Your mechanic found no leaks and if there were, you would see the evidence on your driveway. Or simply look under the car.
I would pull the spark plugs and check their condition. Your engine's plugs last a long time and should look clean even after many miles.
My guess is you will find some oil fouled spark plugs.

Good luck!

 

@smithfh - If your engine is burning that much oil, it’s probably an engine that is wearing out. It's as simple as that.

Over time, the piston rings have likely become worn or stuck in their grooves, preventing them from sealing tightly against the cylinder wall.

The tiny gap that has formed between the ring and cylinder wall allows oil to enter the combustion chamber and burn. Worn valve seals produce the same effect.

Most stock automotive pistons contain three rings. The top and second rings are responsible for pressing tightly against the cylinder wall and sealing the combustion chamber, keeping combustion gases in and oil out. The oil ring scrapes oil off the cylinder wall on the way down the cylinder, depositing it back into the oil sump.

Bad valve seals can cause a car to burn oil. Valve seals also help prevent oil from entering the combustion chamber.

Because oil is present to lubricate the seals and keep them pliable, some oil will naturally burn during combustion, leading to some engine oil consumption even in a fairly new and healthy engine, but you shouldn’t need to add much – if any – top-off oil between oil changes.

Engines with many miles are going to use more oil. Blame it on friction. Despite best efforts, things eventually wear out, including engines. Worn rings can allow a gap to form between the ring face and cylinder wall. During operation, oil can slip past the rings into the combustion chamber, where it burns. Worn valve seals also contribute to oil consumption. Stuck rings as a result of heavy deposits can result in the same scenario.

Like us humans, you can't turn back the hands of time and you can't undo the number of times an engine has rotated around-and-around or lower the mileage an engine has logged.

So, how many times has this engine rotated in 175,000 miles of driving?

For simplicity I'm going to use 80mph as the speed for calculation. Also I'm just going to say the engine started fresh off the factory floor and didn't stop because I don't really want to take the time to take idle into the calculations.

So traveling 100,000 miles @ 80mph = 1,250 hours. But if the average speed is reduced to a more logical 40mph, traveling 100,000 miles would take 2,500 hours! So, my calculation of engine revs based on just 1,250 hours will probably be way too mild so I will need to adjust for that as you'll see.

I'm going to say that the engine averaged revving at 2,000rpm. So if you take 2,000rpm x 60 minutes = 120,000rph (revs per hour). Then you can take 120,000rph x 1,250hrs = 150,000,000 engine revolutions in 100,000 miles. That's around (excuse the pun) 262,500,00 engine revolutions in 175,000 miles traveling at 80mph.

But wait! Traveling 175,000 miles averaging a more common 40mph (instead of 80mph) is 525,000,000 or ½ Billion engine revolutions! Oh my Lordy!

A half a billion revolutions of a heavy rotating mass of metal with pistons being forced up and down inside cylinders and valve stems sliding up and down against its guides is going to produce a significant amount of wear that no lubricant can prevent from happening. Lubricant can only help reduce wear, but over-time wear is inevitable - it cannot be avoided...


My best guess, and it's only a guess mind you, @smithfh has an engine that is showing signs of being worn out! That is why his engine is using about a quart of oil every 1,500 miles. Makes perfect sense to me!

But at 175,000 miles this car apparently is still very much a dependable and nice driving car. Chances are pretty good it'll still be going at 250,000 miles...and maybe much more.

My recommendation is to keep an eye on the oil level and change the oil and filter as recommended by Lexus. If/when the oil level shows a quart low, just add a quart and drive on..

 

I wonder if they pulled the covers off the lower engine? There's a lot of places for oil to drop and not hit the ground for quite a while.

I still think you need to pull the plugs to see if they are all oil fouled (indication of neglect) or a single cylinder (indication of part failure) is oily.

 

@smithfh - I'm curious to know, has your 2014 GS 350 always had the recommended servicing done since it was new, and has the service always been performed by a Lexus dealer or some other service center? Was any service Lexus recommended doing skipped-over and not done; like brake fluid flush, coolant change or replacing spark plugs?

As you probably know Lexus/Toyota does not recommend ever changing the 'lifetime' automatic transmission fluid. I'm curious to know if your transmission fluid has ever been changed and if so, why. And, I'm interested to know how your transmission is performing now that it has been driven 175k miles.

 

I have the same problem right now with my 15 IS350. I am also at similar miles (172,000) and done oil changes every 5k since ownership (30k). Been RR tuned since 60k and FBO since 100k. First time I noticed the low oil engine warning light when I was driving hard and at the time was over 1000 miles of my 5k OCI. This was at 165k. I never smelt any burning oil/ saw any leaks ever ( catless exhaust) and only burned during high RPM/ under heavy load. Was burning 1-2 quarts every 5k and potentially more under spirited driving.

Did a Liqui Moly Engine Flush and it did clean out some gunk in there as my oil isn't as dirty now at 5k OCI. But now I smell burning oil from the exhaust after normal driving coming to a light or under light acceleration. After the flush, I started leaking oil from the infamous "Banjo bolt" on the oil line and resolved that. No more leaks, burning oil smell. Car runs better but I still burn the same amount of oil.

At this point, car has been driven a hard 140k miles since I owned it. Oil is obviously burning in combustion chamber probably from worn piston rings or valve stems, or scored cylinder wall. When it is warmer here in Boston, I am going to pull the plugs and check the cylinder walls for any scoring, compression test. I know power drops off at higher RPM. Likely, motor is starting to show signs that it has had enough and overtime will continue to burn more oil as more miles get driven.

I do enjoy this car, especially the exhaust. Likely, will buy a used 2GR-FSE engine with low miles and enjoy it for another 150,000 miles. 2GR-FSE has proven its worth.

 

Sorry to hear this. A few things I wonder about in this case? Were there 10k oil changes before you got it at 30k, if you know? BTW: The Air Filter is the best Oil Filter. The Lexus brand Factory oil filter is best used for many reasons. What oil filters were used?

You have the RR Tune pulling a 7200 rmp shift redline correct? I know that that tune will sometimes not shift and pull 7400 - 7500 shifts. My friend has it and he had to get off the pedal as it was climbing past 7500rpm's one day and did not shift yet still.

Did you just keep the looks ok spark plugs in there or changed them at some point? They should have been changed almost 3 times now. Fuel type always Prem, to help with a complete burn in the combustion chamber reducing carbon and unburned fuel build up?

The Oil burning is likely also 100% in the cylinders with the rings in the combustion chamber. For some reason many here just don't think oil burning is possible , but it is for real. Excessive oil burning has been going on with this motor is some cars depending on maintenance from the 3rd Gen GS, 2nd Gen IS, RX350 and ES350 V6. This is also happening to other IS350's in the CL IS forums also.

What Bolt on's do you exactly have? Headers? Intake type? Exactly what are all the FBO mods?

 

I assumed they were 10k OCI for the first 30k. Once I purchased the car, every oil change has been at Lexus since 30k till 160k. So OEM filter and Lexus 0W-20. Since the low oil warning light came on, I started using better oil to see if it makes a difference (used Mobil 1 EP and now Pennzoil Ultra Platinum) but unfortunately it does not. Maybe different outcome If used better oil when I bought my car? Who knows.

Yes I have the RR Tune and shift point set to 7200. Where people have the "shifting" issue - only happens in auto mode and for me in the rare case where I let this happen it just banged off 7200 and then shifted. I typically drove in manual mode so for me this wasn't an issue revving it to 7200. Never saw it go past 7200. With the tune, I have PPE headers and Ark catback exhaust and stock air filter. Crispy downshifts on the regular used to me music to my ears haha but no longer the case as I drive easy now to preserve the life of the motor.

I have done spark plugs 2x and both times were fine. Some darker than others. Fuel was always 93 Shell or Mobil. Even on long trips would go out of my way to find them.

Do I think I would be burning oil if I did anything different? Personally, yes. Wish I used better oil to match my driving style and did shorter OCI - 4k? This is the only issue I have had with the engine itself and happened to be when I was on "old" oil (6000 miles is over for my 5k OCI) and driving WOT all the time. I have done all the maintenance and taken good care of the the vehicle. Rarely beaten on when cold in my ownership unless I needed to change lanes, always warmed up before driving. All Fluids changed, etc.

There are people out there driving the 3IS 2GR-FSE with 220,000 miles + and not burning a single drop of oil. These motors are quite reliable even in higher miles if taken care of. OCI are what kill toyota engines.

 

First of all again I am sorry you had this problem. I think you are right about Lexus 10k oil changes at 1st. No matter how good the oil looks or whatever else, that is too long. Especially the 1st oil change when you have internal break in particles. Oil is subject to contamination. Those contamination can wreck piston walls and rings. I personally only use Pennzoil Plat in all my cars only with OEM Factory filter only. As a example we had a 15 Kia Optima SXL Turbo 2.0 GDI. While all the Kia motors were blowing up, with 5k oil changes we sold it at 148k and had zero problems.

I run Headers, Intake and D3 Performance Tune, custom mid exhaust with Tanabe Catback, also Port upper/lower intake Manifold and Enlarged TB. It's set to 6800rpm shifts and redline. With everything else that 7200rpm Tune could have aided in the problems also IMO. There was a guy FB who just made 400k on his 2GR-FSE GS350 2013. He mentioned he did 4k - 5k oil changes. There is also good need to do periodic Intake combustion carbon cleaning and in tank cleaners. Carbon can kill the 2GR due to the design of very tight tolerances. Thanks for sharing. Hopefully some here will stop thinking no need to do this and that.

If and when you decide to replace the engine there are some good ones to be source at great deals on Car-parts.com


Just a few of many I have seen over the years.
https://www.clublexus.com/forums/is-...uestion-2.html

https://www.clublexus.com/forums/gs-...ce-engine.html

https://www.clublexus.com/forums/is-...d-smoking.html

 

You said; OCI are what kill toyota engines.

What do you think the OCI was for those 2GR-FSE engines with 220,000+ miles and not burning a single drop of oil?

What weight oil do you think was used in those 2GR-FSE engines with 220,000+ miles and not burning a single drop of oil?

 

Definitely not 10,000 mile OCI and 0W-20. I haven't tried it and probably wont, but some CL members run 5w-30 in their IS350 to help with oil consumption. There is one member on FB Lexus group, 270k miles on his 14 IS350 regular oil changes at 5k and no oil burning.

I have a 2009 camry 4cyl as well and doesn't burn any oil because 3k oil changes since new. 2007-11 camrys are notorious for oil consumption.

 

I cannot imagine keeping a regular ol' car that was mass-produced and nothing unique or special for 270k miles. The unavoidable interior wear, the sandblasted windshield glass, the worn-out suspension, the old technology, and so-on and so-forth would drive me absolutely bonkers . I'd be really tired of looking at the same old car I had nestled my butt down in many thousands of times. I guess some people enjoy driving cars well past their reasonable lifetimes and don't get tired of old worn-out stuff. Count me out because I'm not the least bit interested!

You may want to dig into some research about 0W-20 and even 0W-16 engine oil recommended for use in modern engines to learn about how it fulfills all facets of lubrication and does an excellent job to reduce wear over the engine's life, whereas the higher viscosity oil grades you mentioned proved to fail at doing the same.

Changing engine oil and oil filter at 3k miles with the synthetic engine oils we have nowadays is just as ridiculous as throwing out unopened factory-sealed food just days after buying it even though its expiration date is months or even years in the future. If doing that satisfies your conviction, then by all means have at it! I've also heard of people setting an alarm clock to remind them four times a day to take a bath or shower every six hours - strange habit but I guess doing that satisfies them too.

Maybe you like for your lawn grass to be mowed one time before its actually mowed for real...and then go through the same process the very next time!

 

Thats a great opinion. It's just as mind blowing to me that people like you lease cars and drive 4000 miles a year then have the nerve come to the forum and comment nonsense things.

 

Thank you! My opinion was indeed great - borderline brilliant compared to the hogwash you're spewing. The mental gymnastics needed to be you must be exhausting!

Perhaps to state the obvious, your 15 year-old 2009 camry 4cyl with 3k mile oil changes is not worth one penny more, nor will it last any longer, than if you had only done half the number of oil changes by following Toyota's recommended oil change schedule. But now that you've overdone the oil changes and worn out the threads on the drain plug what are you going do with the old decrepit 4-banger you took such loving care of?


Speaking of leasing, maybe you can tell me how people on the dole buy or lease their vehicles.

 

Hogwash? Didn't know you are still living in the 1800s. Probably saving your wife for the next guy?

You must be isolated from society in your 300 sq ft apartment behind your keyboard looking to comment on the forums to make yourself believe you are adding "value " to the world.

Back to the original topic of this thread, you have nothing to add here in terms of burning oil since you don't drive your car. Can go back to doing your Crosswords in the newspaper.

 

Knock off the rude and personal comments or do not post here please