Good day gents,

So my 2013 Rx350 F sport with 77k started leaving oil spots overnight.

Since ownership underneath the Rx has been oil free. Recently, my oil was changed at the Lexus dealership in November, and the alternator went out on me three weeks ago and was changed by an independent mechanic. I started noticing the oil droppings four days ago.

I can’t locate the leak from the top of engine bay.

From doing some research over the pass couple of days, the leak could be the rear main seal, or the timing chain cover.


With no warranty it looks this is a $3k plus repair.
In some instance some owners have had recurring leaks after having the dropped and the seal replaced.

How have some of you guys who have experienced this handle it?

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The infamous timing cover leak is rarely anything more than a small seepage, not enough to even affect the oil level on the dipstick. Most owners do not spend the insane amount of money required to fix it.

You need to find the source of the leak in order to determine what to do.

 

Clean it off with some spray brake cleaner (when the motor is cool) and watch to see where it starts leaking again, or if it does leak. I would also get a wrench and check all of those bolts for looseness. Others have found loose bolts on the timing cover.

To see the timing cover leak you have to remove the passenger side front tire, get a flashlight and look through the wheel well at the left front side of the engine timing cover. But your photo is of a different area of the engine, it looks like the side near the exhaust manifold down pipe.

 

Your pic is at the cover plate for the torque converter to flywheel access bolts, which is in the RMS area, but as suggested above, do not assume it came from there. Oil fles around a lot and seems to accumulate in that location. My 2GR-FE had same oil residue there, and since I had the engine out anyway, I replaced the RMS, but it was bone dry, that residue must have come from some other place in my case. Even a sloppy filter change can do it...

 

Guys, thank you very much for replying with your insights. It's much appreciated.

Seeing oil under the Rx for the first time has been troubling. I plan to dive into the diagnosing the issue this weekend using some of the methods mentioned here.

Mesquite77, What is the RMS?

 

RMS = Rear Main Seal (of the engine) it is between the engine and transmission.
It could easily be from spilled oil or even a leaking oil filter housing or valve cover gasket (an easier fix).

 

Clutchless, thank you!

 

For the RMS, what is the process or bolts that I have to remove to verify if it's an actual leak or just shoddy workmanship on the oil change?

 

Don't remove anything. Do look under and around the engine with a flashlight, remove the plastic engine cover (the big silver one - it just pulls off) and look around. For the oil filter lay under the front bumper and look up. You may have to move or push some plastic under shield around.

Just clean it off and watch for more leaking. I recommend spray brake cleaner. It dissolves every kind of greasy oily grime so it dissolves and drips away under the car, then it evaporates in minutes. So spray it in somebody else's parking lot or street or put some newspaper under the car. Brake cleaner is flammable so do it when the engine is cold or barely warm. Every auto parts store has it or even Wal-mart.

 

If you are very determined to locate source, remove belly plan, and clean everything, leave it off while you drive a bit and check later.

 

Thank you both. I will give it a go tomorrow.

 

FYI the belly pan has a lot of 10mm bolts and plastic anchors that can be pried out. It is a lot easier if you can attach a 10mm socket to a small cordless drill driver.
On the plastic anchors use a tiny screwdriver or trim removal tool to try and pop our the center part first which unlocks it before prying it out from the outer edge. They do tend to break but you can find them on eBay or Amazon.

 

Hello Gents,

Over the weekend, I was able to get under the vehicle and further diagnose the source of the leak with help from a friend.
The leak is indeed coming from the rear main. The funny thing is the amount of oil that's dripping down overnight onto the cardboard cut-out that I placed under the vehicle has reduced. My drive miles are still the same. The oil level on the dipstick remains the same. I will continue to monitor the dipstick.

 

That's bad news. You can buy a lot of oil for what it would cost to replace the RMS. If you do, be very careful to put some grease on the spring of the seal before tapping it in, it can jump off and end up in the crankcase otherwise, and you'll never know it, the new seal will just leak. If you go that route, I would R&R and reseal the RMS retaining plate/holder, which avoids spring jumping off problem as well since you can mount the seal in it outside of the engine.

Retaner:

 

BTW, note that the seal holding plate is also sealed with RTV around the perimeter, and that may be source of a leak instead of, or in addition to the RMS.