What Is This Noise? Can Anyone Help?

[neilsmith]

My engine has developed a rattling sound that only occurs when at full running temperature and at around 2k rpm with no load on the engine, I don't think it's the bottom end but hopefully one of you guys can help

Just to clarify I haven't driven the car any more than a mile like this I heard it on my way home on Sunday night

Any help appreciated guys!

https://youtu.be/u90ld5N6Wm4

[neilsmith]

Just to add there is a crack in the exhaust manifold which is blowing only very slightly but I don't think that has anything to do with the rattling sound

Neil

[aleximport25]

When I got my v the mani split in two and was only held together by the bolts. I had a very similar noise to yours but I noticed it more cold as when it got hot it expanded and closed the cracks

[neilsmith]

UPDATE;

Measured all valve clearances and results are

Intake;

0.21

0.22

0.22

0.31

0.21

0.23

0.18

0.20

Exhaust

0.35

0.39

0.40

0.37

0.38

0.37

0.36

0.36

It appears that all exhaust shims are out of the 0.3 +-0.03 tolerance

And one of the intake shims are out of the 0.2 +-0.03 tolerance

I'm still not convinced that this is causing the noise

Neil

[neilsmith]

Removed sump and found this on piston 4

[lukEp]

Your lucky. It doesn't look like it's span the shell. 4 is furthest from the oil pump so I'd be changing that as well. Have the crank measured you might get away with it. Change all bearing mains thrusts and big ends as they will all have encounter some sort of wear from loss of oil pressure.

[neilsmith]

Luke you right I think I may be very lucky lol

The oil pump hasn't done any more than 2k miles but there has definitely been a loss of oil pressure somewhere along the line as the oil light was flickering a bit on tick over so I will change that anyway but do you think there could be anything else that would cause a loss of oil pressure?

Neil