My type 4 1800 twin carb engine has developed a knock, ive got no idea what it is....

Its not big end but maybe a lifter on the way out? Cam bearings?

here are two audio's of the engine idling.

Click here to watch Knock-2

Click here to watch Knock-1


any ideas?

was planning a trip up the coast (12hr round trip) in 2 weeks....

thanks
Edward

When my 2L in my kombi started knocking my neighbour at the time (John Richardson) from volksworld said that was the end of it. I cant remember what he said it was but i remember the look on his face when he heard it! did you have any loss of power at all? coz i did in mine.

power is fine, oil pressure is about 20psi at idle... then max pressure (60psi) by about 2500 rpm.

Just changed oil and filter on the weekend, no change.

i have noticed that it takes a little longer to build pressure on start up than it use to.

I dont think you will be doing that 12 hour trip in a few weeks

get along to someone who knows VWs and let them havea listen before you destroy too much

took off the # 3 rocker assembly, ran the engine... no change
took off the #4 rocker assembly, ran the engine... no change

check both for wear, they look ok to me, will post a few pics of the adjuster and valve head faces (weird contact)

but then put a long screw driver to my ear and tracked down the noise a little better
checked:
lifter area on 3/4 side of crankcase - no noise
3/4 rocker cover - no noise
oil pump - no noise
sump - no noise
fan housing - no noise

then touched it on the 1/2 intake manifold and could hear the noise very distinctly
did the same to the 3/4 intake manifold but the noise was much much quiet (wouldnt think anything of it)
also doing the above on the exhaust you can hear it, quite a bit fainter than on the intake manifold tho

at this stage im thinking valve train on the 1/2, is there anything i should be looking for in particular? worn valve guides or something?

tonight ill take off the 1 and 2 rocker assemblies and see if there is any change....

what do you guys think? any input greatly appreciated!

sounds like a big end to me

from http://home.arcor.de/silke.fokken/sounds/ 

if you listen to the 'loose con rod' sound: http://home.arcor.de/silke.fokken/sounds/looserod.wav 

i dont think it sounds like that, what does a small end bearing/bush sound like?

take it to a VW mechanic for a face up listen to it

My 1800 camper sounds like that at idle too and that is after a freshen up with new bearings, rings & reco heads after a cam bearing lost its thrust face. The timing was all over the place so at idle it was so retarded it sounded like a tractor! It had been reconditioned not too long ago and all was within wear limits in the bottom end and cylinders. Sorry a bit OT.

I have replaced valves and the adjuster screws and even set at .004 (for testing purposes) and it still taps away on 1/2 side. I think in my case a reground cam and wear in the lifters/rockers has upset the rocker geometry hence the noisy top end.
Now I just live with it It has been reliable.

Post that pic if you can mate.

tried taking off all the rocker shafts and running it (one at a time) and didnt really notice a difference in the tick/knock.

The noise has been around for a while, sounds alot like valve lash but doesnt dissappear with valve adjustment.

At this point im leaning towards small end or piston slap

here are the pictures of the adjusters (notice the contact wear patterns)

#1 Exhaust


#1 Inlet


#2 Inlet


#2 Exhaust

# 3 exhaust (pretty much vertical line of contact)


#3 inlet (line of contact from centre to bottom right)


#4 inlet (probably the most deformed, impacts all pretty uniform tho)


what are your thoughts?

#4 exhaust (impacts to the right and below of centre)