Generation 1 Oil Change; Need new gasket / special wrench?

Yes, Toyota requires that the oil drain plug gasket should be replaced each time the drain plug is removed. I buy the gaskets in qty and routinely replace them after each change.

Whether gasket replacement is "necessary" depends upon whether you care about an engine oil leak, or not.

If the oil filter is mounted very tight, then yes, a cap wrench is necessary.

The spec when tightening the oil filter is 3/4 turn after the gasket contacts the engine machined surface. I usually tighten the filter 1/2 turn.

 

Good observation. It is certainly possible that the quart bottles are overfilled.

The Prius engine can operate with the oil level anywhere between the top and bottom dipstick dimples. The reason that you might want to fill the oil level near full is if you want to have some reserve in the event the engine starts to consume oil and you are not in the habit of frequently checking the oil level.

I usually fill 3.75 qts and the oil level is ~1/8" below the top dimple.

Another issue that affects oil level is how much effort you exert and time you allow to drain the old oil. I have found that after removing the drain plug, if I lower the right (passenger) side of the car while the left (driver) side remains elevated with a jackstand, that more old oil will drain out.

You are supposed to continue the draining process until you see only one drop per minute or so, but I am not patient enough to wait that long.

 

One trick is to start the drain, then go in for supper.

 

I agree with Patrick, a new crush washer, the "gasket" is cheap insurance. A new one will also help with the tendency to over tighten the drain plug. If you don't mind the expense, K&N oil filters have a 1" wrench fitting to facilitate removal. Only tighten by hand. Make sure you lubricate the new filter seal with clean oil. Over tightening can cause the filter gasket to distort which will cause a leak.

 

Sorry to bring up this old thread. But so what is the TRUE torque if one uses Toyota's fiber washer for the drain plug?

Almost everytime I do an oil change on my Lexus ES300, and I forget, the fiber washer squeezes out the side at recommended 33ft lbs. When I do 18 ft lbs it does not squeeze out and does not leak. So what gives?

I am reading 27-30 ft lbs for the 02 Prius. I can see that if it was aluminum washer but for the OEM fiber clad washer I think it is too much.

Has anyone else seen their washer squeeze out at 27-30 ft lbs?



TIA,

Jim

 

Third gen Repair Manual says 27 ft lb, fwiw. I've not notice undue compression. Do the washers you get have extra thick coating?

I don't much like the coated washers, for a couple of reasons. With a Honda I'm changing the oil on, I'd torque to the spec. value, and the next time I came to remove the bolt, it was practically loose. Seemed like the coating was compressing. I mentioned at a Honda parts counter, and they came up with plain aluminum washers, they stock both types.

And with the Prius, the (coated) drain bolt washer always royally glues itself to the oil pan, when you're removing the bolt. I'm used to it now: loosen the bolt a couple of turns, then break the washer loose with a tap from a screwdriver/hammer, then carry on removing the bolt.

 

They are Toyota Factory seal washers. Extra thick? I do not know, I do not have anything else to compare to except my Porsche Aluminum crush washers which require 51 ft lbs at the crank plug and 31 ft lbs at the tank plug.

A long time ago when I had jiffy change the oil, they tightened to spec 33ft lbs (upon my demand, they complained it was way too much) and it leaked out the side.