30 replies to this topic

[tino]

Hi All,
 
Hopefully you can either put my mind at rest or point me in the right direction. My mini has a slight whirring noise at idle, that will quieten if the clutch is depressed (but not go away) and also isn't audible if the rev's increase.

 

I have uploaded a video to my website, which hopefully you can access.
 
https://tinoest.co.uk/img/IMG_8086.mov

 

https://tinoest.co.uk/img/IMG_8131.mov

I thought it might be the idler gear bearing, but it's more prominent on the water pump side than the clutch.

 

Is this just a standard normal sound? I can't hear it whilst in gear and over the normal engine and road noise, but that's not to say it's not there.

 

Thanks for any advice.

[nicklouse]

Disconnect the fan belt and see if the noise goes.

 

sounds very fan like to me.

[tino]

Disconnect the fan belt and see if the noise goes.

sounds very fan like to me.

Sorry should have said I disconnected the belt and the noise remained. So not alternator or water pump related.

[cal844]

Thrust bearing or crankshaft related

[Stevie W]

Possibly idler gear or drop gear noise? This usually goes away or reduces with the clutch disengaged

 

Cheers, Steve.

[tino]

Thanks is the drop gears on the water pump side?

I don’t think it’s thrust bearing as it would be noisier when the clutch was depressed I believe?

Sounds like it’s an engine out job either way, so will have to acquire an engine hoist.

[Stevie W]

Drop gears are on the other end of the engine from the water pump, behind the clutch housing.

Normally the idler gear which is between the primary gear on the crankshaft and the gearbox input (1st motion shaft) can rattle or make a whirring noise if one of the bearings is worn or the idler gear end float is to large.

 

The bushes on the primary gear can also wear, which can generate a similar noise.

 

Dipping the clutch stops the 3 gears rotating which in turn makes the noise stop.

 

Cheers, Steve.

Edited by Stevie W, 01 May 2024 - 08:05 PM.

[tino]

Weird it sounds louder on the other side to all those.

Thanks for confirming it’s not just a normal noise.

I’ll look to take the engine out and investigate which one is causing it as I assume ignoring it is a bad idea!

[Spider]

Check the Crank End Float. With the engine off, if you lever the crank back carefully at the pulley end then have someone depress the clutch look to see (or if you can measure) the crank coming back.

[tino]

Check the Crank End Float. With the engine off, if you lever the crank back carefully at the pulley end then have someone depress the clutch look to see (or if you can measure) the crank coming back.

Just to make sure I’m understanding you mean with the engine still in the car?

Do I need to remove the fan belt? Or have I misunderstood you completely.

I assume it’s the crankshaft end float play in the Haynes manual I’m measuring?

[Spider]

 

Check the Crank End Float. With the engine off, if you lever the crank back carefully at the pulley end then have someone depress the clutch look to see (or if you can measure) the crank coming back.

Just to make sure I’m understanding you mean with the engine still in the car?

Do I need to remove the fan belt? Or have I misunderstood you completely.

I assume it’s the crankshaft end float play in the Haynes manual I’m measuring?

 

 

Yes, you can check this with the engine in the car and you can leave the fan belt on. You can usually get a lever in between the engine mount bracket and the centre bolt here (that's the best point to press against).

I'm not sure what the Haynes manual says here, it probably showed a block up side down and measuring the end float on the thrust washers with feeler gauges. It's the same measurement, but doing it a different way.

[tino]

 

 

Check the Crank End Float. With the engine off, if you lever the crank back carefully at the pulley end then have someone depress the clutch look to see (or if you can measure) the crank coming back.

Just to make sure I’m understanding you mean with the engine still in the car?

Do I need to remove the fan belt? Or have I misunderstood you completely.

I assume it’s the crankshaft end float play in the Haynes manual I’m measuring?

Yes, you can check this with the engine in the car and you can leave the fan belt on. You can usually get a lever in between the engine mount bracket and the centre bolt here (that's the best point to press against).

I'm not sure what the Haynes manual says here, it probably showed a block up side down and measuring the end float on the thrust washers with feeler gauges. It's the same measurement, but doing it a different way.

I’ve tried this and I can’t measure or see any movement. Either I’m being too timid pushing against the bolt or it’s too minute to measure.

The clutch side had a lot of dirt between the bolt and the clutch casing, which I’ve cleaned up as I tried to measure it from that side also.

Edited by tino, 01 May 2024 - 02:42 PM.

[Ethel]

The clutch side also has the clutch 

 

The point being you can't see the crank endfloat there. Spider's suggestion was to push the crank (fan belt) pulley against the engine, then see how much the clutch pushes it back out. You're right it shouldn't be much, but you should be able to feel it if you can get somebody to press the pedal while you have a finger bridging the pulley & timing cover. Better still if you can find somewhere to insert some feeler blades, or lay your hands on a dial gauge. 

[tino]

The clutch side also has the clutch

The point being you can't see the crank endfloat there. Spider's suggestion was to push the crank (fan belt) pulley against the engine, then see how much the clutch pushes it back out. You're right it shouldn't be much, but you should be able to feel it if you can get somebody to press the pedal while you have a finger bridging the pulley & timing cover. Better still if you can find somewhere to insert some feeler blades, or lay your hands on a dial gauge.

I managed to put a feeler gauge between the timing marks and pulley. It’s 0.025 thou after pressing the clutch and 0.022 thou after I’ve pushed it back towards the block.

Edited by tino, 01 May 2024 - 06:31 PM.

[Spider]

 

The clutch side also has the clutch

The point being you can't see the crank endfloat there. Spider's suggestion was to push the crank (fan belt) pulley against the engine, then see how much the clutch pushes it back out. You're right it shouldn't be much, but you should be able to feel it if you can get somebody to press the pedal while you have a finger bridging the pulley & timing cover. Better still if you can find somewhere to insert some feeler blades, or lay your hands on a dial gauge.

I managed to put a feeler gauge between the timing marks and pulley. It’s 0.025 thou after pressing the clutch and 0.022 thou after I’ve pushed it back towards the block.

 

 

As Ethal has said, that sounds good to me !


Listening to your video, it has an 'Alternator' sound about it to me but you say that you've tried it with the fan belt removed, so that eliminated the alternator and water pump. With the crank end float appearing to be good, and given all else in your descriptions, I think it's the drop gears.