New Owner Question RE Motor mounts

[e9coupeguy]

So, i've driven the car for approx 600 miles over the last 2 weeks which is a ton for me but i cant help it... i love the car. Anyway, when i pulled into the driveway tonight i heard a faint but easily noticeable rattling from the engine bay / tranny. I guessed that it was transmission related as i have a similar sound in my 73 coupe thats a result of the noisy throw out bearings the old getrag 5speed trannys had (and partly due to some bushings that need to be replaced). Sure enough, when i depressed the clutch, the sound went away. Also noticed that when i turned the car off, there was a very obvious shudder that wasnt there before... almost like a diesel shudder if you know what i mean. I started the car back up and turned it off again with the clutch depressed and the shudder subsided some but was still there. Now, i dont wanna sound like a paranoid owner, but all the talk i've heard about loose engine mount bolts and sheared mounts has got me a little concerned since i know the shudder and rattle can also be a sign of failing mounts and a misaligned transmission. First question then is, are the motor mount bolt issues specific to the m models or all e85/86s? And, i've heard that there was a service bulletin issued by bmw for the motor mount bolts, but when i talked to the service tech at my local bimmer dealer (stopped through last week just to talk to them about an extended service agreement) and mentioned the bulletin, he acted as though it was a non issue and there was no official bulletin issued. Whats the official word on this? is it something they should be obligated to look at if i mention it? i dont wanna get the typical 'everything you are describing is normal' response from them.

Again, i dont want to sound paranoid.. i just know the sounds were absolutely not there before tonight and the fact that they are so obvious now has me a little concerned. The tranny rattle at idle was loud enough that i could hear it despite the fact the radio was on. Before tonight, the car was 100% quiet and smooth at idle with no odd habits at shut off. If it was brand new it might be something i'd attribute to the break-in process, but the car has 12500+ miles on it... i'd assume that it would be sufficiently broken in by now and that you wouldnt see huge changes from one day to the next. Anyway...

Thoughts?

Thanks in advance...

[PatJags156]

I have the same shutter when I turn off my engine too. I'm very curious as to what causes this..

[SCHMOUPE]

Originally Posted by PatJags156

I have the same shutter when I turn off my engine too. I'm very curious as to what causes this..

try shutting off the engine with the clutch in!

[franco209]

Originally Posted by shakib

try shutting off the engine with the clutch in!

What's the reason behind clutch in?

[e9coupeguy]

Originally Posted by franco209

What's the reason behind clutch in?

i state in the post that i shut it off with the clutch in. the issue i'm finding after today is that sometimes it does it, sometimes it doesnt. sometimes the 'clutch chatter' is there, sometimes its not. Sometimes the knocking is there, sometimes its not. I paid attention today to the driving conditions under which the above symptoms occurred and there was no pattern. the incidents were all random. didnt seem to matter whether the car was cold or up to operating temps. It just seems odd to me because usual or typical tranny sounds should be consistent. they may be louder or softer depending on operating temps, but they shouldnt just randomly pop up. The intensity of the sound varies literally from stoplight to stoplight. One second the car is idling perfectly smooth (clutch out) and quiet. the next time i stop, its rattling around like something is loose. Odd. i guess i'll see what BMW has to say, although i think i already know what it will be...

[BTM]

Originally Posted by shakib

try shutting off the engine with the clutch in!

For clarification, do you mean clutch engaged (pedal up) or clutch disengaged (pedal down)

I shut my car off in neutral with the clutch "engaged" (to nothing of course) and I get a shudder. Seems like normal driveline noise to me considering how much this car's drivetrain likes to "talk"

[vachss]

T.O. bearing clatter is endemic to all Z4s. It's annoying, but nothing to worry about.

[XMetal]

Originally Posted by BTM

For clarification, do you mean clutch engaged (pedal up) or clutch disengaged (pedal down)

I shut my car off in neutral with the clutch "engaged" (to nothing of course) and I get a shudder. Seems like normal driveline noise to me considering how much this car's drivetrain likes to "talk"

Shutting off the car with the clutch "disengaged" (pedal down) - even when it's not in gear, should make the shudder go away.

[imz4n]

Motor mount issues are for ///M cars only

[imom]

lightweight flywheel and M cars are known for the shuttering sound when you start or turn off the engine. I was told this is a BMW characteristic just like brake dust on the wheels...no one likes it...but we appreciate the other benefits of these cars.

[G80indy]

by the way the motor mounts bulletin applies to M cars only...

[wassup61]

I had the same problem, pretty soon it will vibrate through the shifter, then at idle only when warm. I have taken mine in and awaiting word. It is possible that its just gear rollover, but also might be a broken flywheel (the 2 masses seperated)

[e9coupeguy]

Originally Posted by 330indy

by the way the motor mounts bulletin applies to M cars only...

Thanks for confirming this. I wasnt sure whether it was just MCs or all Zs. One less thing to worry about.

It seems the problem is less noticeable (the inconsistent shudder at idle) since my last fuel stop. This makes me think the odd rough condition might have been due to a crap tank of gas. The previous tank I fueled up with 89 octane but at some stations in the city they arent always honest about what they are selling. Put 93 in this go'round and it 'seems' to be smoother.

I can live with the shudder at shut-off. Just wanted to be sure it was a typical issue.

Thanks for all of the responses!

[wassup61]

Originally Posted by e9coupeguy

Thanks for confirming this. I wasnt sure whether it was just MCs or all Zs. One less thing to worry about.

It seems the problem is less noticeable (the inconsistent shudder at idle) since my last fuel stop. This makes me think the odd rough condition might have been due to a crap tank of gas. The previous tank I fueled up with 89 octane but at some stations in the city they arent always honest about what they are selling. Put 93 in this go'round and it 'seems' to be smoother.

I can live with the shudder at shut-off. Just wanted to be sure it was a typical issue.

Thanks for all of the responses!

Read my post, its inconsistent now but will get worse and worse. I will let you know what the dealer says about mine.

[imom]

89 Octane? Holy crap... even my old Toyota Tacoma truck, I always filled mine up with Premium gas... If your car is an M or not...especially in California... I always put Premium gas in my car. You might want to try some techron in the gas tank.

[e9coupeguy]

Originally Posted by imom

89 Octane? Holy crap... even my old Toyota Tacoma truck, I always filled mine up with Premium gas... If your car is an M or not...especially in California... I always put Premium gas in my car. You might want to try some techron in the gas tank.

yeah. wasnt thinking when i did it. i've been driving my beater 4runner all winter and i always fill it with 89. reflex i guess. My mazda only took premium and thats all i put in the other two bimmers. Definitely wont happen again.