Oil overfill caused complete shutdown

Do you have any idea how much it was overfilled????
What quantity did the oil change place say they put in???

 

"about a half of a quart"

Sounds very easy to do if they just round up to 4 in their heads. I'll keep doing my own.

- D

 

Half a quart overfill will not cause the problems you encountered. Your 12v battery is the most likely the cause. A weak 12v will definitely cause the fluctuations in charge level you are seeing with the traction battery.

 

1/2 quart overfill is trivial, it should not be "breaking" your car. I'd suspect something else.

 

If your 12v battery was borderline and the oil change folks left a door open and/or the radio on while doing the oil change, the battery drained enough to prevent the car form going into READY mode.

 

Nope, the oil was to blame. That is the only way to get those two codes. Frankly, you should not have re-used the oil, since the quick lube could have done something real dumb like put in 15W40.

Charging the main hybrid battery is almost never done at a dealership, and the average one doesn't ordinarily have the charger. Even if they did do it, it is only charged to the point where it will start the car, and not anywhere close to a full charge. I could see them charging the 12V, however.

You could easily lose two bars on the battery gauge if you are sitting at a long stop light with the A/C on full. We are talking about driving in Austin, after all!

If you have a problem with the hybrid battery, you will find a decrease in gas mileage, you will hear the battery fan running (back seat, passenger side) frequently, and eventually you will get the big red triangle.

 

I would say that a dirty throttle body interior was the reason for the two DTC that were logged. 1/2 quart engine oil overfill by itself would not cause the problem.

However, if the fresh engine oil is pumped out of the bulk storage tank at a rapid rate, the oil entering the engine may flow along the baffle located under the valve cover and enter the PCV hoses. Then the oil will enter the throttle body and seep down into the intake manifold below the throttle body.

It is a good idea to replace the 12V battery as a preventive measure, although I doubt it was responsible for the no-start symptoms.

It is unlikely that the dealer charged the high voltage traction battery (because only a very few chargers are available in the US) but it is possible that the tech may have force charged the traction battery after the car is READY. You can do this at home, or anywhere else for that matter. All you have to do is make the Prius READY, then shift into D. Hold the car stationary by pressing on the brake pedal with your left foot. Floor the accelerator with your right foot. You will notice that the traction battery state of charge gauge will move up and as the battery approaches 7-8 green bars, the engine speed will automatically decline.

Since the car cannot move, the power produced by the gasoline engine is routed into MG1 which feeds electrical power into the inverter to charge the traction battery. As this process may heat up the transaxle unnecessarily, I don't suggest that you do this daily.

Regarding what to watch out for, since the OP's car has a high odometer reading, I would recommend that she look at the 100K and 120K maintenance schedule and ensure that all items on those schedules have been performed. In particular, engine/inverter coolant drain and fill, engine/cabin air filter change and iridium spark plug replacement needs to be done. The transaxle ATF fluid also should be replaced if not done in the last 60K miles.

 

Hi prius4gina. Its seems odd that you would get those warning lights straight away as there are no sensors to detect an overfill. I would have thought you would have to a have driven the car around for a bit (and with more than 1/2 qt overfill) before that would happen. Ditto to run the traction battery right down.

Could it be that the oil change guys messed around with the car for some time after changing the oil (before you got in it) trying to get it to start or run properly. If so then perhaps the initial overfill was much larger and they'd already found that part of the problem and drained some.

 

OK, I'm a Prius newbie here, but from what I've heard, over-filling the engine oil (even by as little as half a quart, or filling with too heavy oil weight like 10-w40 with cold temperatures) can cause those exact engine codes. I've heard from technicians that when changing oil on a Prius, it's very important that the person doing it understands that 4 quarts is too much for this engine, and it should never be filled to more than 3.6 quarts.

The reason for the no-start condition is that MG1 has enough torque to snap the crank shaft of the ICE right in half if something should go wrong and prevent it from turning, so if the resolver (speed sensor) on MG1 detects it's not turning as fast as it should be when starting the ICE, it throws a failed to start code, or possible broken crankshaft code and shuts MG1 down to avoid further damage to the ICE. It has to respond pretty quickly to prevent damage because electric motors develop full torque at 0 RPM, so my guess is that it's very sensitive to any abnormal load against the ICE.

Here is a great video I stumbled across the other night that explains the most common no-start conditions for the Prius (relevant info starts about 1:39 in):

 

To Silerts and Babybird.

Op is in Texas. In don't know which part but in Dallas this time of year the daytime temperature is well in the mid 70's. At just 72F a typical 15W40 oil is about twice as thin (yes that's right, half the viscosity) compared to what is a typical 5W30 oil at 32F.

If a 10W40 or 15W40 oil was the cause of this problem then everyone using using 5W30 at temperatures under 50F (at which temperature 5W30 is about the same viscosity as 15W40 at 72F) would be constantly having this problem.

I'm not recommending anyone use 15W40, but in TX at this time of year then that alone certainly wouldn't cause a loss of start. Except for a loss of a couple of MPG you'd barely notice a difference.

Reference (Widman's viscosity calculator) : http://widman.biz/English/Calculators/Graph.html

 

There is no abnormal load on the ICE if the fill is over the full line, not until probably until an inch and a half over or more. The ICE is not very unique compared to others. Even if the crank is touching the oil, which it isn't, except in an extreme overfill case, it won't stop it from turning to snap it. Plus I doubt the motor has anywhere near enough torque to snap the crank. That's just plain nonsense whoever tells a few ounces of oil in the pan over will snap the crank.

The oil on most of these cars came delivered with the oil "overfilled", or not, depending on which way the factory error went, either the dipstick was calibrated wrong, or the oil fill spec is wrong. No one knows which it is.

In this case who knows what really happened at the various shops, it is a rare shop that would tell the truth and admit wrong doing, and as rare for another shop to not find fault and blame the previous shop.

 

I agree with Patrick and Mr.Vanvandenburg. I've had my oil changed and they filled it to nearly an inch above the full dot and I experienced no codes or malfunctions.

 

We'll have to hear back from the OP but I suspect they only witnessed the end result of whatever the previous stuff up (or chain of stuff ups) that the lube shop did.

If she had left it with them for another 15 minutes they probably would have delivered the coup de grace and tried to jump it with reverse polarity. Ok I know, I'm so horribly cynical.

 

Apparently it can't be said too many times: Always check the oil yourself before driving away from every oil change, no matter who does it. You can find all kindsa dumb mistakes before they become annoying or expensive. If someone else does the work, do them a favor by telling them in advance that you will check it before leaving. And then do it.

And, oh yeah: three quarts even is plenty. Try it and see.

 

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