Hello again; I was on these boards quite a bit back maybe 3 years ago, but nothing in the past couple of years.

We have a 2010 RX450h, great car and the only maintenance has been oil changes and wiper blades. Bought the car in 2016 at 60K miles and it's now at nearly 120K miles, so time to think about plugs and a few other things.

The reason for commenting is that last week I did my usual annual oil change but made the mistake of going about 1 1/2 quarts over full (very hard to see new 0-20 synthetic oil on the dipstick and I wasn't thinking). Drove it that way for 5 miles, then went back under the car and drained the excess. Two days later we went for Sunday Brunch and several times I got a panel chime and a very brief message "Low Oil Pressure." Came back home and backed the car into the carport so I could take a look underneath with wheel ramps. Amazed to see a solid black line on the asphalt driveway leading to the car--a serious oil leak. Looked underneath and there was oil dripping everywhere near the front of the chassis.

I wracked my brain, wondering how I could have screwed up a basic oil change so badly. Next day, car was towed to a nearby independent garage that did major work on Toyotas. I then saw on YouTube that one way to have a catastrophic oil loss was via a leak in the oil cooler lines, which were rubber in many of the 3.5L V6 engines back then. The mechanics confirmed my guess and replaced the rubber lines with the accordion metal lines.

Some questions:
(1) How could no one have spotted this major weakness beforehand? Car was bought from a Lexus dealer back in 2016 but surely it would or should have been flagged as needing the steel line replacement ASAP even back then.
(2) Any engine damage? It sounds perfectly normal at this point. When I got the "ding" on the dashboard the Low Pressure text immediately disappeared. I would have to assume that a continuous low pressure would show the message continuously. So hopefully I dodged a bullet.
(3) Could the rubber line failure be related to the oil overfill? From what I've read, if the crank counterweights froth the oil then that could lead to a lack of proper pressure and lubrication. If the crankcase was full of frothed oil, could that oil have simply blown out of some breather and caused the massive oil coating? I never saw the removed rubber oil lines to verify the source of the leak, but the mechanic claimed he added oil and verified the hose failure, so I guess I'd have to take his word for it. And I don't think modern engines have a "breather" tube any more, but instead route the gases to the intake manifold via the PCV valve.

How on earth could Toyota/Lexus engineers design an engine that used rubber lines to route hot oil under pressure, where failure meant a trashed engine? Did they expect the rubber to last forever?

So I think I was lucky to catch this when I did. We'll see...

 

Can make guesses if too much oil caused the line to fail, doesn't help you either way. That line is a ticking time bomb and should have never been rubber in the 1st place, bad Toyota bad. 2GR does not tolerate low oil well at all but if you had some oil pressure the engine will be fine.

For some bizarre reason only select Toyota and Lexus models were recalled to have this line replaced.

 

just was made aware myself from the thread below, but i don't own this engine to have been made more aware sooner. glad you caught it early!

link mentions the rubber to metal line conversion but is not the main culprit of the oil leak.
https://www.clublexus.com/forums/car...-v6-2gr-o.html

 

The rubber oil lines were the subject of recalls and TSBs some years ago. Here in Canada there was an outright recall on them, I had mine replaced long time ago without cost. In the US, I believe there was only a TSB, but I know many folk on these boards elected to have them changed on their own dime rather than wait for the inevitable failure. The additional oil might have minorly contributed to the failure, but only in terms of timing as it was bound to happen eventually. I've seen several posts over the years about people popping the rubber lines.

I'm not sure what the current status of the TSB is in the US, and whether or not there might be some compensation potentially still available. Might be worth having a look...

 

It’s been known for 10 years. Most preventatively replace those hoses and an non issue on 2011 July + manufacturing years.

 

@703 so vehicles built after July 2011 shouldn't have the rubber oil line? I only ask for clarification because some sources I see 2010-2011 model years effected and others I see the full range of 2010-2015 model years effected.

 

That’s correct.