Tapping/Knocking Noise

[simonandjuliet]

Wouldn't a broken crank cause low oil pressure, especially when hot ?

[DavidLaver]

https://www.youtube.com/watch?v=00bduCs07aA

Another idea is to line some spectators up and see (hear...) if its more obvious from outside the car as to what end and what it might be.

David

[DavidLaver]

I know its easy to reproduce on a hill, and four up all the easier so it is load related.  Do I remember right that at some speed on the flat it starts to knock?   Eg on the motorway on the way to an AGM.

Up a hill it wasn't in top...

Try the same hill in - say - second at higher revs and third at lower?

Something else to try is to record it (so as to be able to analyse in the calm and repeatedly) and so tell if it relates to the road speed or the engine speed.

A little camera might tell us more from its sound track - is there more noise from a camera under the fuel tank or hung under the gearbox or under the front axle?

David

[the.cern]

Two things have been noted today ..... the first is that it is now possible to get the noise when stationary in neutral, but only after provoking it by thrashing it up a hill and then only for a short time. Thus it would seem not to be in the transmission after all !!!!!  However, frustratingly by the time I get out and my head under the bonnet it will not perform. Putting it in gear and driving against the handbrake will sometimes get a result but sometimes not!!!  I am beginning to think it is being difficult just to spite me!!

The other thing is that the pressed steel shroud on the tail of the gearbox is loose and 'rings' when under way. However, there does not seem to be any way to tighten it. Indeed, I cannot see how it might have become loose in the first place.

By the way, the speedo cable, once straightened and given a little tlc, miraculously still functions.

Anyway, I will persevere and just drive it until the fault becomes self evident!

                                   Andy 

                               

[DavidLaver]

Book Essex Raceway for a day and drift it round and round until "it becomes apparent".

http://www.arena-essex-raceway.co.uk/drift_practice.aspx

I expect the usual crowd will be well used to tracking down odd knocking noises - even if most are The Old Bill on the driver's window.

Perhaps an exclusive booking for the Appia consortium?  Might be a way for more to achieve that Rat Look.

David

[stanley sweet]

Have you got a friendly local MOT man who could run it on the rollers for you while you have a listen?

[the.cern]

Stanley, that is another option, I may well get to that, thank you.

In the meantime I am playing with the B20, time to get into some serious thinking about rewiring it!!

                          Andy

[the.cern]

Just a couple of photographs showing the gearbox installation.These are after the event. As usual I was so intent on getting the job done that I did not even take one showing the 'box in the cradle on the jack. I will try to do better next time!!

Jim made the cradle. Simply two short sections of channel interlinked and hinged with a bolt. Tilt adjustment is achieved using the vertical bolt . The gearbox sits in the two curved pieces of strip steel welded to the upper channel. The hook projecting from the  upper channel locates into the rectangular opening in the bottom of the bellhousing and the rear of the 'box is simply strapped down. The dowel welded to the lower channel locates in the trolley jack, having removed the cup.

The other photograph shows the car on the blocks and stands, as I said, a little higher would have made a big difference. The piece of ply on a timber batten in the foreground  was the ramp for the jack used under the front of the engine to get the back low enough for the 'box to slide onto the studs.

So, all fairly makeshift but it did the trick. I just wish I did not find it so difficult getting out from under the car and then getting up on my feet again!!! I wonder if its possible to get grease nipples fitted on the NHS, I only want five, that's knees, hips and one in my back !!!!

                                 Andy

PS  By the way, that is the Gussie languishing in the background, one day .......

[simonandjuliet]

Ingenious - patent it !

[fay66]

Ingenious - patent it !

Excellent, very much in the sprit of Heath Robinson

Brian
8227

[DavidLaver]

Two new clues (if I understood correctly at the AGM):

- Has had the noise when stationary.
- On the move touch the clutch and it stops.

The first is not easy to reproduce.  With the second it should be possible to go up a "knocking hill" or get up to "knocking speed" and experiment being careful to keep the throttle down, on the right hill potentially keep the throttle on the floor.

My first thought is crank end float.  Is there a way to check that looking at the front pulley move as the clutch goes in and out?  Is it possible to drop the sump and get a lever in to pry the crank it back and forth?  Is there a "they always go there guv" likely cause?

Would there be something to look for if it was on a rolling road? 

David

[the.cern]

Just to let you know that despite other things going on, this lovely little car has not been forgotten. After the winter's sojourn in the garage it started with little hesitation and has been out several times to get everything up and running again. Needless to say the noise is still there and has slowly worsened with continued use. I am hoping that soon it will be such that I can make a positive identification of the problem before something actually breaks.

With the Y10 causing unforeseen problems, the hunt for B20 engine parts and with the Gussie on the rotisserie having the sills restored it is unlikely that things will move quickly with the Appia, but it is most definitely not forgotten.

                         Andy

[the.cern]

Today there was an opportunity to take the Appia out for a few miles and to listen yet again to the noise. Interestingly, the pitch of the noise has changed, it is now higher. Now it might almost be described as a clacking/clicking noise rather than a tapping /knocking noise!!! Also, it seemed rather more reluctant to appear!!! I just do not know what is going on.

I had convinced myself that there was real merit in the suggestion that the crank thrust washers might have failed allowing the crank to move fore and aft. However, no matter where /how I levered the crank pulley I could not detect any movement. I also checked with the clutch pedal jammed down as I thought the pressure of that on the flywheel might mask any movement, all to no avail.

I am presently scratching my head ......

                                            Andy

[fay66]

Today there was an opportunity to take the Appia out for a few miles and to listen yet again to the noise. Interestingly, the pitch of the noise has changed, it is now higher. Now it might almost be described as a clacking/clicking noise rather than a tapping /knocking noise!!! Also, it seemed rather more reluctant to appear!!! I just do not know what is going on.

I had convinced myself that there was real merit in the suggestion that the crank thrust washers might have failed allowing the crank to move fore and aft. However, no matter where /how I levered the crank pulley I could not detect any movement. I also checked with the clutch pedal jammed down as I thought the pressure of that on the flywheel might mask any movement, all to no avail.

I am presently scratching my head ......

                                            Andy

The best way to check is with the engine running get someone to push the clutch pedal up and down, if there is movement you'll soon see it, and if I remember correctly it will also slow the engine

Brian
8227

[lancialulu]

I still think it is a faulty clutch which from memory did not get changed in the whole gearbox change over point.....