Strong vibration on b18c between 2-3k rpm

KEVTI

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Joined
Oct 15, 2010
Messages
356
Good afternoon ladies and gents.

This is my first post for a little while as I am just getting my car back on the road. I have an ek4 with a b18c which I use for trackdays. The car has been off the road since my last trackday, but during that trackday I encountered a strong vibration from the engine between 2-3k rpm which appears to smooth out at higher revs. It happens randomly during the day with no apparent cause. Now I am a tech, so I have done the obviously checks, checked plugs,timing and compressions and there is no misfire. The car drives perfectly, just with a strong vibration. It feels to me about like when a duel mass flywheel goes. Now the engine is fitted with an exedy lightweight flywheel so I cannot understand what could go wrong with it. The engine mounts are new and are all fine with nothing fouling the chassis.

Has anyone had issues like this? And other ideas what could be the problem?

Thanks
 

b16 mini

Ek9 obsession
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1997 Ek9,1996 ek4 siR, 1972 b18c4 mini
How does your clutch feel?

What's your oil pressure like? Bad main bearings will give a vibration at that rpm
 

EK9 Matt

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May 24, 2015
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I've had this issue before and it was a knackered driveshaft, the harmonics would make the vibration go away at a certain speed but really bad at others.
 

b16 mini

Ek9 obsession
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1997 Ek9,1996 ek4 siR, 1972 b18c4 mini
I've had this issue before and it was a knackered driveshaft, the harmonics would make the vibration go away at a certain speed but really bad at others.
Wouldn't that be speed dependant rather than between a rpm range?
 

KEVTI

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Oct 15, 2010
Messages
356
Hi guys thanks for the reply so, oil pressure is normal and the engine sounds sweet. The clutch did start to slip at the end of the track day and the pedal is very high now but I'm not sure how that would cause a vibration dependant on engine speed? The vibration is permeant at those engine speeds and even when stationary so definitely not a drive shaft issue. The vibration is there even when the clutch is depressed too.

Thanks
 

jesse888

Ek9+Turbo+Nurburgring= Heaven
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The clutch mass will still be spinning with the engine as its bolted to the flywheel so i wouldnt rule the clutch out too quickly.
 

KEVTI

Member
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Oct 15, 2010
Messages
356
Ok, my plan of action is to remove the gearbox and inspect the clutch and f/w. The clutch was new before the trackday and was only just bed in!

Thanks
 
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