guibo

 

the problem was more noticeable "revving in neutral".
CPS may be an issue here.
Any codes (if you have a code reader)?

 

Not a lot to go on nightkrawler...

 

i knwo what you are talking about and i also had this, it kindof went away after new cps but i can sometimes still feel it.

 

guibo?

 

Spark plug ??

 

...many times this is related to the clutch/flywheel / / no worries

 

I have vibrations in a number of different "zones" in the rev range. The main zones are around 1250rpm and 2750rpm, don't remember exactly. The vibrations seem to be magnified by the exhaust, but I don't know what the root cause is. A bad CPS could probably cause something like this.

I've also suspected the flywheel but that would perhaps manifest slightly differently. For me, the amount of vibration will change somewhat depending on the temperature of the engine. If the root cause was the flywheel then I don't think this would be the case. Also, clutch in/out doesn't really seem to make much of a difference to the vibrations. If it was the flywheel then I think one would somehow feel the difference when engaging the clutch.

 

i knew everyone was going to shout guibo, its not the guibo. maybe i should have been a bit more specific. when i say reving in neutral, i mean parked. cant be the guibo as when the car is not moving the guibo is not turning. i had a vibration like this on my 540 except at 1200rpm. i changed every possible culprit, only thing that was left was the flywheel. this feels very much the same just at a different rpm.

i do have another bad exhaust cps that just started turning the cel on a few days ago. when it acts up i notice a slight power loss and the rumble/blatty exhaust tone. i guess anything is possible but this really feels more like something out of balance. i should have the new cps today so we'll see if that fixes it but i doubt it.

i've checked the whole exhaust system and i dont see any bad mounts but i did notice that the exhaust bolts to the tranny via a bracket. i suppose it is possible that it is a resonance from the exhaust being transmitted through the bracket. i may disconnect it this weekend and see if it makes any difference.

 

How are your engine mounts looking?

 

I have the same thing around 2700. I think it is related to the exhaust. I have played around with it moving, not moving, warm, cold, and it does fluculate moderately. It also does it when I back off the accelerator and coast down through 2700 rpm. I thought it was tied to the tubi. Wish I could help you, but you are not alone.

 

NVH

Mine did not change after 1 cps change. However, it was much improved after pre and post sensor changes with new MAF's.

good luck,

ssomed

 

im thinking it is either related to the exhaust or the dual mass flywheel.

 

sounds like you need to just throw it in the trash and get a new car ill stop by with my dump truck...mmmmmm

 

Have you checked to see if the harmonic balancer has shifted. I have replaced these in the past to correct for engine vibrations (drone) at specific RPM.

Andy

 

Have you checked to see if the harmonic balancer has shifted. I have replaced these in the past to correct for engine vibrations (drone) at specific RPM.

Andy

Andy,

What was the mileage and rpm vibration when you had this replaced ?




Regardz,

J Irwan

 

what do you mean by shifted? the crank pulley on these can only go on one way.

 

First timer here on the forum. Anyway, I also suffer from the annoying vibration, most significant around 2k and 3k rpm. I haven't got any codes related to misfires or anything else and my friends seems to ask is this running on all cylinders while reving the engine standing still. I've already done something to find the culprit.

I've replaced my flywheel and clutch assembly, had my exhaust system disconnected from the chassis during engine running (except from the manifolds) and the fan (viscous coupling) disconnected. It feels like something is out of balance. No popping from the exhaust, so I trust no misfires either.

I know my viscous coupling bearing has play, the water pump axle has play and one of my belt pulleys creates a noise at cold ambient temperatures. No other problems whatsoever. Vanos solenoids are replaced about a year ago along with the MAFs.

I'm thinking next about checking the harmonic damper, maybe running my engine shortly without the belt also. I really can't find any other reason for the vibration, since my flywheel (one of the heaviest parts) is replaced. Also no codes. Play in connecting rod bearings seems a bit far fetched, since so many other suffer from the same symptoms.

But before that, a full body paint job has to be completed

 

First timer here on the forum. Anyway, I also suffer from the annoying vibration, most significant around 2k and 3k rpm. I haven't got any codes related to misfires or anything else and my friends seems to ask is this running on all cylinders while reving the engine standing still. I've already done something to find the culprit.

I've replaced my flywheel and clutch assembly, had my exhaust system disconnected from the chassis during engine running (except from the manifolds) and the fan (viscous coupling) disconnected. It feels like something is out of balance. No popping from the exhaust, so I trust no misfires either.

I know my viscous coupling bearing has play, the water pump axle has play and one of my belt pulleys creates a noise at cold ambient temperatures. No other problems whatsoever. Vanos solenoids are replaced about a year ago along with the MAFs.

I'm thinking next about checking the harmonic damper, maybe running my engine shortly without the belt also. I really can't find any other reason for the vibration, since my flywheel (one of the heaviest parts) is replaced. Also no codes. Play in connecting rod bearings seems a bit far fetched, since so many other suffer from the same symptoms.

But before that, a full body paint job has to be completed

this is both good news and bad. good cause i was thinking the flywheel could be the culprit. bad cause you changed all these parts and still have the issue.

andy, what part are you referring to? here is the diagram, RealOEM.COM   BMW E39 M5 BELT DRIVE-VIBRATION DAMPER

 

Knightkrawler. The outer ring of the damper is isolated from the inner by a rubber liner. If the outer ring shifts this will throw the ballance of the crankshaft out. Symptoms are very similar to the above complaints.

Andy

 

I am dealing with the same issue. Vibrations/pulsations that are felt mainly through the shifter but can be felt under pedal area as well. Most noticeable (vibration/resonating sound) around 2K rpms. I thought is was related to the exhaust as it feels like pulsating resonance being transmitted to the tranny, but can't find anything obvious. Another ways to describe it is like having an exhaust leak which I do have at the ss x pipe connection at the cats. I will probably get the x pipe welded in and see if that changes anything, but I'm not very hopeful.

 

I had a leak as well and welded it

 

From the drawing I would say it is item #1 the vibration damper.

Andy

 

I was just discussing the vibration issue between 2K and 4K rpms on my thread today. Does your SES light come on at some point? When I first start driving it feels OK, it all starts when the rpm's drop below 2k or I'm idling at a light. I've changed all sensors in the MAPS, CPS's, crank, O2 sensors etc on the car and I still continue to get the vibration and a weak feeling engine. I also have the Tubi (and Supersprint racing cats). My fault codes read cataylitic efficiency (something) bank 1 and 2. I don't have an answer, just lots of questions.

 

no, no check engine light. this isnt a misfire etc problem.

andy-you had this issue on an m5 or some other car? i actually checked the pulley and i dont see it wobbeling etc when the engine is running.

 

Nightkrawler, good thing I'm responsible just for the flywheel change that I did myself and with a new flywheel costing 30% of a new one

The thing that made me think the flywheel was shot, came from the assumption that while reving the engine with a "snap" (blip the throttle) you could hear a metallic sound like something was hitting its limit. Flywheel was the first thing on my mind of course. But the vibration damper could make a similar noise. I've seen vibration dampers that make a horrible noise (in a five cylinder diesel engine for example) and the generator, two pulleys, water pump, power steering pump and the vacuum pump was replaced before they took the vibration damper out and with a long heavy screwdriver tried to spin it while attached to a vise. Only then I could see it move (obviously took a great deal of effort). It just wasn't attached in the outer edge. And no visual evidence of the vibration damper being shot before that.

 

so what are you saying, your crank pulley(damper) was shot? i though you said you still have the vibration? did you put in a new flywheel or used, stock dual mass or after market?

 

Yes I do have vibrations. I was just telling an example of a damper case, where it was impossible to make any assumptions before the damper itself was on the table.

The flywheel was new as told earlier, stock dual mass. The old and new one felt similar and I suspect a worn/bad flywheel would indicate other symptoms also.

I'll be checking the damper later on.. still have the paint job undone. After that, might be taking the vanos apart myself and sending them to be fixed to the Dr. himself :biggrinbounce:

 

im thinking now the culprit is the exhaust. today i replaced the two old red rubber style hangers with the new style black ones. immediately i noticed the vibration was much reduced. the original ones were definitely almost shot. i then disconnected the bracket that bolts to the back of the tranny. took her for a spin and the vibration was reduced. i ended up bolting it back up after i replaced the 4 rubber mounts on it. it has to be a resonance in the exhaust that is transmitting through the body.

 

well... im stumped. last night i was messing around with the car and it seems the vibration was back full force. it seems that some days it's not very noticeable and some days it's worse. temperature seems to play a part here. last night it was bitter cold, and it was definitely worse than usual. this has me leaning tword some type of mount, rubber/fluid filled mount. prehaps engine or tranny.

 

Any latest update ?
Any resolution to this ?



Regardz,

J Irwan

 

no, havent made any progress. idk if it is in the engine, exhaust, or flywheel/clutch. what parts of the clutch are actually spinning when the engine is being rev'd in neutral?