As wierd as this question might sound, im going to ask anyway. I'm about to install my rebuilt cylinder head but I am having a hard time just putting the head on the block with the pistons being this filthy. I attempted to clean them up with MEK but it did not do much. I know that with most high mileage engines the pistons probably look like this but is there any other way I can clean them up a bit? Nothing too drastic tho since I want to have the head back on by tonight.

Thanks.

here is a picture for reference.

 

dont put anything on them while there still in the engine

 

I put a little MEK on a shop towl and tried to see if i can scrub some off, didn't do much so I stopped.

Your saying I should just put the head on like this? I can't pull the pistons off. My goal was to fix a bent valve in the head.

Can I atleast use my compresser with low PSI and blow some debries away?

 

you can try that (the compressor) but when your done put a ring of grease around the cylinder wall and turn the crank manually, this will pick up all the crap that you miss (crap off the pistons) then clean the grease off. dont put anything on the pistons (chemical wise) because i' m assuming the sump is still full, if it is you might contaminate the oil or degrease the bores by accident

 

Well after I get the head back on and install the timing belt and adjust my valves and everything, the last thing I will do is change my oil with a fresh Mobil 1 5W30. Aside from that I don't think im going to try to clean them up anymore anyway, that carbon build up is cooked on there to the point that it would take probably days to just clean a little off.

I'll probably just use the compressor to blow out some debris and crap.

 

I wouldn't worry about how clean your pistons are. However this might be a good time to put some new rings on it.

 

to be honest i've never cleaned pistons other than trying to free the rings from them, its more off a problem on FI engines, they dont like carbon build up

 

Couldnt you spray some seafoam on them, then change you oil ? This is just a thought im not sure if there could be any bad effects from that.

 

Laundry detergent seems to take that crud off ok. It works well on oil varnish too. I have also seen engines sit for quite a while with coolant pooled in the bore, and that loosens the carbon too (but it's not fast).

 

I've just been using steel wool, or in really baked on stuff, a wire brush

 

it does look like you have a lot of carbon/junk build up on your pistons, If you're planning on modding and tuning in the future it would definitely be wise to clean those off, you really don't want alot of build up on pistons like that

 

id worry more about cleaning the head gasket surface than the pistons. unless you plan on a turbo, id leave the buildup on the pistons, it increases CR a tiny bit but i really dont think it will hurt anything on a normal motor

 

Out of curiosity, how many miles does your engine have on it.

 

163,000 miles

 

i wouldn't be so worried about that either. it doesn't seem like you have much on your pistons. it'll just go back to that way even if you do clean it once you get your car runnin. it looks like normal wear.