I recently had my Prius in for the 20k oil change. I requested that the techs not overfill the reservoir and only use 3.9qts of the four quarts of synthetic oil I supplied. Dutifully, they did just that and there was a bottle with the remaining unused oil. I checked my oil level today and noticed that the level was just over the top marker. The engine was cold, however, and the manual says to check the level with the engine at running temperature. I've heard caveats about overfilling and damaging the hybrid system, etc., but I can't figure out how there could be too much oil unless the dealer didn't completely drain the tank prior to refilling. You techies out there have any feedback? There must be some leeway built into the system here....and why would the oil reservoir only hold 3.9qts rather than four? If the system was based on liters, i.e., four liters of oil, then we would have something like 4.3 quarts to fill it up. Thanks, p.s. planning a drive to Portland tomorrow and thought I'd check my oil again when the engine is warm but the oil has had a chance to drain back into the reservoir.
That's still too much, IMHO. Keep in mind that the safe fill is anywhere BETWEEN the marks on the dipstick. A new car that's not burning oil doesn't need to be filled all the way to the top and no car should be risked all the way down to the bottom mark. 3.5 quarts is perfect.
priusham is right,Bob. 3.5 qts is just right. That is what I put in them here at work. My opinion of the difference is that the 3.9 must be a dry fill,such as if the engine was dis-assembled and no residue was left anywhere in the engine. Since the vehicle is in the shop (warm) getting an oil change here,I put 3.5 qts in,start it up (may have to touch gas pedal to make the ICE come on ) for a minute or so to circulate the oil,then power down and leave sit for about 5 minutes. The level is usually at or just below the Full mark. As for the hybrid or ICE being damaged from the slight overfill,that is false. If the oil is over filled by a lot or has the wrong viscosity (or any number of other causes),this may cause the ICE to be delayed in starting when told too. This would turn on the Check Engine Light and the Engine Did Not Start code would be stored. This is stored even if the ICE does start. The ECU wants to see the ICE start within about 5-7 secs. If it does start but takes,lets say 10 secs,then the Check Engine Light will come on and a trouble code will be set.
Oil sticks to the inside of the engine. You'll die of old age waiting for all of it to drain out. Adding 3.0 quarts works very well. It leaves the level just about halfway, and there's no partial bottle of oil left over to fool with. (Golly, almost as if the designers planned it that way...)
I'm with Richard: 3 U.S. quarts works perfectly, very slightly over halfway between the Add and Full dots. If you use 3 litres, around 2/3 up past the Add dot. After a lot of piddling around, I found it takes 3.35 litres at an oil change to put the level right on the Full dot. I don't think 1-3 mm past the Full dot will harm anything.
Thank you for explaining how that works. I knew that it could set an error code but not why. I got a pump at CRAP that fits down the dip stick tube and you can pump out the extra. It was under $20.
. I got a pump at CRAP that fits down the dip stick tube and you can pump out the extra. It was under $20. [snapback]199692[/snapback][/quote] How about replacing the oil drain plug with a Fumoto valve. Then all you would have to do is open the valve for a couple of seconds. You could even have it drain into a measuring cup if you wanted to be exact. Kathleen
How about replacing the oil drain plug with a Fumoto valve. Then all you would have to do is open the valve for a couple of seconds. You could even have it drain into a measuring cup if you wanted to be exact. Kathleen [snapback]201678[/snapback][/quote] Yes but that requires getting under the car. You can do the pump thing from above. No crawling, no dirty floors, no dripping water, open the hood, put the tube down and pump.
Hi All, just got my 2005 Prius's oil changed at Toyota dealer and despite requesting "please don't overfill it" the warm oil level reads a half-inch above the full mark. My question is: is this too full to ignore?
Yes. It's a good idea to remove it. I went to an auto store and got a cheap siphon for about $2. The siphon itself wasn't so hot, but the tube was exactly the right size. The last time I got the oil changed I gave them 3 quarts and told them I'd add the rest. Good thing, the manager was surprised I wanted to put in so little because the Prius took 5 quarts. :blink: He did ask another mechanic right away and found out he was wrong.
Recently had 5000 mile oil and filter change. Oil level ended up about 1/4 inch above the full pip. Service manager said it was no big deal and I sort of agreed. This morning I drained the oil to about 1/4 inch below the full pip. After a 8 mile warm up, I stopped, reset the MFD to zero, then went out on a rural road for 5 miles and turned around and came back to the starting point. The MFD showed 66.3 MPG. This was with cruise control set at 45 MPH, no traffic. Then I poured the excess oil back in and reset the MFD to zero. I repeated the out and back at the same 45 MPH with cruise control and no traffic. When I got back to the starting point the MFD showed 63.8 MPG. I was surprised, because I did not think that oil level would have made any change. This test was accomplished in less than an hour and there was no significant weather changes. Ross
Hi Ross, A great experiment. How much oil did you drain out: 1/2 quart? After you take the same amount of oil back out again, it would be interesting to see whether you still get 66.3 mpg on your 10 mile round-trip (in other words, what is the variability associated with repeating your experiment.)
Patrick, You are correct, I did drain 1/2 quart. Today (the next day) I drained the oil again to 1/4 inch below the max level pip. I drove the same test route and got 65.2 mpg. Today the air pressure is a little lower than yesterday, the humidity higher and the outside air temperature only one degree (F) hotter. BTW, that is no way near the mpg's I normally get. Ross
Thanks for the info everyone. I had my oil changed at the dealer this week and they way overfilled it. I had to siphon .5 qt just to get it to the top dot on the stick. I was easy enough I may siphon .25 more. G
