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1999 Impreza OB 2.2L Head Job after blown timing belt

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OK well the timing belt that broke indeed lead to some damaged valves. I've been following the shop manual and everything seems to be pretty much to a T, except one header bolt came out. I've been taking a bunch of pics and will provide a link and full description when I get the time.

 

Anyway, attached are two photos of the tops of the pistons. For 180K it seems they have nice carbon build up.

 

I figure to clean them off, any suggestions on what to use?

 

Do any of these pistons show signs of other problems?

 

Also the bolt for head 2-4 lower right (letter B in the manual) was completely covered/corroded perhaps some water leaking into that area? A typical 2.2 thing?

 

1999SubaruImprezzaOB029.jpg

 

1999SubaruImprezzaOB028.jpg

 

1999SubaruImprezzaOB027close.jpg

I use a very soft bristle wire brush wheel in a drill to clean the piston tops. Bring each piston almost to the top, you can run the wheel over hte piston top, keeping hte bristles inside the cylider walls. A soft wire wheel won't harm the cast iron cylinder liners. Just be very careful not to let it *jump* and run across the surface of the block. Also make sure not to nick the edge of the cylinder with the drill chuck.

 

Some of the head bolts extend into cooling jacket, so some rust on them is normal. Use a dab of RTV on the very tip of them to prevent this in the future, or just don't worry about it, it's fine.

looks like every one i've ever pulled with similar mileage. i've cleaned them a bunch but frankly i don't know if it's worth it. i think it's more of a mental exercise because of what they "look" like, but the actual difference you're making is almost non existent. any non-smoothness, meaning residual stuff or added scuffing from cleaning, on the pistons probably accelerates build up which you'll have again in no time anyway.

 

glad those pistons look good, hope it all goes together well.

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