Ryan300

My 2001 Rx300 started to leak oil near the oil pan area. The leak is not from the lower oil pan but from inside of access panel. It could be coming from the upper crankcase oil pan. It could be the top crankcase seal failed. That's the only place I think oil can leak from judging from the source of the leak. Where else can a leak from this area come from? How difficult is it to reseal the top crankcase oil pan? Is there a write up posted for this job? Any advise or suggestions is appreciated. Thanks



I removed this cover panel where the oil leak is coming from.

No leak in Lower oil pan. Could be the top crankcase oil pan seal.

I can see the top crankcase sealant from this view
along with the lower oil pan sealant.

salimshah

Trick in tracing oil leak is to trace from the top.

Once you zero in on the source, the cost benefit risk analysis needs to be made.

At times placing a cardboard piece underneath and topping and adding a 1/2 quart once a month is OK.

Salim

Androman

Couldn't it also be the rear valve cover?

Ryan300

I could probably live with topping off once a month but the wife will not be too happy with the oil puddle on the driveway and/or garage.

If the leak didn't come from inside the access panel, the rear valve cover can be suspect as source of leak. But I will check it

I know for sure it's not the lower section of oil pan. But besides the top section of crankcase oil pan, is there anywhere else a leak can develop in that area? Can a rear valve cover leak enter that area and exit on the thru the access hole?

Ryan300

There's no trace of oil leak from the oil filter down to bottom section of oil pan. I verified the leak coming from inside the access panel. That's the reason I think the leak is coming from the top section of crankcase oil pan #20 of the attached diagram.

salimshah

There are weep holes for front and rear oil seals.

Typically in RX the leaks happen from valve cover gasket [typically 90K miles] or the two seals.

Toyota/lexus pan gaskets also have a tendency to leak at 200+K miles.

Salim

ukrkoz

If it's leaking clearly out of inside the transmission bell housing, where it junctions with the engine block and oil pan, it's crankshaft seal. I am not aware of any upper and lower C-shaft seals, it's front and rear main seal.
We actually had leaking front main seal on our RX300 at around 40 something thousand miles. They replaced it under warranty.

Ryan300

This RX has 132K miles.

So if the valve cover is not leaking, and the lower section (main) oil pan seal is not leaking, is it safe to say the upper section of crankcase oil pan seal is the culprit? How difficult is it to remove and reseal that section. I've done straight forward oil pan reseal on an Infiniti G20t but not a two piece Lexus crankcase oil pan (upper and lower section).

Ryan300

@ukrkoz #1 shows top section crankcase oil pan seal and #2 shows lower seal. I'm hesitant to tackle this project. I'm not sure what or how to approach it. I need more info and direction before I'm comfortable starting this project.

View of top and bottom crankase oul pan and seals. I'm thinking of resealing both.

ukrkoz

We are talking different seals. You are likely referring to upper and lower gaskets. Seal is round donut inserted into the engine block with crankshaft coming through and out. Gaskets are flat, seals are donuts of various shape and form

https://www.partsgeek.com/gbproducts...ad=47584901292

It leaks into the transmission bell housing, then seeps down and out right at the junction of the two. Yes, it is quite a deal to get to it, to replace a $6 part. As you have to disconnect transfer case, driveshafts, to pop transmission out.

Ryan300

Not what I wanted to hear. I was hoping for a DIY fix but it sounds like I have to live with a leaky car.

Thanks for all the comments. They gave me great insight on how not to DIY.

salimshah

So what is the source of the leak? I was unable to figure this out.

Please have that determined by paying some one [usually they do it for free .. just compensate them for the time].

Then we can put our heads together to suggest what can be done,

Ryan300

I took it to a local repair shop and was told it's the rear seal. It's about a 6-7 hr job plus parts which includes the seal and transmission fluid. I'm looking at approximately $700 to stop the leak. He said looking at source of the leak near the flywheel, it is likely the rear seal.

salimshah

Folks talk highly of additives to help rejuvenate oils seal. I am not a fan of those, but that is just me.
There are heavier weight oils that can reduce the oil leak.

Salim

Ryan300

Thanks for the suggestions. I may try them temporarily until I can save enough money for the expensive rear main seal repair.