well i was wondering what the easiest way of checking the big end bearings? and i assume the way to check them is to take the cylinders off and check the conrods for play? i was just curious if there was an easier, quicker way, although i dont really see how there would be.. also, can you change the big end bearings without splitting the crankcase? because i dont think im quite competent enough in the flat 4 for that right now!! any thoughts would be appreciated you wonderfully helpful people
Only real way is to take the heads/cylinders off, undo the conrods and inspect/measure the journals. Never done this, but I'm told it's possible without splitting the case, with a bit of cardboard to catch any stray nuts. Zed will know. Why do you think yours are duff?
thats what i thought, thanks man. well at first i thought it was the tappets/rocker clearances, but the knockings got a hell of a lot more significant in a short period of time, and its only been run for very short periods of time, and not actually driven. so i think its got to be something more unpleasant than that. so i had a guy from a nearby aircooled garage come out and have a look at it last night, and he said he thought it was that, or the small end or conrod bearings.. bearings of some sort anyway. and as i have a set of new big end bearings in the box of nice new shiny things that got delivered yesterday, thought it couldnt hurt. although if i have to split the crankcase, il probably get someone else to do it, but given my current monetary situation, i think that wont be for a while...
Have you taken the rockers off and checked everything is ok? It is possible to change them in situ. The problem will be if the crank is scored where it has been knocking, If it is very mild you can scotchbrite it out. I don't know how you would do this complete though as any bits you do manage to flatten will probably end up in the case. It is worth a look though. If your lucky it will be the small end. Did he say what side or what piston he thought the problem was ? Did he check the oil pressure? If it is a big end bearing failure the pressure would drop.
no i haven't managed to get under it today, got some bad news last night so spent most of today dealing with that. and no, to be honest the actual response i got from the actual dub guy was unclear, he wasnt really sure about it. it was his mate that was with him that was convinced it was an inside the crankcase thing, but he kept making comparisons to motorbikes, so i wasnt entirely convinced, although i know the theory is similar. the vw bloke checked loads of things, and seemed to conclude he didnt know what was going on. although he did confirm what i thought, which was getting all of the wiring ripped out and completely re-done, will be necessary in the not too distant future, the electrics work, but have been done by some sort of retard. i thought it was knocking from the left hand side (when looking from the back) originally when the knocking was quieter, which is why i put it down to a problem with the head, which also made sense because the rocker cover gasket was knackered, and was leaking oil. so it would make sense that something was wrong there, i thought. i have replacement heads, although they definately need a clean. also have new pistons/rings/cylinders/gaskets/pushrods etc. so i was prepared for pretty much everything.. outside of the crankcase!! i have a new crankcase and internals, but they are 400 miles away because i couldnt carry them. so im currently not sure what i should do next, as i have pretty much exhausted my funds for now. would anyone care to take a punt at the next step? any input would be awesome, cus im currently a bit at a loss...
Get a stick against your earlug and use it as a stethoscope against various parts of the engine to locate the noise. Why buy all those new bits before you've found out what's wrong?
Also get a length of garden hose or similar and use in same way to listen for exhaust leaks, they can sound very clattery.
