happen all the time. Only about half the time. The rest of the time it runs smooth.

help me understand what this could be. I'm hoping that it's something as simple as an engine mount and not something wrong with the engine itself.

I should also note that the compression check came out okay and the car otherwise seems to have all it's power and runs well.

I did put new tires on it the other day, but the issue is the same after as it was before.

Please help.

[BillionPa]

welcome to the M60 earthquake on wheels.

you need new engine mounts.

they are NOT simple to change.

[95-540iLE]

I had mine changed last week. I watched the tech guy do it and it took 30 mins to 40 at tops. With the proper tools, it seemed quite straightforward.


welcome to the M60 earthquake on wheels.

you need new engine mounts.

they are NOT simple to change.

[BIGRED]

Our 530it does it as well. I am thinking it is tempurature related and if so maybe the fan clutch.

Don

[Fetch]

What sort of vibrations are caused by the bad mounts?

If it's a 'slow' rocking and not a 'cell phone' type vibration, then I get this sitting at idle, I wouldn't be surprised if the mounts were going on mine, I'll have to keep an eye on that/take a look at the mounts if accessible.

[stargazer_61]

I agree with BillionPa. Change the engine mounts and the transmission mounts while you are at it. Huge difference once changed. Also check for leaks in your power steering lines, as the fluid will destroy the mounts.

Do a search for replacement procedure. It is not easy but with the right tools you can DIY in less than two hours.

[chiefcorey]

What sort of vibrations are caused by the bad mounts?

If it's a 'slow' rocking and not a 'cell phone' type vibration, then I get this sitting at idle, I wouldn't be surprised if the mounts were going on mine, I'll have to keep an eye on that/take a look at the mounts if accessible.


The vibrations I get is like a rumble.... except it doesn't just do it when idling. At first I thought it was happening because it was idling pretty low, around 600rpm or less. But it kept up as I drove around. Then it went away, then it came back.

I've spent some time trying to figure out what brings it on, and what makes it go away, but to no avail.

I'm going to get the engine mounts checked out an hopefully that gives me a super smooth ride.

[stargazer_61]

If you want to see if the engine mounts are broken, try this:

1) Start the car & set the hand brake and let it warm up.
2) Open the hood
3) Find the throttle cable & push/pull it to rev the engine. Don't be shy about revving it hard.

If the engine mounts are shot, the engine will lift up on the left side at least an inch. It is not easy to tell if the mounts are shot simply by looking at them. On a LHD car, the driver side mount is buried underneath oil & power steering lines and is difficult to look at.

[BillionPa]

aaaaaaaaaaaaaaaaaaaactually....

if you have an automatic, dont rev it in park or neutral, as this can cause catostrophic damage to the transmission.

[Fetch]

aaaaaaaaaaaaaaaaaaaactually....

if you have an automatic, dont rev it in park or neutral, as this can cause catostrophic damage to the transmission.


So while you are in Drive, with the hood open, have a friend stand on the fender of the car while you accelerate at full throttle?

[632 Regal]

sounds like a great way of getting into the darwin awards for 06

So while you are in Drive, with the hood open, have a friend stand on the fender of the car while you accelerate at full throttle?

[BillionPa]

haha thats awesome fetch, i would love to see somebody do that.... as long as they didnt get smashed to bits.

the only way you would want to do the shake test on an M60 engine automatic is by putting it on a dyno.

there is a technical service bulletin in regards to failing valve bodies in the transmission, as they attempt to compensate for something that isnt going to happen (since the car is in neutral)

and dont jack the car up and run it like that, as its very bad for the rear CV joints, and the change in rotating mass can cause the car to push the jacks around.

[mattyb]

engine mounts are not hard at all, same for tranny mounts.

[stargazer_61]

aaaaaaaaaaaaaaaaaaaactually....

if you have an automatic, dont rev it in park or neutral, as this can cause catostrophic damage to the transmission.

Wellllll.........

I didn't mean it like he was going to let it rev for a half-hour or something. Just to see if the engine rocks in the bay. :)

[Vanguard]

if you have an automatic, dont rev it in park or neutral, as this can cause catostrophic damage to the transmission.

Why would this cause transmission damage?

[632 Regal]

because the drums arent drilled to release the fluid and when you spin it up in neutral or park all the clutches engage and *Poof*
Why would this cause transmission damage?

[Vanguard]

Good to know. Thanks.

[chiefcorey]

It seems the consensus is that this is a result of the Engine/transmission mounts.
I'll get them replaced tell you all what happened. Thanks!!!!:D

[genphreak]

Good to know. Thanks.Check the rear end too. Whenever engine mounts go it can be 2 root causes;

1) Wear
2) Abuse
or heh, Wear and abuse

Now be sure to check the rear end and drive train. Do you know that some hat wearing kid hasn't taken it drifting? If it's possible, next time you jack up the rear and check out all the mounts for cracking or damage. Look for bits of rubber apat around into crannies within the wheel arches...

Theoretically you could be up for centre bearing, (guibo if it has one), rear subframe mounts and shock mounts when you next do the shocks.

:) Nick

[BIGRED]

Our varying engine vibration was caused most likely by the fan or fan clutch. I say most likely because I changed the fan, the clutch, belt tension pulley's and shocks.

To track it down I started up the engine (when it was dead cold) without the fan or belt on and there was zero vibration (total run time 10 seconds)

I lean towards the fan or the clutch because it makes sense to me that as the temp changes the fan would act differently.

Perfectly smooth now.

Good luck
Don

[Chris'91'525i]

If you want to see if the engine mounts are broken, try this:

1) Start the car & set the hand brake and let it warm up.
2) Open the hood
3) Find the throttle cable & push/pull it to rev the engine. Don't be shy about revving it hard.

If the engine mounts are shot, the engine will lift up on the left side at least an inch. It is not easy to tell if the mounts are shot simply by looking at them. On a LHD car, the driver side mount is buried underneath oil & power steering lines and is difficult to look at.

We would check for bad motor mounts by;
Giving the car some gas while it's in gear with your foot on the brakes. No need to Rev motor up.
The motors torque will lift the motor right off the bad mount.

[Podmore]

aaaaaactually ...... revving in Park or Neutral won't have any effect on the trans as the only thing spinning is the gearbox input shaft, no load on the gears at all (Park locks the output shaft). You need to load the drive train, so with the trans in Drive but foot firmly on the foot brake and handbrake on, give the throttle a few sharp blips - no Italian tune-up style hit-the-rev-limiter mashing of the foot to the firewall - and have your friend (who shall be standing beside, not in front, of the car) watch for excessive movement in the engine ..... sheesh, you guys!

[Morgenster]

Hmm. Is it really an inch? I think I get about an inch of movement just by revving my M50 in neutral on the manual trans. Could be the motor mounts are kinda shot but it's not that big a deal vibration-wise.

[632 Regal]

aaaaaaaaaaactually the auto transmisions can and do fry with free reving due to the spinning drum (& clutch packs) as I mentioned earlier.


aaaaaactually ...... revving in Park or Neutral won't have any effect on the trans as the only thing spinning is the gearbox input shaft, no load on the gears at all (Park locks the output shaft)