In case it's helpful, my wife and I posted some DIY instructions for a Prius gen 1 oil change with pictures. The Pan that Can: Change oil on Toyota Prius
Very nice. I was surprised how easy it was to change the oil in the Gen-1. I've been thinking about making a youtube video showing the process so that other gen-1 owners might go ahead and start doing the change themselves, since it appears we can't trust any place not to overfill the car.
I noticed a few issues with your website: 1. You are using the 90915-YZZF1 filter which is not the correct filter. F1 is a bit longer than the correct 90915-YZZF2 filter. Although it doesn't hurt to use F1, I'd suggest that you make note of your choice to use the longer filter. 2. You are adding ~5 quarts of new oil (somewhat less since your procedure involves pouring some new oil through the engine and letting it drain out.) Three thoughts here: - It's not necessary to waste new oil by pouring through the engine with the drain plug open. The residual old oil film is really minor compared to the volume of new oil being added. - Prius crankcase capacity when using the correct size filter is ~3.7 US quarts. Since you are using the larger F1 filter you might be able to use 3.9 or 4 US quarts before you overfill. - Where is the oil level on the dipstick? I recommend that you add a note warning against overfilling engine oil, as this may result in oil pooling in the intake manifold, reduced mpg, and in an extreme case, oil seal leakage. 3. Step 10 says that you put the gasket on the threads where the oil filter goes? The gasket is for the drain plug, not for the oil filter. If you really put the gasket on the threaded stud for the oil filter, you need to immediately remove it as that may impede engine oil pressure.
That kit #90915-YZZF1" has the filter and the drain plug gasket. It's a Toyota part and they just assume if you're using this kit, you are going to dump the oil. So the gasket is "I also believe" for the drain plug not the filter, you should (as Patrick says above) remove that gasket from the filter. Also without the drain plug gasket you will develope an oil leak on the driveway. Do not overtighten this plug! Also for item #10 -before putting the new filter on, prefill (prime) it with new oil about 3/4 or more full, and then with just your fingertip smear a small amount of oil around the rubber gasket on the filter then screw it on. This way the ice will never start with a dry filter, and then you will probably only need the 3.7Qts or so of oil for the ice. Always check the dipstick, do not overfill and always check that the oil filler cap on valvecover top is re-installed. That one's from experience..been there done that. smelled like a diesel.
I just changed the oil, in my Gen 1, using the standard size filter. It did seem like 5 quarts was too much, it was up high on the dip stick, when I checked it. Now I wondering if I should drain some out? will it hurt to have more? Has anyone ran with 5 quarts in the Gen 1? Ok so I went ahead and checked my dip stick again, and its half way up on the stick, So I checked the oil container, and it was a 5 quart bottle, and I added one quart so I had 6 quarts in it. Needless to say I did drain the excess out just now, and it seems that 3.25 quarts is all that is needed. I just read the horror of Walmart oil changes, and I'm glad I decided to drain it down to the right level before driving it anywhere.
