big end knocking question..

[Jamo]

this makes un-nerving reading....as my avant is loosing water, not much, but it still needs topping up every other week..and it was just a lose of coolant made you check the compression.....or did you get any other symptoms?
running warmer than usual??....

Yeah but there's a few places that are culprits for water loss

Check the turbo coolant hoses and the two hoses on the side of the block, one for the thermostat and one from the water rail to the turbo coolant inlet.

[newsh]

And the after run pump, and the bottom of the main rad where the mount is.

[Flat on my back]

.

And the core plugs...very hard to see...

[europeanme]

....better have a look, as soon as it has finished it's time as the MOTer's....I might see if the garage will look at my compression...

if it was leaking wouldn't I see some eveidence of water??....

[Jamo]

Coolant system is only under pump pressure with the engine running so you'd have to check on a running engine, carefully or you'll end up in hospital like Rusty!

[europeanme]

thats why I'll get someone else to do it!!!...

[GazzaG60]

those pitting marks are det. the piston seems to draw the det to that flat spot. could be one bad batch of fuel thats all. take car when its hot.

as for the knock. have you removed the cap from the rod. if not take it off and have a look at the lower shell. expect it to be worn in a fairly even manner. also check to make sure you aint spun it.

what do you hear when you rotate the crank?

both time si have had issues i have heard noises like crank knock. my mate has seen a zillion ****ed subaru cranks and feared the worst. first issue was head hasket and cam sensor second issue a broken crank.

what does a comression test say. when the plugs are out and you crank does it sound smooth. if you have no bore damage then id be looking on the bright side.

while you are at it send the pistons in for a clean up. this will compensate for the skimming of the head too. send a set of good aftermarket rods with it and have them weight matched to each piston. i had mine skimmed a little more to give me more headroom. you will have yourself a good clean strong set then. if the crank is damaged it may be repairable.

[avants2turbo]

those pitting marks are det. the piston seems to draw the det to that flat spot. could be one bad batch of fuel thats all. take car when its hot.

as for the knock. have you removed the cap from the rod. if not take it off and have a look at the lower shell. expect it to be worn in a fairly even manner. also check to make sure you aint spun it.

what do you hear when you rotate the crank?

both time si have had issues i have heard noises like crank knock. my mate has seen a zillion ****ed subaru cranks and feared the worst. first issue was head hasket and cam sensor second issue a broken crank.

what does a comression test say. when the plugs are out and you crank does it sound smooth. if you have no bore damage then id be looking on the bright side.

while you are at it send the pistons in for a clean up. this will compensate for the skimming of the head too. send a set of good aftermarket rods with it and have them weight matched to each piston. i had mine skimmed a little more to give me more headroom. you will have yourself a good clean strong set then. if the crank is damaged it may be repairable.

The cylinder head off my car, which is the one im using has not been skimmed, the pistons are all (bar the one with the light pitting on the flat area) in excellent condition, there is not scoring on the bores and no lip at the top of the bore.

I havent removed the block from my car yet, that next weeks job, as the RS2 big end bearings are going to be 7-10 days from Germany!

when i get the bearings out i will photograph them and post them up here.

Presumably to remove the big ends I dont have to remove the piston/rod from the block?

If there is no damage to the big ends then I suppose I have to whip the pistons out and check the small ends?