Prius Gen III 96K miles indicated 'oil pressure low' 2K after last oil change. Fortunately we were only a mile from home and were able to drive it home on battery charge. We exclusively use synthetic Mobil 1 0W-20 oil. The oil pan bolt was dry, and it appears the leak is coming from somewhere above the oil filter canister, which I verified being seated and tight. After the engine cooled, I drained the remaining oil (about 3/4 quart) and removed the oil filter canister to check the O-ring seating and integrity of the filter. All appeared normal. After reinstalling drain plug and filter, I slowly put in 3 quarts oil to minimum oil level indication on dipstick. Started engine and ran it for 1 minute and checked for leaks -- no leaks. Turned off engine and allowed the car to sit overnight. The oil level remained unchanged the next morning. I started engine and let it run for two minutes this time, at which time it started leaking rapidly (fortunately I kept the oil catch pan underneath the car). So the oil leaks when the oil pressure rises with warming engine. Any ideas on what I should check to determine the cause?
If you are positive that the oil filter is seated properly and tightened, you'll have to go to Toyota to get a proper diagnostic. It sounds a bit weird from your description of it leaking rapidly after running for 2 minutes during warm up. If this occurred everytime during startup for 2000 miles, you should have gotten a low oil warning a looooong time ago.
As you stated the leak is somewhere above the oil filter canister, get yourself a good light, inspection mirror, box of towels and some alcohol. Clean and isolate.
Agreed. You stated that it started leaking after the engine warmed up, but did not mention specifically where the leak was coming from. Please give us an update...
For what it's worth the oil pressure is probably highest when firs tstarted cold. As others have suggested, you need to see where the leak is.
