knocking noise

[zacseaman]

Since 2 days ago I have been having a problem with a knocking noise. It happens when I pull away in first, and the noise is coming from the engine bay. The noise is exactly the noise if you accelerate in a gear to high, but it happnes pulling away in first now. Any Ideas?
Many thanks in advance

[dalebrignall]

do you get the noise if you go into 2nd gear and accellerate as well could be end shells need replacing is the oil pressure light out .

[mogbob]

A single clonk might be a fractured engine steady bar ?
Bob

[simmitc]

Does it continue under load in other gears? If yes, could be the head gasket. If it's only when first pulling off, check all engine mounts and towers, not just the steady bar (also gearbox mounts). If it is not in time with the engine, then it could also be a loose damper or some other suspension component. Does the noise occur when you rev the engine in neutral?

[zacseaman]

It happens when I pull off and sometimes in traffic when rolling, so pulling in second gear but would probably be more appropriate in first but obviously can't get in first as I'm rolling. I have checked all engine mounts and steady bar its all OK.. Really have no idea

[MarkyB]

The noise is exactly the noise if you accelerate in a gear too high

If it's a kind of rattle I'd suggest it's pinking, try retarding the timing a bit.

[bmcecosse]

" obviously can't get in first as I'm rolling " Ehh? Why ever not??? Sounds like exhaust rattling against the body - and yes - possibly caused by broken steady bar location.....

[zacseaman]

You have to be stopped to get it in first no? If I try to put it in first when moving it just crunches as there is no syncro on first gear? I will have a look at the exhaust tomorrow it would make sense as I guess it is at the same revs where it happens pulling away and occasionally in second, resonance would cause the vibration at a guess thanks

[bmcecosse]

Double de clutch into first gear - simples !

[MarkyB]

Crash boxes aren't that common any more Roy.

[bmcecosse]

Very common with A series engines..... No need for any 'crashing' !!!

[brucek]

OK - hands up who doesn't know how to double de-clutch???

My guess is it's not a skill that's taught anymore so some won't have been aware that you had to do it at one stage cos there was no synchromesh anywhere!! Btw I'm a child of the mid 60's and I was taught by my grandad, dad AND driving instructor so I've no excuses!!

If enough want to know how to do it, we'll ask a suitably qualified person to explain it all

[chesney]

Simples. I double de-clutch out of habit (always have done).
As you change UP a gear you put your foot on the clutch, into neutral, let clutch up, clutch back down, and select the next gear.
Moving DOWN a gear clutch down, into neutral, clutch up, a 'blip' of throttle, clutch down, into gear and back.
I find it makes selecting third when going up a hill much quicker. It's a technique that when mastered makes for smooth gear changes. Ideally, take a ride in a car with someone who double de-clutches to get the right technique.. My AA Book of the car has a very good explanation but I've misplaced it
From a child of the mid nineties

[bmcecosse]

^^^^^ Well done !

[lambrettalad]

Only yesterday tried to explain double de clutching to my young nephew his response:
"too much trouble and i don't need it"

[chesney]

^^^^^ Well done !

I try
Comes from driving 40's crash boxes round a farm (and at one point Croft Race Circuit) from a 'young age'.
I 'hope' it saves wear and tear on the box, I've already destroyed a 950 gearbox with a tired 950 (although the box had covered high mileage) ;)

[bmcecosse]

Hahahaha - 948 boxes just fall apart - don't feel guilty about that!