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Ok so I finally have an RB25DET sitting in the garage waiting patiently to be installed into the ceff... The wrecker I bought it off had reason to believe it had been sitting for maybe a year, some of wich was outside not under cover. It's also unclear to me if the engine was properly sealed i.e inlet and exhaust plugged up.

When he first did the comp test the engine was hard to initially turn over, then showed some irregular results 145-165.

After a few more rotations it showed 165-170.

My questions are these-

Is it likely that there was some form of corrosion build up in the bores from having the engine sit unused for so long? Will this burn off without any harm to compression? should the engine be 'free' enough to turn by hand?

not good if rain was getting inside the engine, but if the compression numbers are up around where they should be, it must have been fairly well protected. how bad is the corrosion on the motor?

Pull the motor down

Only way to tell.

If it's corroded, it's a bad engine, basically, throw it away.

My uncle bought a 1UZFE and couldn't bore it enough to get rid of pitting that the water did to the engine.

I'm not really worried about actual water droplets getting into the engine... More so that it was left to 'breathe' if you will. There is a little bit of that white chalky corrosion on the aluminum parts like the inlet manifold and front cover on the turbo.

What would the reason be for the initial comp test yeilding bad results, and the second one very good results? Crud around the top of the piston and rings?

Am I worrying too much? lol

was the compression test done with the motor hot? compression tests cant be done on a cold motor as the readings are inaccurate. has to do with the expansion of the metal rings, pistons and block. May be why the results varied....

initial ones prob had no oil presure, then slowly as it built it got more *relative* if you will, either way i bought an rb20 in such condition, held just under 200rwkw awsum compresion, unless there was actual water in the bores and left to fill up/sit there with it in, i doubt you will have much troubles.

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