Hi I'm new to prius' and when I brought it from someone they had told me it was only the head gasket. When my dad was taking the engine apart it looked fine but once he started moving the piston cylinder the 4th from the left was shorter than the other ones. Is this normal? Will it cause a problem in the future if not fixed?
Looks like you have a bent connecting rod in cyl #4. And yes, that's a problem. It means that hydro lock occurred in cyl #4 when the head gasket failed (too much coolant entered the cylinder). Time to replace the #4 connecting rod and maybe other parts. Sorry for your loss.
Read up on "Atkinson Cycle" - what you're seeing might be related to that… (…that is if you are quite certain that it isn't hydraulic lock - have you taken your Prius swimming recently?)
The Atkinson effect in a Prius engine is achieved with intake valve timing. No funny business with connecting rods. Pistons 1 and 4 ought to be at the same height there.... -Chap
OK, I didn't realise that - I looked at the animation and was amazed! (…still am!) …thanks for the edification!
