Prius Ran with no Oil for 4 to 10 miles...What Damage was done?

If they just put the plug in a bit (hand turned) so as not to lose it but never actually fully tightened it, it would have started a slow drip until it fell out.

My question is what happened to the plastic shield that conceals it, or is that not something on this model year Prius?

 

I guess that the plug was replaced but not tightened, and eventually fell out two days after the service. This seems most likely to me because the extra quart 'poured out.' It would not have taken two days to reach empty if a plug had never been in place.

Etc(SS) gives excellent advice above. I would demand free engine replacement if oil consumption is shown by dipstick to have reached the lower nipple in less than 5000 miles between oil changes before 200k miles on the odometer. The contract should be transferable, and have no ifs,and or buts.

'Bulk,' it seems likely that eventually you will have an oil consumption problem. Do yourself a favor and adopt these behaviors:

1. Check the oil twice weekly for the next month, and then monthly for the life of the car.
2. Impress upon your wife the importance of stopping IMMEDIATELY if the oil light flashes.

 

Take a look at the underpanels, see if there's a lot of oil coating them, downwind from the oil pan.

 

I would try get some documentation from them, acknowledgement of what happened. There was a similar thread here, not sure how to find it. In his case I believe there was more obvious damage. But paramount was to get something on paper from them, clearly stating what they've done.

 

Their message is not what you want to hear and get in writing. Any degradation in engine performance before 200k miles is on their dime. That, or they can replace your engine today.

 

See if you can get in writing their repeated assertions that low oil pressure will cause fuel cut-off. I tried looking the through the repair manual, looking for relevant phrases, without success. (That's not necessarily conclusive, the manual is a real mess.)

I also just Google-searched it, and prevailing sentiment seems to be this is NOT the case, that the danger from fuel cut-off outweighs a toasted engine.

There's also a suggestion, to try disconnecting the oil pressure while the car's running, see what happens. Maybe some brave soul can try that.

^ Trouble with this, you'd probably be left with trouble codes, or worse.

I don't think these guys are on your side. They seem to be trotting out everything that paints THEM in a good light, no more, would pay to be cagey.

 

Very diplomatic

 

Just put the fresh oil and drive. If there is no knocking or anything like that, there could be no damage at all. Monitor the oil level. You can always start the repair process..

 

There have been oil companies touting the benefits of their synthetic oils. Some have drained and ran the engine without oil. If it didn't seize, I think you may just be fine. My brother-in-law showed me that his Civic had no oil on the dipstick after an oil change at the dealer. I asked him if he'd like me to take him to the store to buy some proper oil. He insisted on driving it like that back to the dealer. I think if what was left was still coating and doing it's job/not seized up, you're probably fine. Nice of them to say they'd make things right. It's better if that's in writing. Was it put in writing?

MT2L03 ?

 

I still don't particularly like the response by the shop.

I don't know if I agree with the assertion that any damage done by your vehicle being run without oil will show up "sooner rather than later". All engines wear out with use, even with regular oil changes and NOT running without oil. Your's was run in an abnormal condition for X amount of miles and time. I suppose the only way to "prove" that damage was done because of this happening would of been if you ignored the condition until the engine did seize and totally fail. But you did not.

So you're left with a running and functioning engine and vehicle that has suffered some degree of unnecessary and premature wear due to a shops negligence and mistake.

Unfortunately as I said earlier, I think ascertaining the amount of damage done or possibly done, very difficult. Could you drive The Prius for the entire functioning life of the vehicle or for your ownership period with no real ill affects from this incident? I think that IS possible.
But I also think it's possible that 12, 18, 24 months from now you could start experiencing problems related to a engine that is wearing out. And at that point, you're driving a high mileage vehicle anyway, and proving that the problems have any connection to the incident today would be near impossible....even if that connection IS valid.

Frustratingly also is why the shop continues to try to sell you the myth of a low oil shut off for the gasoline engine. Totally bogus.

I think ultimately it comes down to what remedy you would/will be happy with? Inspection, Oil Analysis, reassurance that your engine is NOT about to burst into flames or seize up? Is that enough for you?- It might be all you can get.

The shop is being "helpful and cooperative" because I think they know they made an obvious mistake and HAVE to be. But I still wouldn't be comfortable with them doing the analysis. Seems akin to asking the Fox to determine the weakness's of the Hen House. They may offer to do a whole lot of things, BUT ultimately they don't want to discover any damage, because it's not in their best interest.

 

The engine is not dead, but that does not mean it will avoid a shortened lifespan.