Aw sh*t - knocking from intake.

[Oldiebut goodie]

2.5DI F.O.R.D engine
Running the replacement boat engine once fitted I have a slight problem. Knocking/banging from air intake, sounds like one cylinder. I have 3 thoughts, a piece of carp has got caught on a valve seat, sticking valve or burnt valve. Runs well with full revs achievable. Any words of wisdom welcome before I start dissection. (Not easy once the engine has been refitted )
I am going to try running it with the cover off and try to see what is happening.

[nicq]

Endoscope down inlet and turn it by hand, if crap in you will see it.

[Oldiebut goodie]

My thoughts are towards the exhaust valves more but certainly worth a try, got to give that shufti-scope some real work to do. Easier to check inlets as it is a water cooled exhaust manifold which is a PITA to remove whilst in the boat. Just hope that nothing dropped in there during the rebuild even though everything was plugged to prevent that.
One problem though - no way of turning it by hand!

[nicq]

Check tapper clearance to see if a valve is held part open, then you will know what cylinder

[Oldiebut goodie]

Endoscope was useless - it is matt black in there and absorbed all the light, need a searchlight.
Found the the cause though - an exhaust rocker was at around 8mm clearance! Push rod appears to be a couple of mm short without measuring and the facing has been hammered on the rocker arm.
The question now is whether the cam/follower have worn or if the wear is all at the top end and due to lack of maintenance. A couple of other valve clearances are out by the feel of them also. I'll have to just replace the pushrod,valve stem cap and rocker arm for now and adjust it all up and see how it goes. I am surprised that I didn't notice it before though.

[kit]

Is it a fishing boat as I wondered how a bit of carp could get in it?

[Oldiebut goodie]

Yes it is.

[Oldiebut goodie]

Rocker shaft etc. changed - immediate difference! That rocker arm is well sha**ed.
Guilty item:


Knocking gone and a lot quieter, run up to temp and adjusted all and I have a nice quiet, smooth running engine. Cam and follower must be fine as the gap disappeared straight away with the same pushrod and valve stem cap with minimal adjustment needed on all using the rockers and shaft from the old engine. Interestingly there is less wear showing on the old rockers.
Happy bunny again - auntyfoul and relaunch now.

[Oldiebut goodie]

Just the boot top to do and then its time to chuck her back in!

[lefty67]

Just in time for the start of the cod season or is it still a bit early ?

[Oldiebut goodie]

I used to start getting cod at the end of August when I was netting but the main run will be late due to the water temp - it is still far too warm. The whiting are just starting to show about a month late.

[lefty67]

I suppose you'll have to make do with the bass for now