ive taken my head off to replace my head gasket and noticed theres carbon build up on the piston tops (as expected).
because i dont know how old the pistons are the mechanics at my dads work say i shouldnt scrape the carbon off the tops because it may damge them.
is this definatly true, as i really wanna get it off cuz its bugging me!

 

When I ever take the head off of an engine I always decoke the pistons and valve

 

cant see why scraping it off would damage them??

Go for it, if theres a problem best to find out now than leave it and make it worse surely??

 

Best thing to use imo to remove the carbon is a peice of hard wood....shouldnt mark the crowns in any way then. Afterwards give it a good clean up with a rag and carb cleaner.

Stu.

 

Should be fine to remove the carbon!

once done polishing them is a good move, with very fine emery/scotch pads or similar

 

cheers for the help guys..i should of known better than to listen to citroen mechanics!
gonna go clean them up now,

thanks again.

 

I would clean them only after taking them out of the block. As the loose carbon could fall into the gap between the piston and cylinder bore and then you'll end up damaging the bore...

 

turn the engine over to get each crown stickin out the block and just use fine sandpaper and thinners or petrol to clean em up, then blow all the crap away with an air gun.

 

I asume he is doing it with the engine still in the car

 

what diff does that make? you can still turn the engine over and blow it with an air gun

 

Sorry I didn't understand what you mean by saying turn the engine over?

 

doh! ive just done it but have nothing other than a hair dryer to blow around the edges. it was soft carbon nothing sharp ontop of the pistons but obviously even the smallest bit could damage the walls.
is there any other way to be safe nothing is left round the edges?

cheers.

 

Buy a can of compressed air, should do the trick

Turn the bottom end over a few times aswell by hand and see if anything comes out from te sides.

Have you polished the pistons up? This will greatly help to stop carbon sticking to them

 

ah cool.. im off to halfrauds now, they should do it.. if not b&q etc?

i removed the carbon with the edge of a piece of soft wood, then cleaned them up with petrol and a rag, theyre clean with nothing left on them.

not polished them yet as i was worried small sharp bits may get stuck in the sides, but now im off to get a can of compressed air il be able to blast any little buggers away

 

PC shops sell it aswell if you get stuck.

Im not saying you've got to get the grinder out on the pistons

Just a scotch pad or similar to put a shine on the crowns

 

off on the push bike in the fog to get supplies now
cheers

 

Can't say i envy you even the tiniest bit

 

ended up getting compressed air canister from maplins Ł5.99

polished my tops up nicely now

compressed air is also great when catching your little cousin off gaurd all evening and spraying compressed air in his face

 

Ł5.99, thats cheap!! Was that a small can?

Well, its not really cheap is it for a can of compressed air but its cheaper than it normally is (so dont waste it )

No pictures of your shiny pistons then?

 

Here you go Safechav to satisfy your needs of all things shiney...my pistons and rods



Stu.

 

Could you of posted a worse quality photo

 

lol yeah they are a tad blurry tbh

 

well i was gonna post up a picture later but now blackcossie has put those gems up i think il just cry now instead

 

I know some people just have no consideration for others

(between you and me they aint that good anyway but shhhhhhhhh dont tell him that )

 

I tell you what..my photo skills could even make your car look half usable Night time, way up close with makro and flash off maybe, just

 

 

yay what a come back...tell you what hows about i show you the door

 

And now you've shown me it, ill show you how to use it.

I win ave that

 

Well thank feck he's gone......proberbly too busy with the kleenex and the link from Marsh to be busy with online banter with me

 

here ya go..
before..



after..



i still didnt want to polish too near the edges in fear of anything getting pushed down the sides, so still looks abit messy

also painted the block face in high temp withstanding metallic gun metal grey was still drying when i took pic

 

That was a job worth doing IMO, they were well dirty before

When you say block face, i presume you mean the outside of the block and NOT the face the gasket lies on

 

noooo i meant the front of the outside of the block!
i just cleaned and rubbed down the part the gasket goes onto

oh and it was a 110ml can of comprassed air from maplins i got

 

I should go into business of bottling my own compressed air from the compressor.

Would be minted

 

Another good way to clean them is get a piece of copper pipe and hammer one end flat on a flat surface, like the end of a vice etc. then use this to get the hard stuff scrapped off. Then use some wire wool with engine oil to get the rest cleaned off. Used this method on my XR2 and it cleaned them up nice, ran well after too!!

Lee