Just got my baby....and a question already!

[LisaMurray]

Just got home a few minutes ago with the new Prius. Lovin it already, of course!!

Anyway, I had my husband check the oil at the dealership, and (no surprise) it was about 1/4" over the full dot. Both my husband and the salesman said not to worry. When we got home after an hour drive, he checked the oil again, and it is right at the full mark. Two questions:

1. Am I in fact ok? Should it be at the full mark warm or cold?
2. Can you experts give me some ammunition to convince my husband that I'm not just being anal about the oil level? What are the implications of the oil being overfull? I know mileage is impacted, but there's more to it than that, right?

Thanks in advance,
Lisa

[efusco]

The engine should be warm then shut down and let to rest for 5 minutes before checking.

There is a TSB that warns not to overfill...but I can't seem to find it at the moment....someone will.

[Charles Suitt]

Hi Lisa... and welcome to the Wonderful World of Priusi...

In the 2004 Users Manual, Section 8-2 "Do-it-Yourself Maintenance - engine and Chassis" page 282 (probably the same on the 2005) on the right side of the page under a box called "Notice" you will find the comment "Avoid overfilling, or the hybrid system could be damaged." You can also note that on the diagram "Checking the engine oil level" that "Too full" is noted for any level above the "Full Level" mark on the dipstick. Further "If the oil is below or only slightly above the low level, add engine oil of the same type as already in the engine." So, there's quite an acceptable range of oil level in the ICE (Internal Combustion Engine).

I wouldn't be alarmed at ¼" above full but is IS overfilled and it would be preferable to reduce it to at or preferably a little below the "Full" mark. It seems the issue is that too much oil in the engine could cause "frothing" which could reduce lubrication and substantial overfilling has been reported to cause oil to be ingested into the fuel intake area through the pollution valve... unlikely, but has happened, though probably not with ¼" over. Please don't worry a lot, but you are right on the oil level.

One other thing: Did you see a document named "Prius Pick-up Checklist?" or did your dealer give you a copy of their Pre-Delivery checklist. In the pre-pickup document, a line reads: "check that the oil level is not overfilled (takes 3.9 quarts, not 4)"

[LisaMurray]

Thanks for the quick replies! I think he's convinced now. :wink: In fact, even though I said it's probably OK as is, he's going to take a little bit out tomorrow. (Amazingly enough, we're having some snow here in CT, despite spring having sprung over the weekend. Yuck!)

Now to settle in for an evening of manual reading.....

[bshef]

Congratulations.....

Sigh!
I'm still working on getting ours!
Did you mention what your specs were?
(color, package, etc....?)

[prius mdt]

I recommend checking your oil level only when the engine is cold. Preferably first thing in the morning after the car has sat overnight. Here is the reason / logic:

All fluids in your car expand when they get hot. This would explain why your oil level was up when you got home and correct after it sat. If you check your oil level when the car is warm, how warm is it? How much "up" is correct "up" for the temp? - If you check the oil when it is cold, you know it is in the correct place - the variance of ambient temps in the world is smaller than the possible variance in engine temps.

My recommendation for any engine is "full" when cold. My recommendation for prius is either "full" or " a smidgen below full" when cold. Any engine that approaches the "add" mark when cold truly needs to have oil added.

[DaveinOlyWA]

when in doubt, do both i say!!

i have done both and i see no difference in levels. i will continue to test in case the position of the car may have influenced my results.

[jeromep]

My Prius is still on its factory oil fill. It is "overfilled" as you describe yours. Seems that a great deal of the factory fills are this way since you and I are not the only ones that have discovered this. I do not believe that you should drop any oil out of your vehicle right now. Run it as is. The level you see isn't detrimental as it stands, but indicates that even Toyota doesn't necessarily follow their own advice.

A dipstick is not a precision device. Therefore if your oil level is a bit over the dot on your engine (no more than about 1/4 inch), the same volume of oil placed in another Prius might show that the engine is filled to the dot, which is perfect. That same volume of oil might also show up in another as slightly below the dot.

When you go in for your first oil change, this situation can be corrected. But it is not a major issue right now.

[cpwaites]

I had the same overfill problem. I took mine in at 400 miles (also for an alignment and minor trim problem) and the service tech was "shocked" to find that the oil was overfilled. They drained it and refilled to the proper amount. Equally important to me, if in fact the past overfilling does lead to a problem down the road, I have a record of the problem. It would be a good excuse for an early change to synthetic as well, though I did not.

[LisaMurray]

I had the same overfill problem. I took mine in at 400 miles (also for an alignment and minor trim problem) and the service tech was "shocked" to find that the oil was overfilled. They drained it and refilled to the proper amount. Equally important to me, if in fact the past overfilling does lead to a problem down the road, I have a record of the problem. It would be a good excuse for an early change to synthetic as well, though I did not.

You must be thrilled to have a service person who recognized that overfill was a problem without you having to point it out to them! A real keeper!