Misfire = Vibrations?, but no codes?
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Misfire = Vibrations?, but no codes? As some of you know, i have been chasing vibrations in my 2000 M6 WS6 (45000 miles) for about a year or more now. 
The are everywhere in the RPM range, but more so, or more pronounced in the 1800 to 2500 range. Any gear, even netrual (just revving it up to the problem range, will bounce my steering wheel) Car sounds like it has a slight miss at idle, not sure though.
Im going to pull the NGK T55's i believe i gapped to .50,,, i put in either last year or the year before and the new MSD wires to see if i see anything funky,, but
1. what am i looking for on the plugs,, should they all look about the same if they are not the culprit?
B. Can a misfire due to a plug problem cause these vibrations?
3. - not sure if i have a wire touching a header, but can that really cause a misfire that would result in vibrations this bad?
-My clutch is working fine (Spec 3)
-The M12 i installed last year has been triple checked, no signs of problems there, posi rebuilt due to grinding noises when i turned, those issues are gone
- Car does it in neutral, so it cant be the DS, rear, tires or wheels
- Engine movement isnt crazy, but there is some,, so im 89% sure its not the stock motor mounts,, when i hold the TB blade open the engine does shake some, but nothing that looks like its jumping out of the engine bay...
- I am wearing the stock trans mount,, i do have one stripped bolt hole for the tranny crossmember,, i can tighten the bolt, but not to torque specs.
I am not running any misfire codes (i always have a P0480, but my fans run fine)
Just trying to get some clues on whats going on..
Thanx
Wayne
The are everywhere in the RPM range, but more so, or more pronounced in the 1800 to 2500 range. Any gear, even netrual (just revving it up to the problem range, will bounce my steering wheel) Car sounds like it has a slight miss at idle, not sure though. Im going to pull the NGK T55's i believe i gapped to .50,,, i put in either last year or the year before and the new MSD wires to see if i see anything funky,, but
1. what am i looking for on the plugs,, should they all look about the same if they are not the culprit?
B. Can a misfire due to a plug problem cause these vibrations?
3. - not sure if i have a wire touching a header, but can that really cause a misfire that would result in vibrations this bad?
-My clutch is working fine (Spec 3)
-The M12 i installed last year has been triple checked, no signs of problems there, posi rebuilt due to grinding noises when i turned, those issues are gone
- Car does it in neutral, so it cant be the DS, rear, tires or wheels
- Engine movement isnt crazy, but there is some,, so im 89% sure its not the stock motor mounts,, when i hold the TB blade open the engine does shake some, but nothing that looks like its jumping out of the engine bay...
- I am wearing the stock trans mount,, i do have one stripped bolt hole for the tranny crossmember,, i can tighten the bolt, but not to torque specs.
I am not running any misfire codes (i always have a P0480, but my fans run fine)
Just trying to get some clues on whats going on..
Thanx
Wayne
pull the plugs n wires and see what they look like, i would go ahead and replace them... all of those questions above would cause a misfire! pretty much any vibration would cause a vibration but to what extent im not sure... i would start with that and see how that goes... does your service engine light come on when you start your car? to make sure the bulb is not out?
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only hand washed, but that was last done b4 the 2007 TA Nats,,, and really only wiped off, no water thrown directly on the motor.
The SES light is always on due to the p0480 code, but i keep a lil code reader in the car and check it allllll the time,, its always the p0480 (Fan Relay Cir 1)
The SES light is always on due to the p0480 code, but i keep a lil code reader in the car and check it allllll the time,, its always the p0480 (Fan Relay Cir 1)
Last edited by Bad Blue WS6; Nov 11, 2009 at 01:09 PM. Reason: i cant spell the word "the"
Thread Starter
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passenger side front 3 are out, they also look good, regapped to .060 from teh .045 i had them set at,,, so unless number 8 shows me something,,, im still at square 1,, i will get that finished up tomorrow.
If you have any ideas on my vibs, feel free to to share.
If you have any ideas on my vibs, feel free to to share.
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When I wired in a window switch for nitrous I did it wrong and my car idled like it had a damn trex cam in it cause of a misfire. If it idles as bad as you make it sound you should be able to tell when driving if its really a misfire.
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From: NW Florida
Determine you definately do not have an engine misfire first ( an infrared thermomer aimed at each individual exhaust manifold runner at idle will indicate a lazy cylinder )
If all is OK there I would check your pressure plate for the vibration source, it's possible for the ring to be forced slightly off center by severe use and this will cause an out of balance vibration all through the RPM range. This has happened to me one time , and your symptoms sound farmiliar......Good luck!
If all is OK there I would check your pressure plate for the vibration source, it's possible for the ring to be forced slightly off center by severe use and this will cause an out of balance vibration all through the RPM range. This has happened to me one time , and your symptoms sound farmiliar......Good luck!
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Glad to see this thread with new ideas over the last couple days,, how you all got signed in on here is beyond me (i was out of commision on my systems)
Anywho,, got number 8 done and also regapped, so all are now at .060,, this seemed to smooth my idle out a bit, but the awful vibs are still there,, so i moved on to the pushrod rod thing,,, bingo. The farthest one back on the drivers side was bent when i rolled it on a mirror,, not like a question mark, or an "S" as some folks describe on here,, but it had a wobble, and you could see the end rolling in a messed up sorta way, egg shaped or whatever when it rolled. The others looked ok (There were Comp PR's in there from the previous owner, so thats what im replacing them with) Upon first taking the car out, it does feel much better than it did in the 1800 - 2500 RPM range,,, i didint get on it or anything,, the vibs are most noticable when you're just "crusin" anyways... letting them cool down now before i take it out again. My car has vibs anyways, so im going to drive it around some more today to get myself to 100% sure that they were the cause, but it is looking like a bent PR was the cause. Thanx to everyone on here that has taken the time to help a comlplete stranger,, could'nt have done it without you all!
I will update the thread in a couple of days to report that i finally believe its over,,
(((I also noticed my springs have a green stripe on them,,,, (they also looked good) are those stock?)))
Thanx again
Wayne
Anywho,, got number 8 done and also regapped, so all are now at .060,, this seemed to smooth my idle out a bit, but the awful vibs are still there,, so i moved on to the pushrod rod thing,,, bingo. The farthest one back on the drivers side was bent when i rolled it on a mirror,, not like a question mark, or an "S" as some folks describe on here,, but it had a wobble, and you could see the end rolling in a messed up sorta way, egg shaped or whatever when it rolled. The others looked ok (There were Comp PR's in there from the previous owner, so thats what im replacing them with) Upon first taking the car out, it does feel much better than it did in the 1800 - 2500 RPM range,,, i didint get on it or anything,, the vibs are most noticable when you're just "crusin" anyways... letting them cool down now before i take it out again. My car has vibs anyways, so im going to drive it around some more today to get myself to 100% sure that they were the cause, but it is looking like a bent PR was the cause. Thanx to everyone on here that has taken the time to help a comlplete stranger,, could'nt have done it without you all!
I will update the thread in a couple of days to report that i finally believe its over,,
(((I also noticed my springs have a green stripe on them,,,, (they also looked good) are those stock?)))
Thanx again
Wayne
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while i dont think the 1800 to 2500 vibration is gone, the car is running and idleing much, much smoother. I still get some resonance at the 1800 to 2500 RPM range, so it is still there, but seems "not as violent" when shaking my butt around in the seat.
I have to save up some more coin (hopfully i win the 50/50 drawing my work is having today raising money for United Way,,, its over 700 bux right now, so the winner will take 350.00),, im going to try replacing the crank pulley next to see if that does anything.
Can anyone tell me about the green stripe on my valve springs,, is that a stock spring?
I have to save up some more coin (hopfully i win the 50/50 drawing my work is having today raising money for United Way,,, its over 700 bux right now, so the winner will take 350.00),, im going to try replacing the crank pulley next to see if that does anything.
Can anyone tell me about the green stripe on my valve springs,, is that a stock spring?