Real issue, or bad shop?

did you check the oil level before towing it into the shop?

 

what kind of maintenance have you done to it and at what mileage were they done? It does seem like a coincidence to have it break down 90 miles after the services.

 

If you've maintained the car and oil changes as scheduled (even though you are late on the spark plug changes), then you should go get another opinion. The engine if maintained properly and well lubricated, should not have MAJOR issues at 150k.

 

The "cylinders" never move, they are part of the engine block. If they mean that the piston isn't moving within the cylinder then yeah that is a pretty severe failure. To be honest that would normally make a bit more noise than just a rattle. Did you get any warning lights before the rattling started?

Anyway, it's probably worth getting a second opinion on what happened to the engine. I'd be tempted to get it towed to an independent workshop and get them to take a look.

 

Highly unusual, It sure sounds like they made a mistake.
I would gamble and tow it to another shop to see if they can figure out what went wrong.

 

maybe they dropped something into the cylinder when changing the plugs.

 

This seems pretty expensive for a car with 150k miles and may need a new traction battery in the near future. You might want to get another opinion on the damage, hoping for a cheaper fix. A new engine and traction battery will run over $5000, not sure it's worthwhile for you

 

The first thing that comes to mind, similar to Bisco's comment, is that grit got into the cylinder during the spark plug swap. If the caps over spark plug wells are not effective, stuff like sand can accumulate in bottom of well, pretty disastrous.

If this was the case, could it be proved with scope inspection??

 

Take all the spark plugs out and take a look. That's easy enough to do. Iridium or copper wouldn't cause what you are experiencing.

 

Have the mechanic you trust look it over, the regular gas engine is no different than any other car engine. take the spark plugs out and see what they look like. Maybe they weren't installed correctly, maybe it's broken. Nobody knows until you start digging deeper.

 

FWIW, you may find it will be just too much expense to fix your car. Maybe you should just call it a day and invest in a newer one. Normally, the engines last longer than yours did. They might have got some grit in the cylinder when changing the plugs. Who knows. But if a rod is broken, and no piston movement... It would surely be more than a rattle. More like a big bang and a hole in the side of the block.

I would seek a second opinion. Trust the guy who you normally would. Heed what advice you feel is worthy here on Prius Chat. IMO the figures you quoted are too much for the age and miles on your car. If it was mine, I would get something different and not waste any more time or money on it. Also a used engine with close to 100K on it is almost 2/3 wore out. Definitely not worth the money you are talking. Toyota says the lifetime expectancy of the Prius is 175,000 miles. Consider that and where you are now.

Ron (dorunron)

 

It is time to gather some facts based upon observation, rather than continue to speculate.

1. It could be that the issue is a failed spark igniter or fuel injector for cylinder 2 causing the misfire. If so, that would be a relatively simple repair costing three-digits.

2. Remove the spark plugs and turn the crankshaft pulley by hand (using a socket wrench or a box wrench on the pulley center bolt) to see if there are any abnormal noises or if you have difficulty as you rotate the engine. If you can easily rotate the crankshaft, there is hope that the engine mechanical condition is basically OK.

If you have a problem rotating the crankshaft that would lend credibility to the hypothesis that a piston connecting rod is broken. For example if a piston is stuck in the cylinder due to a broken connecting rod then you would expect that the valves would hit the top of the piston as you rotate the engine, or the broken connecting rod would hit something as the crankshaft is turned.

As the crankshaft is rotated you can use a long narrow screwdriver or other probe to insert into each spark plug hole to gauge the distance to the top of the piston. That distance should vary as the piston moves up and down within its cylinder.

3. If the results of #2 are favorable, have a cylinder leak down test or compression test performed on the engine. That will show whether the engine is in basically good condition or not. If not, then have a used engine installed. The compression test requires access to Toyota Techstream (or the Mini VCI clone available on Amazon.com)

4. Look on eBay for used Prius engine prices which will be lower than $870.

All of the above steps can be performed at home assuming you have the correct tools and know what you are doing. If you don't then ask your mechanic friend for help. Even if he doesn't have Techstream he should be able to perform a cylinder leak down test, that requires rotating the crankshaft to top dead center (TDC) to check cylinders 1 and 4, then rotate the crankshaft 180 degrees to check cylinders 2 and 3 (cylinder firing order is 1 - 3 - 4 - 2). The entire firing order is performed over 720 degrees of crankshaft rotation so when the engine is at TDC, check cylinders 1 and 4 to see which one is in the compression cycle (the other will be in the exhaust cycle where the exhaust valves are open. Then rotate the crankshaft 360 degrees which will reverse which cylinder is in compression cycle and which is in exhaust cycle.)

 

At the very least, a 2nd opinion is always a good idea.

I've had an engine "lose" a cylinder before - the connecting rod broke and the piston no longer moved. It sounded AWFUL. Rattle would be a severe understatement. Plus, my dash lit up like a christmas tree and I instantly lost oil pressure, even with it running knocking and banging (This was on a different vehicle, NOT my Prius).