Morris Minor Owners Club

OK, the engine runs fine with its shiny new(ish) head, the new radiator is radiating like a radiant thing, and the fan belt has been adjusted to within an inch of its life.

But there is still a horrid screechy noise, and it's getting worse.

It only happens in gear when moving, and when either accelerating or decelerating; coasting in gear it isn't evident. It goes away when the clutch is fully depressed. It varies with speed, and has a v slow tempo at v low speed. It sounds really quite screechy.

Are any bells ringing here? -suggestions? (torching the Trav is Not An Option )

First thing I'd do is remove the fan belt and test run the car for a short period. If it still squeals, then it is conclusively NOT the dynamo/alternator, the water pump or the belt.

Then I'd check crankshaft end-float - just see if the crank pulley is moving at all when the clutch is operated in/out.

Next, I'd really be trying to ascertain where this noise is physically coming from - front of engine, back of engine, gearbox?

Could be clutch release bearing related?

Just some thoughts......

I thought there was a simple rule of thumb (I could be wrong though).

1) If the noise is still evident on depressing the clutch it's a wheel bearing.
2) If the noise disappears on depressing the clutch then it could be the clutch.

So on that synopsis it could be something to do with your clutch. Someone else may be able to drill down a bit further though. ;)

Maybe an inlet manifold/gasket air leak - or an exhaust leak ? Have we decided it's only there when the engine is running ? ie Coasting down a hill with engine off - no noise ? And - it's not there at all when idling ?

....been offline a bit.... Well, I tried removing the fan belt, and the noise is still there.

The noise is only there in gear. It disappears when the clutch is depressed.

There's now a fair bit of juddering too, and loss of power.

In neutral, the engine runs smoothly and responds smoothly to the throttle.

It's hard to try localising the noise, of course, as it's only there while the car is moving.

is there any oil in the gearbox??

there was when I checked last week, full up to the brim. I could always check again though...

Yup. Full up. Changed it not too long ago, and the oil that came out looked pretty clean too.

Oil in the diff?

Coasting down hill with engine switched off - any noise ?

not checked the diff recently, though oily last time I checked.

Noise disappears in neutral. Not tried coasting with engine off, but don't think it's transmission because of it only happening in gear, and the noise does seem to come from forward.

Noise disappears in neutral.

Your comment that the noise is not there when reving the engine and not present when in neutral suggest it is NOT on the engine or gearbox input side... However the comment that the noise dissapears when pressing the clutch indicates the opposite.
As the noise is road speed related it's likely to be the output side of gearbox or fuerther back in the drive train, however that can't be explained with the effect of pressing the clutch

So in brief, the symptoms conflict - meaning it's a bit wierd!

O god I hope not...

Major jobs on the roadside here aren't an option, so I've called someone who does garagey stuff. He's going to have a go at it in a fortnight's time. I'll post up the results when it's sorted...

The clutch release bearing does come to mind (as mentioned above), could be worth opening the inspection bung on the gearbox and giving the release bearing a squirt of WD40 and see if it quietens down, just be carefull not to get any on the clutch plate. It won't be a fix but might provide the solution.

It's not just the noise now, it's the vibration and loss of power. I'm pretty sure that there's something serious brewing down there, and I just don't have the time and facilities to do anything myself. Which is frustrating

We need more clues - is the oil pressure warning light coming on when it's idling (or at any other time) - is it overheating - is it burning oil - is there a cloud of blue smoke following on ?? When it's idling - if you take the oil filler cap off - is there a plume of smoke from the rocker cover ?
It could well be blown cylinder head gasket. In view of the past history - the vibration and loss of power certainly suggests so.
When the head was changed - was it re-tightened after the initial warm up ?

bmcecosse wrote:We need more clues - is the oil pressure warning light coming on when it's idling (or at any other time) - is it overheating - is it burning oil - is there a cloud of blue smoke following on ?? When it's idling - if you take the oil filler cap off - is there a plume of smoke from the rocker cover ?
It could well be blown cylinder head gasket. In view of the past history - the vibration and loss of power certainly suggests so.
When the head was changed - was it re-tightened after the initial warm up ?

Far be it from me to question and all that..... but he says it disappears when the clutch is depressed, and it only does it when pulling in gear?

Sounds like major gearbox trouble to me - possibly layshaft gone to lunch? (I'd especially suspect this if it did it in all gears except top gear)

So difficult to diagnose a noise over the internet though, isn't it?

Well - i'm thinking the 'loss of power' and 'vibration' which to me are engine/head gasket problems. No mention of gear changing problems or jumping out of gear. I just think when it's idling it's managing to get by - but when asked to do some work - the gaskeis blown between two cylinders and so it's only running on the other two.

Yep - I know where you're coming from, but it doesn't cover the squealing/disappearing with clutch in?

A stuffed layshaft (on its own) won't make it jump out of gear or have any gear selection problems, but will squeal like hell under load - and if it's gone badly enough (and indeed this fault seems to be getting worse) it could be jamming enough to give power loss, vibration etc.

What it would do though is creat a fair bit of swarf in the gearbox - I think I'd be draining the gearbox oil through a filter to see what sort of solids come out. You always get a little "iron filings" type swarf with these, but anything more than "metal dust" size, and there's something nasty going on IMHO.

Mind you, I'm guessing here too!

Looking forward to knowing the real outcome of this - so sorry for Dru, as either way it sounds a bit on the serious side.

Cheers!

Well - in top gear the laygear does nothing - but it could be ! My money is on head gasket - again.