cspencer1

4 months ago I went for my oil change after 3000 mi. My low engine oil light was on. Mechanic said I had no oil in my car. He put in 6qts and told me to take it to the dealer. I did and they had me drive for a 1000 mi and bring back. This went on for 4 months and 4000 mi before they said they had diagnosed the problem. They said that I did not have a consumption problem. They said I had a bad engine oil sensor. I work everyday so I decided I would get a new sensor on a holiday off. a couple weeks after that I checked my oil a lo and behold there was no oil in my car. Has anyone experienced this problem

bayer

The stealership won,t admit to it,but a very common problem with these engines.They consider 1 litre per 1600 kms normal.It seems to start after 100000 kms.I wonder if they would like to pay the price of a Lexus and have to add oil often.

TimNBD

I have to add 2 quarts of oil every 420 miles. It was 2 quarts every 800 miles when I bought thew car 3 years ago @119K miles. Now I am at 170K, its been getting worse. The fix is to replace the piston rings with the redesigned set, and the labor cost to do this is huge. New piston rings are about $750 in parts, $3000 in labor.

This is the first and last Lexus I ever buy.

bayer

On my last oil change I used 5-30 Mobil 1 and over 4000 kms later dipstick shows down half way and has been there for about a month.

LX470Mack

Is this problem on the 3.0's too? Or is it just the 3.5? Not good to hear.

bayer

Read previous threads on oil consumption.Common in 300 and 350

pbxcomm

Hey all..
I've had the same oil cumsumption issue back @ 100,000 mi.. I discovered I needed to change the oil at a more frequent interval. So I switched up to every 1000 miles.. Each time I change the oil (three oil changes/3000 miles), the filter appeared that it had 5000 miles on it. I really believe these engines burn "dirtier" than most, so I beleive the changing intervals need some re-thinking. Anyway, the last oil change was nearly 4000 miles ago and not one drop of oil has been consumed. By the way, I always use Royal Purple 10w-30, I will never run 20w oil in my GS, its equivalent to hydrolic fluid and I think that is where it belongs.

Regards

Sodium

Have you ever replaced the PCV valve?

EDIT: Also, 2 quarts every 800 miles when you bought it at 119,000 miles? Sounds like something caused by sloppy maintenance by the previous owner rather than a manufacturing defect

ibidu1

iTrader: (1)

1: Search for obvious leaks, if none
2: replace the pvc and do induction cleaning
3: if theres still oil lose do a compression test to see if the piston rings are worn out

Personal I dont like to run synthetic oil, only regular catrol gtx. Im at 160K miles with no oil lose issues.

TimNBD

I replaced the pcv at 142K mileage and it made no difference. there are no leaks. I have even checked the torque converter housing to see if I am losing oil past the rear main seal. It has been confirmed through a leak down test that the pistons are leaking. My mistake was not doing the leak down test prior to purchase, but it was cold winter at the time.

There is a reason why Lexus redesigned the piston rings for this engine around 2010 - they wouldn't do it just for the hell of it, they will do it to make their warranty numbers look better for this engine.

ibidu1

iTrader: (1)

In your leak down test which cylinder had the most leaking? Have you tried looking inside the spark plug holes to see if theres carbon built up on the rings, or maybe even tried a borescope to see whats actually going on,

If its carbon issue clogging your rings, you might be able to pour a little bit of ATF fluid mixed with berryman into the plug hole making sure to saturate the tops of the pistons and letting that sit overnight. Then next day using compressed air blowing out as much fluids as possible and see if that helps

Sodium

And you know this is the reason because you were one of the engineers involved in the redesign, or one of the executives who approved the redesign?

And going back to your oil consumption for a moment – burning two quarts every 800 miles, and especially two every 420 miles, is a far higher consumption rate than most people here have reported, so you can't reasonably blame it all on defective piston rings. The fact that it was already burning two quarts every 800 miles strongly suggests that the previous owner did a terrible job maintaining the car. It does suck that you bought an oil burner, but no point in trying to place blame based entirely on conjecture! Definitely try ibidu's suggestion, ATF + acetone is great at cleaning carbon deposits. Turning the engine with a breaker bar while the pistons are being soaked can also help to loosen them up

Also, lets not forget that a lot of issues like this result from car companies trying to eke out a few more tenths of an MPG to comply with the plethora of regulatory impositions that governments continue to burden them with

TimNBD

As a former GM and Honda engineer working in the auto industry for many years, any time you see a redesign, it is based on warranty data over about 2-3 years. Transmission and engine related issues may drive a re-design sooner.

Let's just say the calibration didn't go as well as they thought it would...

I have done the sea foam treatment twice in 3 years of ownership. That improved the acceleration and fuel economy numbers, but did not resolve the oil consumption issue. The vehicle will be disposed of shortly, for a direct injection STS.

iGS430

See what had happened was, Lexus engineers decided to try a different piston ring design in the GS350 models, which was a disaster, a TSB came out to have the rings replaced by Lexus at no cost between 2009-2011, at the current time Lexus isn't honoring that TSB anymore. Save up for a piston ring job if you really love your GS and want it keep it for another 300k miles

ibidu1

iTrader: (1)

From 2006 GS300 all the way to 2016 Lexus GS350, GS450H, and IS350 RC350 etc. These cars do not have a fault in the design, only not properly maintained engines will suffer.

I run regular castrol gtx 10/20 oil every 2500 miles I have nearly 160k miles no issues with burning oil or oil consumption. If you run old plugs, dont do top engine cleaning (seafoam/bg etc) this will allow carbon to build up between the oil rings and the piston.