In the case of this leak, we completely power washed the under side of the engine in this area. The car was losing 2 qts every tank on the average and the entire bottom on the right was coated with oil.
Possible cause the PCV valve?
Bottom line the Number 1 or top oil pan can be removed on an AWD RX300 with a little effort and normal hand tools.
My camera was being used as a flash light... It was a drizzly evening and including a parts run and a broken alternator tension bolt.. it took 6 hrs to get everything back together except the alternator. All work was done with the car up on ramps in the front. I've been working on cars for many years, but the conditions and equipment available or this driveway repair were minimal at best. Done on a lift with air tools the time could probably be cut in half.
Sequence as follows:
Disconnect Battery
Drain oil
Remove flex connector exhaust pipe
Remove metal oil pan
Remove Oil pickup tube
Remove all the Number 1 oil pan bolts (12mm heads)
- There is a small 10mm bolt under in the middle at the crank pulley end
- There are two 14mm headed bolts that go into the transmission
- The small cover at the bell housing needs to be removed - there are two more 10mm bolts behind it
- The bolt right above the exhaust pipe is a pain and will not come fully out so remember it is in there as you remove the pan
Remove and aside the alternator
Remove small bracket that connects the AC pump to the Alternator bracket (one nut and one bolt)
Remove the four 12mm bolts that hold the AC pump to the bracket (the bottom 2 thread into the Number 1 oil pan
Remove the 2 bolts from the AC bracket behind the AC pump at the top and pull the bracket away from the engine towards the front
At this point the upper oil pan can be removed. Bring the crankshaft end down and use a pry bar between the frame and the pan to slowly work it down.
Clean everything, make sure the oil pickup tube screen is clean.
I put a black silicon oil resistant gasket maker compound on both surfaces before putting the number 1 oil pan back up in.
Make sure you reinsert the bolt by the exhaust pipe before you put the Number 1 pan back up...
Insert and start all 4 of the AC pump bolts before tightening the top 2 bracket bolts in order to make sure the bracket is aligned with the oil pan.
Pretty much reverse of removal except for installing the AC pump after the Number 1 pan is already bolted in.
I also replaced the PCV valve just in case that was the culprit. If the engine has excessive blow by.
Count on replacing the exhaust gaskets, Serpentine belt and oil filter in addition to the metal oil pan gasket and oil for a oil change.