Knocking 4AGE?

[Baxter]

Cross posted from ClubAW:

A few weeks ago my AW11's 4AGE started making a terrible pinking noise. It got worse in a few minutes and turned into an undeniable mechanical knocking sound. Before I parked it up I was convinced a piston or bearing was about to fully let go.

Running it the next day the sound was much less noticeable (ie when cold), so much less my mechanic buddy wasn't convinced it was making a serious death noise the night before.

We did manage to work out it was only running on 3. Popping leads off it turns out number 4 wasn't firing at all. I'm assuming this means either a piston and/or valve has dropped?

I popped the cam boxes off later but couldn't see anything wrong; ie the damn buckets don't allow you to see if the valves are stuck or not. I'd love to know how to work out what the problem is before I lift the head off?

Though I guess at the end of the day whatever's wrong means the head will have to come off any way.

[ee904age]

Drop the oil and check for filings? Should let you know if its a bigend or not. Do a compression test..

[Crucible]

check the cyl compressions, plug colouring will tell you whats up also.

if you want to pin point it, do a leakdown test.

knocking and down on a cylinder doesnt sound too promising though!

[Baxter]

Oil, and plugs - excellent suggestions, ta'.

And yes I'll try and get it to somewhere to do a proper leak down, they'd be great.

Cheers,