Urgent Help Needed!

still sounds like the battery to me. any trouble codes?

 

The drive shaft between the engine and transaxle could be broken. There have been reports of this happening a couple of times in this forum.

 

There is a spring loaded damper that slips and makes the awful rattling while misfiring. It could be broken and has happened before as Brian noted.

If the above was allowed to happen many times as the hv battery drained, the damper springs could have failed. Rare but possible. Even more unusual would be something jamming the engine as a result.

I suspect a very basic fault happened when you took a good running engine and changed coils and injectors. Maybe a pulled wire on the coil wiring harness or a cracked insulator on the plugs. Backtracking then would have been a good move. That problem is probably still there.

I must say that was a good move although who knows what the parts car had for a hv battery.

Codes could tell the story.

 

Put a wrench or socket on the crankshaft pulley bolt and see if the engine can be turned a few revolutions in the clockwise direction. (with everything turned off)
What codes are present (you mentioned VSC light)?

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Transmission in Neutral first?

 

Prius has a funny transmission. It is always inherently in neutral unless the car's high-voltage electronics are making it be otherwise.

When the car is turned off, you can turn the engine easily with a wrench on the crankshaft pulley any old time (unless something is b0rked).

You can't push the car before shifting out of Park, just because the parking pawl prevents that.

 

Why do you feel the engine is fine? Have you tried spinning it by hand?
Your symptoms sound exactly like a locked engine. Saw that only one time when a 2008 was run with low oil until she locked up, and stayed locked up.

 

No. Turning the engine causes MG1 to move through the planetary gearset.

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... which, just to be clear, means you don't have to do anything special first before turning the engine, because MG1 is just a rotor that's free to spin when the car isn't on and electrically constraining its motion.

In a conventional car with, say, a manual transmission in neutral, turning the engine would cause the transmission input shaft and countershaft to turn. So, either way, you're spinning a few extra kg of metal things, but nothing that would make your engine-turning test difficult.

 

True, but the repair manuals all make a point to put it in neutral because manual cars are usually parked in first or reverse. I suppose if the car is up on lift points with the wheels dangling one could still turn the motor in gear, and also turn the drive wheels. Probably not though if it was on the sort of lift where the wheels still bear the car's weight, or on the ground, and the parking brake set.

 

In post #32 I intended to (and think I did) describe "a manual transmission in neutral". When a manual transmission is in neutral and you turn the engine crankshaft, you're also turning the transmission's input shaft and countershaft, but not the output shaft, so the wheels don't have to move. Yes, with the manual transmission it's up to you to make sure it is in neutral first so you can do that.

In a Prius transaxls with the car off, when you turn the engine crankshaft, you're also turning the transaxle input shaft, planet carrier and sun gear, and MG1 rotor, but not the output shaft, so the wheels don't have to move. You don't have to do anything special first, because this 'neutral' condition is the Prius transaxle's natural state, any time the high-voltage electronics aren't making it do something different. (It can, in fact, be in Park, with the parking pawl holding the output shaft from turning, rather than Neutral with the parking pawl withdrawn, but that only affects whether you can roll the car, not whether you can turn the engine.)