300 TDI Engine knock / misfire

hi, having aloud noise coming from engine. I have cracked each injector open and found number 3 made no difference, So removed glow plug and found it oily . Suspected injector to be faulty and swapped injector 3 with 1 and tested again by cracking injector pipe and problem didn't move with injector???
having checked oil fill cap for back pressure and dip stick tube l don't think its a head gasket.
Next I opened Rocker cover and No it's not a snapped rod

have you checked tp make sure all push rods are moving there full stroke as they can wear through follower.check vac pump its common for them to fail

jamesmartin said:

have you checked tp make sure all push rods are moving there full stroke as they can wear through follower.check vac pump its common for them to fail

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hi, thanks for your reply, How can I check full stroke on pushrod, Could you explain how to check vac pump? I pressed on brake pedal then started engine and pedal traveled about two to three inches
thank you again
.

watch rockers to see that each looks to travel the same and or excessive free play remove vac pump and check plunger

will check tonight and let you know thanks

hi, done Valve clearances and it sounded a little bit better but still misfire on cylinder No 3. Sorry didn't remove vac pump but found good vacuum when removed pipe and no signs for oil also because knocks aren't my concern.
Took it to mechanics today, lots of white smoke, they both think it's a good chance for an internal fault. So drove home and parked got to strip head off to check for burnt Valve or worn piston. thanks for your help

Hi
have removed cylinder head yesterday and found burnt valve :doh:
no damage to engine block, do you think i can get away with cleaning piston or should i replace with new
cheers

cant see clearly enough ,dont clean piston with anything but degreaser or petrol or such as piston have coating that shouldnt be damaged,if looks alright concentrate on head chances are it burned seat as well.