BMW M5 Forum and M6 Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
374 Posts
Discussion Starter #1
Hi Guys,
I've tried searching this issue but haven't really found anything too concrete... I seem to have an engine vibration that kicks in at a few different points along the RPM range, first at around 1,500 RPM and then comes and goes at various points up the rev scale..

For quite some time I thought I had a wheel balance or tailshaft vibration or something, because when I drive I can feel a slight shake at certain speeds. After having wheel aligments and new diff bushes etc, I finally sat in the car stationary and slowly brought the revs up and discovered a noticeable engine vibration, which I now realise is the cause of the phantom shake while driving! :dunno:

Any ideas what this could be? This has been present since I bought the car which drives and sounds fine other than that, and occurs irrespective of clutch position (I've never had the clutch off it). It's not a misfire and I have no relevant codes (only the dreaded thermostat!). It feels like some sort of balance issue. I'm hoping this is nothing internal! Any help would be greatly appreciated.
 

·
Registered
2002 BMW M5
Joined
·
1,368 Posts
Check the driveshaft flex joint for any cracks.
 

·
Registered
Joined
·
3,533 Posts
rated m did you read his post fully? any how m5 sydney i have the same issue with mine im going to be checking that my throttle bodies are in synk first then move on to see if my flywheel needs to be rebalenced
 
  • Like
Reactions: M5 Sydney

·
Registered
2002 BMW M5
Joined
·
1,368 Posts
rated m did you read his post fully? any how m5 sydney i have the same issue with mine im going to be checking that my throttle bodies are in synk first then move on to see if my flywheel needs to be rebalenced
Oh your correct I read it too fast, I have the same problem on mine, could very well be the flywheel but it doesn't bother me enough to take the tranny off again.
 

·
Registered
Joined
·
374 Posts
Discussion Starter #5
i have the same issue with mine im going to be checking that my throttle bodies are in synk first then move on to see if my flywheel needs to be rebalenced
Thanks guys, I've been doing some further research today and I'll take your advice plus check engine/gearbox/exhaust mounts, harmonic balancer, clutch fan/water pump. Fingers crossed!
 

·
Registered
Joined
·
5,532 Posts
Don't forget the oil filter housing mounts and oil pipes going to and from it....outside chance !
 
  • Like
Reactions: M5 Sydney

·
Registered
Joined
·
3,968 Posts
make sure the exhaust mounts tword the rear aren't collapsed allowing the exhaust to touch the crossmember. search for posts by me and the word "vibration". don't go down the same road i did, on my last m5 i replaced everything chasing these vibrations, motor mounts, tranny mounts, vibration damper etc. unfortunately some m5's have more vibration problems than others, especially the early production cars. if you feel the vibrations in the 1500 and 3000rpm range you might as well just stop now cause theres no way to "fix" it.
 

·
Registered
Joined
·
374 Posts
Discussion Starter #8
Don't forget the oil filter housing mounts and oil pipes going to and from it....outside chance !
Housing mounts I've changed. Oil pipes I wouldn't have even thought of! I'll watch them while I raise the revs and make sure they're not shaking about...
 

·
Registered
Joined
·
374 Posts
Discussion Starter #9
make sure the exhaust mounts tword the rear aren't collapsed allowing the exhaust to touch the crossmember. search for posts by me and the word "vibration". don't go down the same road i did, on my last m5 i replaced everything chasing these vibrations, motor mounts, tranny mounts, vibration damper etc. unfortunately some m5's have more vibration problems than others, especially the early production cars. if you feel the vibrations in the 1500 and 3000rpm range you might as well just stop now cause theres no way to "fix" it.
Thanks - that's interesting. Do you think they were something that was there from new? Fairly surprising for BMW... I think mine continue past 3000rpm, I'll check and report back. They certainly detract from the driving experience at around 80 kph...
 

·
Registered
Joined
·
450 Posts
Check motor & tranny mounts

While replacing a PS hose that was leaking I noticed the pass side motor mount has some oil (or some type of fluid) leaking and the driver's side was basically soaked w/ PS fluid (actually ATF fluid), which probably isn't good for it. No major shaking so far, but I'm going to swap them out anyway to be safe.
 

·
Registered
Joined
·
3,968 Posts
all these engines have at least some vibration. just about every s62 i've seen has a vibration revving in neutral around 2800-3000rpms. v8's simply cannot be balanced perfectly. as i said, i chased this vibration on my old 00' m5 to no avail. certain engines have inherent vibration problems, 4cyls are the worst. hence why many 4cyl engines incorporate balance shafts etc. a v8 is basically two 4cyls slammed together. its the way the engine fires and the speed of the pistons etc which cause the vibrations. now maybe you do have a different problem so i dont want to discourage you right off the start but if you replace a bunch of parts and still have the issue then you're probably in the same boat i was.
 

·
Registered
Joined
·
374 Posts
Discussion Starter #12
While replacing a PS hose that was leaking I noticed the pass side motor mount has some oil (or some type of fluid) leaking and the driver's side was basically soaked w/ PS fluid (actually ATF fluid), which probably isn't good for it. No major shaking so far, but I'm going to swap them out anyway to be safe.
I've got the exact same problem. One engine mount is wet from power steering fluid on the right I think. I'm going to change my power steering hoses and wash it all down and re-evaluate. Slipping the clutch in 1st and reverse with the brakes on didn't seem to show undue engine twist, but I may change the mount/s to eliminate the suspicion.
 

·
Registered
Joined
·
81 Posts
It's sad to know that such a perfect (Almost) engine is suffering from something like this. I have a '99 M5 and got the same issue with the same RPM gaps. What I was scared was that I had some compression issues or a valve problem. But after checking the compression 6 times and each cylinder had equal rate and it wasn't low at all, I almost gave up until I saw this threat. It cost me a little fortune to make all the diagnostics and replacing the spark plugs, motor & tranny mouths, gearbox(itself), all the engine harness & piping, etc. (something about 9000$+). I could get a stage 4 clutch and a new lightweight flywheel for that, but i was more concerned about the vibration that I had. Thank you for posting this issue here, so maybe other will be less sad than me((( But if some one ever solve this issue, pls let me know about it.
 

·
Registered
Joined
·
374 Posts
Discussion Starter #14
Engine vibration fixed for $25!!!

I thought I should revive this old thread as I've just had success in fixing this, and now have a practically vibration free S62 right across the rev range!

Related engine maintenance that I can recall over the last 40,000 kms has included everything from:
- new MAFS
- new oil filter mounts
- new exhaust mounts
- new clutch fan
- 4 x CPS and vanos o-rings and board re-solder
- spark plugs
- fuel pump & filter
- valve cover gaskets
- new oil seperators including all connected crankcase ventilation hoses
- new thermostat
- all under plenum vacuum hoses and recommended part replacements such as non return valve, electr. valve and fuel tank breather valve.

While the car has been running well, I've still had niggling doubts about whether it has been running perfectly, and the vibration always remained. It also had a slightly "pulsy" exhaust note and didn't run particularly well in hot weather (making me think I desperately needed to relocate the intake air temp sender).

However after all my maintenance I run code free according to the peak.

However... I've also always had some cold start issues that have recently gotten worse. These would be briefly eliminated each time I changed spark plugs, but quickly returned. The beast always used to only start from cold on the second attempt, but this recently became the third, fourth or even fifth attempt. To fix this, a few days ago I tried replacing the temperature sender unit located on the thermostat housing. Only $25 from my local dealer and 2 minutes to change out. Unbelievable.....! :applause:

She is now running like a whole new car! Absolutely silky smooth tractable engine, much improved exhaust note (she now sounds like a happy, relaxed V8), faster, and incredibly, no real engine vibration when I slowly increase the revs across the range while at standstill! :1:

I assume it's been running rich all this time, so I will change the spark plugs as I think they could be somewhat fouled and she still doesn't always start first time from cold (but always strongly from second time now).

But I can't overstate the improvement in running and how much of a nicer car it is now.

Not sure what the lesson is here, perhaps the peake isn't enough to keep an eye on general engine health, and we should be looking more regularly at fuel trims etc? But for now, anyone with similar symptoms to me could consider changing out the temp sender part 3621703993.

Nick
 
1 - 15 of 15 Posts
Top