Oil Overfill--no warranty

you've been hosed. plain and simple. I'd tell the servcie manager that they are a rip off and I'd want to see the code that they pulled to determine that was the problem.

 

Forgive me for asking what might seem like a dumb question, but I assume you changed the filter, too, right? (hey, don't laugh - I've known people who change the oil but not the filter!)

If you didn't, that would account for the extra oil since the filter holds a certain amount. If you put in the 3.9 without changing the filter, you would have ended up with quite a bit more than the recommended quantity.

 

Jackson, I assume you check the level on the dipstick after you added the oil to make sure it wasn't overfilled?

 

My local Prius-certified Toyota tech warned me that if I ever change my own oil, to only put in 3 litres.

Then start the motor (He said select Max Hot if cold, or Max A/C if summer to trick the motor into starting sooner), run it for a minute or so to check for leaks, then shut it off. Here's the important part: let it sit at least 15 minutes on a LEVEL surface.

Then carefully add, no more than 0.5 litres, to bring it up to just below the Full mark.

 

Sheesh! If that's what you have to do to change it properly, then I'm glad I bought the prepaid maintenance plan from Troy Dietrich....my local "speedy lube" would never be able to handle that !!

 

Don't get too smug - there have been numerous reports from owners that the Toyota dealerships have overfilled their Prii during oil changes... ;-)

 

There's no need to fill the thing. The FULL mark indicates the maximum capacity of the system. When you change the oil (and filter) just put in three quarts and you'll have it halfway between ADD and FULL, which is perfect. No fuss, no muss, no danger. And yes, it's amazing how many stories we've had here of Toyota dealer service overfilling.

 

I'm still waiting for my dealer to send me a written statement that, since his tech put 4 quarts of oil in my car last oil change, it was OK for me to continue to do that and have warranty coverage.

Like I say, I'm still waiting to get it in writing, 5,000 miles later...

 

Can someone explain to me how oil backs up into the manifold? Is there somewhere I can find a picture of the engine cut in half? I assume there is something different here and I'd like to understand.

Thanks!

 

popsrcr, My Prius tech told me it's due to all the different valves and pumps that works with the hybrid system. Don't know if he was blowing smoke up my..... or not. I didn't understand too much what he was saying so i just nodded LOL. But he did know it was important not to overfill the oil and he never has so I assumed he knows what he's talking about.

 

Well, I've heard this several times now, so I have no reason not to believe it, but I'd just like to understand it. My knowledge of a "normal" engine would say this isn't even possible. I mean, there isn't anything to lubricate in an intake, and you aren't cooling either. So, I assume there is something different going on. Until I can see a cutaway, I guess it will remain a mystery.

 

Some motors can be more sensitive to oil overfill than others. To control oil vapor emissions and to keep the motor internals clean, the PCV (Positive Crankcase Vent) system was developed.

Engine vacuum draws the oil vapors into the intake where they are consumed in the motor. If you dramatically overfill the oil, there will be a lot of foaming, as the connecting rods will be splashing through the oil, which will cause excessive oil to appear at the PCV. In some cases the PCV system will fill with oil and then the motor will gulp it in.

My 2000 GMC Sierra had a TSB for the PCV valve. The design originally used on the Vortec 5.3 caused excessive oil consumption, as it kept such a high vacuum on the motor it sucked up normal oil levels. The redesigned PCV valve dramatically lowered oil consumption, at least in my case.

I do know with my Prius, I've only had it long enough for one oil change. The Prius tech was very, VERY careful when he refilled the oil. They don't promise a quick oil change with the Prius, they prefer you leave it an hour.

 

<div class='quotetop'>QUOTE(jackson5\";p=\"61154)</div>

If you changed the oil and filter and put in no more than 3.9 quarts, I can't imagine there could be enough extra to be throwing much oil into the manifold.

Wouldn't running it LOWER the level on the stick since you have now distributed the oil through the filter and engine? It would seem impossible to have overfilled it if the answer to this question is 'Yes' and it was AT the mark when you were done.

 

Jayman - Yeah, I know about PCV, but it would have to be dramatically overfilled, I would suspect, for oil to be splashed by the valves in enough quantity for a negative effect.

Its the whole "oil in the intake" thing that gets me. How could you possible get enough in there to matter?
This isn't a big deal to me, I always put in 1 quart less, start the motor, then fill up. I just really want to know what the big deal is. Everyone makes it sound like the worst thing in the world.

 

<div class='quotetop'>QUOTE(popsrcr\";p=\"61156)</div>

please Post it if you have info. If you checked your Prius when you first got it you'll have found that the level was 1/8" over the full mark. 4 liters is what Toyota probably used for a factory fill. All the Toyotas we get are about 1/8" over full, brand new.

 

Well, as far as PCV design, I do know my 2000 GMC Sierra had a serious problem with oil consumption. It didn't matter if the oil was at F or L, the PCV valve allowed such strong engine vacuum that even with a motor not overfilled, it sucked oil out of the head before it had a chance to drain back down.

A redesigned PCV valve cured it, and also introduced an annoying whistling sound. I think I preferred the oil consumption, that whistling noise was at just the right pitch to drive me bucking fonkers, it even attracted dogs.

Some motors are much more sensitive to oil overfill issues than others. Without a shop manual (Those usually have a nice cutaway of the motor) I couldn't say what the deal is with the Prius motor.

All I do know is that my Prius-certified tech claims this motor is very sensitive to oil overfill. Either the crank rods are hitting oil or the PCV is sucking excess oil vapor. Something is up here.

BTW: mine was delivered with the oil level slightly below F, about 2mm lower. It was never past the F mark.

 

I had a rough idle when my '97 Nissan Sentra was cold, and oil was found in the air filter and Mass Airflow sensor. PCV circulation was leaking through both ports. Dad thougth it was the PCV valve, as it was old. Replaced it, same problem. I suspect my problem was too much back pressure due to a clogged catalytic, esp when the computer was signalling a bad cat.

My '88 Honda Accord had an oil consumption problem, and rough idle. That definitely turned out to be a PCV valve that was wide open. Replaced that, no rough idle, no oil loss.

I suppose if the oil is too high, it could end up in the intake through the PCV system.

 

I just got back from the heated underground parking, where I spent a lot of time with a flashlight. It does appear to me the PCV port could introduce oil into the intake manifold if you happen to add fresh oil too quickly.

I don't think this has anything to do with how much you add past Full, unless you dramatically overfill the motor. Then any motor will be damaged.

It could be the return oil passages in the head are sized ok for normal operation, but suddenly dumping in 3-4 litres of oil at once may allow the oil to back up. Once it enters the PCV system, you could have oil introduced into the intake.

I don't think you will have this "problem" on most V6 or V8's, like the 302 in my old Ford F-150. The PCV valve is at the highest point of the passenger side valve cover, and the oil fill is on the driver side valve cover.

On a 4 cylinder motor, there could be more of an issue. Frank Hudon mentioned this same problem on servicing Toyota forklift trucks. I suppose the best way to avoid this is just to take your time refilling the fresh oil.

I was worried about this issue when I first heard of it, as I thought the motor was extremely sensitive to operating oil level. After closer inspection of the head and the air filter box, this appears to be non-issue as long as you are a bit more careful with how quickly you refill the fresh oil.