Bottom end failure - 2018 EC300

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Originally Posted by 5valve

Did you measure original head inner oring. Mine was 1.9mm, instead of 1.78mm (from new), which caused coolant blowby over time into gearbox and maybe into crank.

Also, did you have your crankshaft measured for alignment. Mine was at the top of allowable free play, at 0.05mm. I've corrected it to 0.02mm.

Were your cylinder trasfer ports discoloured, darker. (check attachment) They should be aluminum light colour. I'm assuming it could be from antifreeze leak.

Next thing I noticed, was original piston rings having half the allowable minimum ring end gap, 0.25mm instead 0.5mm, So it might have added some extra binding heat to equasion. More heat, more expansion for possible leak. It also made vertical lines on cylinder wall.

What torque did you use on the crankcase bolts 0.8 kg or 1kg? There could also be a crank leak of coolant, in small amounts, but enough to corrode the insides over time. While you think that topping up small amout of coolant after few rides is normal, but it is not, if there is no boil over.

Perdona No entiendo, te refieres a la hendidura del cilindro donde van las juntas toricas?

La alineacion del crankshaft no lo he medido,pero ahora cuando he cambiado los rodamientos otra vez he cambiado tambien la biela y lo han equilibrado.

Si no recuerdo mal los puertos de transferencia del cilindro tenian ese color que dices.

Los anillos del piston tienen tolerancia correcta,y el cilindro estaba en perfecto estado.

Los pernos del carter los he apretado sin llave dinamometrica, pero 1kg-1'5kg deben tener. En caso de haber una fuga de anticongelante, la compresion del motor se iria al circuito se refrigeracion y en ese caso deber?a haber mas presion de la normal en el circuito no?

Adjunto fotos de como estaba el carter y rodamientos con 2000km, el crankshaft estaba igual.