For engine washing, after disconnecting all the valves, bolts or motor mounts, other exterior hardware and every single wire switch or sensor on the block must be detached. Strip off any of the sealant on the cylinder block and the crankcase but should not harm the gasket surfaces. However, if piston oil jet spray tubes are fitted, it is recommended their removal be carried out by a technician to prevent damaging them. All the oil gallery plugs should be pulled out while on most oils galleries the plugs may oftentimes be hand tight and may need to be drilled and retapped; fresh pins should be used once again. In cases of highly dirty castings, the best way is to use steam-clean or a proper degreasing agent while for slightly dirty castings, clean with hot water mixed with a little soapy water and then use a hard brush. Following the cleaning, be sure to rinse the oil holes and galleries with warm water until clear, and then thoroughly dry and dope the cylinder bores with a light film of oil to keep off rust, preferably by using compressed air if possible. All threaded holes should be passed through the correct size of the tap to guarantee the torque measurement in reassembly and any debris cleaned with compressed air. Before closing the new oil gallery plugs, the surface should be sealed with sealant. If immediate reassembly is not going to be performed, then one must cover the engine with a plastic bag so that the mating surfaces and cylinder bores do not rust. For examination, look at the casting for surface flaws and signs of corrosion and stripped threads; you may wish to consult a specialist about internal water leakage in the cylinder block or crankcase. Every cylinder bore for scuffing, scoring and wear ridges and the bores must be taken to the automotive engineering workshop for measurement. The cylinder bores and pistons usually require reboring or reconditioning if the above measuring is out of limit if it is within the accepted limit it is only the piston rings that may bad and require replacement while honing of the bores for the proper bedding in of the new rings can be done an engine reconditioner at a moderate cost.