Q: What are the steps involved in inspecting and preparing piston/connecting rod assemblies before engine reassembly for the 1992 Toyota Celica?
A: In order for the inspection process to be effectively performed the piston/connecting rod assemblies have to be treated with the proper detergents, the original piston rings have to be removed from the pistons and new rings have to be put in during the reassembly process. Utilizing a piston ring installation tool, lift the rings out of the pistons without any nick or gouge the pistons. Shave all the carbon buildup starting from the top of the piston using a scrap wire or fine emery paper but never use wire brush that is fixed in the motor as this can cause harm to the piston. The carbon in the ring grove has to be cleaned and this can be done with a piston ring groove cleaning tool, otherwise, one can use a piece of a broken ring with the caution that you must not remove any metal or harm the grooves. If deposits are found,scrub the piston/rod assemblies with solvent and dry the same with compressed air and ensure that the oil return holes and the oil hole in each rod is clear. If the pistons and cylinder walls are not abrasive or badly worn and if the engine block has not been rebored, then new pistons may not always be required, though, it is recommended to change the piston rings always during the rebuild. Examine each piston for the following abnormal conditions; if detected, examine the cooling and lubrication systems-cracks, scoring or scuffing, holes, and burned areas that show overheating or Abnormal combustion. Small pinprick corrosion indicates coolant leakage, which should not be experienced again to avoid its occurrence. Check the piston ring side clearance with a feeler gauge on several points of the groove for each ring, more clearance often means that new pistons will have to be bought. The piston-to-bore clearance is done by measuring the bore size and the piston size and which should correctly fit; if the piston-to-bore clearance is over the specified limit, then rebore the block, fit new pistons, new rings. Twist the piston and rod in opposite directions to test their clearance, if the play is felt then it can be said that the units have worn and need compensation adjustments, perhaps resizing and pins at the automotive machine shop. Connecting rods exhibit bend and twist, do not pull the pistons out unless it is necessary to replace new parts, consulting on pistons removal visit a machine shop. For a 5S-FE engine, using a finger, try to turn the nut on each connecting rod bolt; if one cannot, then using the said diameter measure it, bolts should be replaced by new nuts in case of going round the measurements. Last of all, turn down any 'broken' connecting rods and examine them for crack and damage, as well as centre bearing bores for nicks and scratches for repaired bores; fit new bearings if necessary, including new rods if connecting rod knock necessitated the rebuild.