rattly tappy noise - fixed
Turbo Mini Forums

When I start the mini it runs perfectly, however once it warms up in neutral at idle a sort of rattling tapping noise begins to emit at idle, it is worse at 1000rpm and either goes awayt or is drowned out by the fan, weber etc at 1500 rpm.

If I push the clutch in it goes away, so that seems to rule out bearings and the oil pressure rockets up when I start it. I though ititially it was a problem with the clutch but now due to removing the flywheel cover and inspecting it it seems to be something else.

Before I drop the oil and pull the transfer casing off to see if the drop gears have shat themselves does anyone else have any other thoughts. the idler has about 8 thou clearence iirc, so I don't think its that rattling about.

I have a video of the noise too. I appreciate without hearing the noise in person its difficult to diagnose.

one video at idle, the other one is at 1500.

http://s168.photobucket.com/albums/u196/mi...¤t=MOV00087.flv

http://s168.photobucket.com/albums/u196/mi...¤t=MOV00085.flv

Edited by minimole23 on 15th Apr, 2009.

bearing shagged on the idler?

Do you have SC drop gears?

If so its probably fine

Could be just the release bearing?

Thats what i'm afraid of, though can't see how I could have trashed it in 800 miles.

Edited by minimole23 on 12th Apr, 2009.

Is the noise definatly coming from the clutch side. Could be the timing chain. If its clucth side then it could be the primary gear thrust washer or c washer. Other than that mate I don't know?

drop gears on idle sound terminal especially when the oils warm and thin if they are SC drops.

with the clutch cover off this sounds worse than it is.
when you push the clutch in the noise goes away, by doing that you disengage the drop gears from drive, so if theres a problem ? it will lie with the drop gears, but it sounds terminal to me.
i just noticed you stated that they are helicals not SC

i know your exhaust is blowing also please fix that. its a combination diffrent noises which make the engine seem terminal ........... anyway if you feel like pulling the drop gears out to inspect, i would go for the SC timkin type idler drop gear set up.

Edited by BENROSS on 12th Apr, 2009.

Release bearing?

I'll pull the transfer casing tomorrow and let you know, bloody thing!

Benross, you have very well tuned ears, I need to fit a clamp to the back box.

It could just be a bit of chatter from the drops.

Sometimes, the wrong mixture or timing can make it hunt around at idle causing the idler gear to rattle between the thrusts.

Before you pull it to bits, just adjust the settings at idle. The noise might just disappear.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

This sounds like drop gear rattle, Let me guess heavy cam, if your using a 286 then at idle Hot this noise is very common,

I'm using a 285 scatter cam, I will type out my findings in a sec.

Unfortunately Paul s you are a little too late! I have just pulled it to bits and the drops are fine. I needed to pull it to bits anyway to replace the primary gear oil seal but never mind.

does 12 thou sound excessive for the primary gear endfloat?

iirc correcty this should be no more than 6 thou?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Bloody hell, 30 odd quid for a small circle of metal. Well the primary gear is now back to 4 thou which is good, just need to deal with the primary gear oil seal and bolt everything back together.

i find that with hot cams (Helical) primary gears just keep losening up due to the c clip assy wearing.

Get a heavy duty oil seal from hythe-performance they are brilliant.