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Isn't this all typical drive-line clunk? My M coupes with 65, 100, and 130k miles all had it. In fact, even having ridden along with f50nuts 20kish mile coupe had it.
It used to worry me but I just stopped caring and started to shift more carefully. Depending how the clutch is released you can almost completely avoid hearing it.
I don't even
I just replaced my driveshaft with one from power train industries
Totally worth it amd great people to deal with.
Also to note the u-joints are staked, meaning not very many shops know how to replace them.
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The sucking sound is a vacuum being applied to your wallet, attempting to get some of your money to fix this issue...Originally Posted by tom h
Last edited by Kenn; 10-16-2012 at 12:03 PM. Reason: fixed quote html
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I have a '98 540i with the 6 speed and mine does the same thing. I had the guibo and center support bearing replaced roughly 7k miles ago so that can't be it. Does that mean the only thing left to change are the U joints basically meaning I need a new driveshaft?
Also, it has about 160,000 miles on it so would this be safe to assume about the ujoints and driveshaft replacement?
Last edited by killian665; 10-24-2012 at 07:32 AM. Reason: Automerged Doublepost
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If I shift mine at about 4,000 - no clunk? but then again I sometimes can shift it at 2,500 & no clunk! I'm a;most getting use to it.
Visit my Homepage, I have posted many pictures of some the motorcycles / cars I have owned & built over the years - http://www.picturetrail.com/tomhudson
B!tch Moan Whine
Mine clunks too when transitioning between on or off throttle. It also does it when shifting into gear from neutral. Also happens if I shift too slowly and clutch out after the rpms have dropped too much. I'm going to replace my flex disc, tranny mounts, and CSB this weekend and see if that helps. I'll also check out the u joints while I'm down there.
What are the chances of it being due to excessive gear lash in the diff?
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I'm no expert - matter of fact I don't know what I'm talking about on this matter or I would have fix it by now - The last BMW mechanic I went to said not to worry about it I was chasing ghost - my car only has 26K miles & it's a 2000 I would doubt it has excessive gear lash! No one has answered why my clunk comes & goes? If it were bad u-joints, bad flex plate, bad bearing I would think it would clunk all the time? – Mine doesn’t clunk all the time – I can go for a day without a clunk.
Last edited by tom h; 10-25-2012 at 03:33 PM.
Visit my Homepage, I have posted many pictures of some the motorcycles / cars I have owned & built over the years - http://www.picturetrail.com/tomhudson
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I was in a 2011 or 2012 GT Mustang today and heard a slight clunk. It sounds like it's just typical to hear some drivetrain noise, or maybe y'all are describing something louder?
"If the Corvette is a rebellious child of the extended automotive family, the M coupe is the blackest of sheep." - via Car & Driver
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my clunk is weird? almost like a sucking sound - somebody said it was BMW sucking dollars out of our pockets - I have a little over 29K miles on mine now & it hasn't got any worse - so I'm just going to live with it - it not real loud - i would prefer not to have it but it just might be the nature of the beast - My wife & I really do enjoy the car - I guess I'm getting use to the suck/clunk - Tom
Visit my Homepage, I have posted many pictures of some the motorcycles / cars I have owned & built over the years - http://www.picturetrail.com/tomhudson
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Back on the Island
Yes...drive shaft needs replaced. About $1500 at the stealership. I had mine done last year. Its a one piece unit...
"Racing is life. Anything that happens before or after...is just waiting." - Steve McQueen 1970
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Hi. My 1998 Z3 2.8L 124K miles, has the dreaded clunk, and one spot weld is broke on the cross member that holds the transmission mount. We raised the car and had some hold the brake and shift from forward to reverse and back many times while we looked for the clunk source. I noticed the differential moved up and down (vertical) as the gear was changed but the transmission mount is installed with the rubber's strongest support at a 45 degree angle to the direction of movement. Next week I'll be changing the flex disc, center bearing, and he transmission rear mount. I'm going to install the transmission mount with the strongest resistance to movement vertical. I think this will reduce but not eliminate the clunk.
It appears that the clunk on my car is caused when the automatic transmission occasionally shifts hard, and excessive gear lash in the differential. I'm going to attempt to shift the shims to close the gear lash. I may have the transmission rebuilt, maybe.
The lawsuit only applies to 1999 and later Z3s so BMW will not fix my 1998 model. Because my car has one busted weld I put 40 5/15 grade 8 bolts & grade 8 washers in the trunk floor along the spot-welds. see link
https://www.facebook.com/photo.php?f...type=3&theater
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Well, I hope that works out for you, but you took a panel with a known weakness and drilled it full of holes. Time will tell, I guess.
Interesting to note that your car has an automatic xmsn; I was beginning to think they were immune, not having ever seen a damaged trunkfloor in one myself.
In all honesty__and full disclosure__had I been faced with your circumstance, I would've only drilled out the one (1) broken spotweld and put a bolt through it. This would've left as much of the original panel/xmbr integrity intact, and might've been enough to thwart off the proliferation of spotwelds breaking (it's possible, based on newer data, that you only had one, or a few, suspect welds).
And please, consider using Metric bolts next time
Member
I had this problem. It was the automatic transmission ( GM 4L30E).
The good news is the transmission didn't need to be rebuilt LOL. The clutch plates showed very little wear and there was very little grime in the transmission. All it actually needed was two solenoids. The torque converter locking solenoid (clutch) , and the PMW band solenoid. I don't know what PMW means.
The transmissions through 2000 is a GM 4L30E and this is a common failure for it. Mine was shifting hard from 2nd to 3rd. I was told this is because the torque converter lock was staying engaged. The solenoids are easy to get to after removing the fluid sumps from the bottom of the transmission. You should buy your parts from Makco and you can change them yourself.
At this time everything is working good but I'm worried about getting parts in the future. Yesterday I searched the web for an engine rebuild kit to get a feel for parts availability. I couldn't find one.
Grumpy
BMW CCA Member
Hmmm, news to me. It's PWM, by the way. Pulse Width Modulation.
/.randy
Member
I wonder how many CSBs are changed without checking the U joints carefully, and how many are installed without the proper preload (10MM forward in the slot).
The OEM subframe and Diff bushings and trans mounts will let everything move around especially after some age. Also the splines in the two piece shaft will seize up over time and that puts a lot of strain on the driveline as everything moves around.
Some Diffs are set up with more backlash, its not from wear its setup from new. I have a 3.91 now with a lot more gear lash than the others sitting on the floor and I just use a heavier oil and it does not clunk at all. You have to know from feel what the proper gear lash feels like, but with good fluid there is barely any noticeable movement in the pinion shaft, it can be felt best dry.
So, if its Diff lash then live with it, try a heavier oil, or find one that is tighter. I think every Z3 should have poly sub mounts and stock diff ear bushing (to save the trunk floor) make sure your Motor mounts are good.
A loose diff can be made to clunk simply by easing the throttle back and forth under a light load, more noticeable I think in Auto trans cars shifting into gear.
Driveshaft and CSB issues will be different from that.
Member
i had the same issue. replaced guibo, center support and output seal..no difference...looked at the subframe bushings....not bad seem new...but then my mech hit me with it. he said my ring and pinion had about one inch play which caused a clunk and soft tranny mounts...now im in the process of fixing it..ill keep u updated
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I have some excessive gear lash in my differential but my clunk, or I should say wham was from the hard shift from 2nd to 3rd and that problem is fixed.
Now I have a new problem that I created. I did a compression test without removing the relay that kills the power to the spark plug coils. Big mistake. Now I have a rough idle. The engine makes a noise like whom, whom whom when idling. I'm think it's misfiring but not continuously. I don't have a dead cylinder or a noticeable loss of power when driving the car. I think the spark induced voltage in the wires that go to the coils coming from the ECU. I don't have a code reader but I will order one tomorrow. I think I ruined the ECU. I found several ECUs on Ebay for much less than $100 which isn't disturbing but I think the ECU must be programmed for my 1998 BMW Z3 2.8L at a BMW garage which will set me back considerably. Plz tell me I'm wrong.
It appears there isn't enough support for the differential so I'm adding additional mounts and running a brace to the existing differential mount bracket to keep it from cracking the sub frame cross member welds. Currently I have one spot weld broke loose. Not bad for 125,000 miles. A woman owned the car for the past ten years.
I put some bolts in when I thought the problem was the spot welds but I've seen more pictures and I see that the welds are just the tip of the iceberg. The differential mount bracket must be stabilized with a brace or the cracked metal will happen anyway. Click links to see bolt holes etc. I don't think the bolts were necessary. I believe all I needed to do was brace the differential mount bracket and the sub-frame cracking problem would be solved. I'll post some pictures when I finish.
https://www.facebook.com/photo.php?f...type=3&theater
https://www.facebook.com/photo.php?f...type=3&theater
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I think not caring is the key to happiness. I can drive my car like it is if I must.
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Last edited by DuWop; 06-09-2013 at 01:12 AM. Reason: additional information
Ralph
Wow.
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Yep, I screwed up
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I need to start a new thread for my problem because this is a clunk thread and not a whomp whomp whomp thread, but I'm new on the forum and I don't know how to start a new thread.
When the engine first starts it doesn't idle rough. When a engine first starts the air fuel ratio (AFR) is controlled by a map stored in the ECM and the idle RPM is higher until the engine warms up. The O2 sensor has heaters in it and isn't accurate until it warms up (600F as I recall). This is why an engine's AFR is controlled by the set-point on the map for a few minutes when it first starts.
My engine sounds exactly like an engine with a intake manifold leak when it's idling (rough idle). I have an AFR meter so I think I'll do a little trouble shooting before I take it to a shop. I may get myself out of this mess without spending much. I can set the AFR by installing resistors in the AFR leads to or from the ECU. I had to do this on a new Yamaha 2007 V-Star 1300 motorcycle that misfired when I bought it. I tried to return the MC to the dealer the day after I bought it but he would not accept it. Yamaha would not fix it. I had to fix the problem myself. A pol indicated that around 1/3 of the new V-Star 1300 misfired. After 6 months of tinkering with the MC I found that the O2 sensor was defective. It had it's good days and it's bad days. .
Oh well, I'll give it a go. Maybe someone can help me. I know a little about ECMs but not much.
I had a thought. I think I'll put the ECM in limp home mode by disconnecting the O2 sensor. Likely the AFR is normally controlled at around 14.7 to 1. In limp home I'm guessing the map is set at 14 to1 AFR. If the engine smooths out then the AFR must be the problem and not spark causing the misfire. I'm thinking that a spark problem would have cylinders that don't hit at all. Like I said before I can tell that I don't have a dead cylinder. The engine runs fine crusing down the HW. Rough idle is the only problem I'm aware of.
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This is a link to my forum. My handle was Dude. I was going to market my fuel management system but it was too much of a hassle and risk. I haven't bothered with this in 5 years and after a bad motorcycle wreck and a broke leg I gave up riding motorcycles. You may find this interesting if you like to play with your car and hot rod a bit. I designed in a power mode. It's explained on my forum.
BTW I discovered (off road) that my motorcycles MPG increased around 6 miles per gallon with a 14:1 AFR verses the factory setting of 14.7:1. One wouldn't think so but it's true. I don't know why.
http://forums.delphiforums.com/vstar...ages?msg=149.1
Last edited by DuWop; 06-10-2013 at 12:20 PM. Reason: additional information and link
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Good news. The panic attack is over!!! My Z3's engine is running normal again. Apparently after disconnecting the battery it requires quiet a bit of driving for the ECU to recover. My Jeep Grand Cherokee is like that also. I thought that might be the problem but I didn't expect it to take as long as it did. Now I can move on to changing the water pump, belts and hoses. I'm afraid to go out of town in the car until I do. 15 years is to long for the original hoses to be used.
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To the best of my knowledge this automatic transmission was used in all Z3s until 2001. All mine needed was the solenoids changed. The clutch plates showed very little wear with 125,000 miles on it.
http://etereman.com/blog/general-motors-automatic/common-problems-with-the-bmw-gm-4l30-e-transmission-and-how-to-fix-them/
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Just got my 99 M Coupe and am having the clunk as well as I mentioned in another thread...the question I haven't seen anyone ask here is; do I NEED to get this done ASAP? Replace the whole driveline? What are the consequences of not getting this done within the next 5-10K miles? I just bought it and am in the middle of an epic road trip trying to enjoy it and not worry about it!!
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If its just some ring and pinion lash, not whining, and the gear oil has no metal in it just run it like that. Look at post 41 again, if you have driveshaft problems it would be best to have it adressed. You really need to narrow down the problem a little more to determine whether its something to live with. Depending on where you are on the trip, someone will gladly recommend a shop to do a quick check, you mentioned you just bought it, is this a new noise or was it there when you picked it up.
Enjoy the trip..
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The miles and exposure to heat might also be a factor. My car is about 16 years old (built 10/96) but all its hoses and belts look and feel like new. It had 32,000 miles last fall when I bought it.
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I'm in the Carson City Reno area, but leaving for So Cal tomorrow...I think it's always made this sound, and it's not even very loud and only does it about half the time...I'll have to check the gear oil I guess. Thanks! having a blast up here!
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