I have owned 4 Lexus, 92 SC400, 98GS400, 98GS400, pushing all these cars over 200K miles and now this 07 GS350 with less than 90K miles is using excessively amount of oil. None of the prior models used oil like the 07 does, even the 92 with 270K miles did not use oil like this. Matter of fact none used more than a quart between oil changes which I always used Mobil 1 changing at 6000 miles. I still have a 98 that uses not 1/4 quart between oil changes and it has over 200K miles.
Since I have used the same oil in all the cars, it is not the oil grade, brand or the time between oil changes.
The factory is Bull ****ting us all to think that it is normal. It is a internal engine problem which they will not admit to. The higher HP is not an excuse since oil usage comes through the rings or the valves seals or leaks if you have them, which I doubt you do often. Now I just changed the plugs on the 07 GS350 with 90K miles on the plugs with no sign of leakage in the valve seals, so it has to be in the rings or more importantly in the oil ring itself. The amount of oil usage would show on the threads of the plugs, and they were super clean for being in there for 90K, worn out but clean threads.
If we band together we can force the factory to fix the problem. But it takes everyone to join up and demand that this is fixed and it should be. We pay a premium for these cars and to have the quality go down such as this should not be.
We could circulate a owners petition for a recall and it would get them moving on doing something towards fixing this issue.
How many want to join up and do this?
Thank you for your time.

 

Am I missing something or did you not specify how much oil you ARE using now?

 

1 quart every 1200 to 1500 miles

 

Same here for the past few years. I' had a 07GS350 with 140k. Dealership says its "acceptable". There are multiple threads on here regarding this, its common. I will never buy another V6 Lexus.
Both my cars now are V8s (2015GX and 2012F)

 

Try doing a top engine cleaning, you may have carbon built up clogging the piston rings. Run a few bottles of seafoam through the intake with the engine warmed up.

 

More usage than past Lexus' but it doesn't seem over the top to me. Try a Hi Mileage Synthetic and see if that helps.

 

It is very possible that at the factory the rings are installed incorrectly. This can account for the usage yet not affect the performance, one shift at factory misunderstands the installation instructions and the other shift knows the proper way to install. As I do not think that all 350s use this excessive amount of oil. And yes I realize it is not a big cost right now but can be later on down the road as mileage increase as the build up in the system continues to accumulate over a long period. It is a just a pain that I have to keep checking the oil level and can not rely on it. The oil has to be going somewhere and that is through your exhaust system if it is not the valve seals.
The 350 have a very high compression ratio of 11.5 which would require a high performance set of rings.
The 350 is certainly one heck of a performing engine and impressive for the liter. It could be the quality of the rings as we all know that Lexus quality in some areas is not what it used to be. Maybe they do not want the engines to last like they used to and want us coming back for repairs which is about 70% of Lexus dealers income.

High oil consumption and blow-by can be caused by any one of the following:
A. External leaks
B. Failure of accessories
C. Valve guides
D. Internal leaks
E. Piston ring and cylinder combination
OR if cylinder wall honing is not done correctly in some case.

IMPROPER RING INSTALLATION--Can increase oil consumption many times.
Compression Rings Upside Down - Will tend to scrape oil up into the combustion chamber instead of down into the crankcase. Rings with an inside groove counterbored should be installed with the groove to the top of the piston.
High performance rings are designed to put more oil in the system due to the higher output of power, but not this much.
Bottom line is there is many complains about this and Lexus should own up to it and make the repairs that are necessary for its loyal owners.

 

I would just get rid of the car and buy another one. A later year 350 or 460.

 

Appreciate the input, this is an 07 GS350 AWD which is excellent except for the excessive oil usage, even averages 28 mpg combined hightway and mountain terrain, great in the snow. Maybe the V8s are made at a different production plant.

 

Try changing the PCV valve...it's a long shot but it too can cause oil consumption.

 

Good point, plus it doesnt cost much to replace it.

 

yelp, changed PVC long time ago and actually did help a little

 

Open a few spark plugs out and see if you can borrow a small borescope take a peak inside of the pistons and see whats going on. If theres a lot of carbon then youll need to find a solution. If there clean you might want to look else where.

 

Doing a top engine clean/ walnut blast and adding an oil catch can would also help significantly reduce oil consumption. seafoam would help maintain a fairly clean top end but if you have too much carbon they would just eventually end up clogging up the catalytic converters. which will be another expensive replacement.
-Best thing to do is put the top end cleaning solution ( ac delco top end cleaner ) in thru the spark plug hole, rotate engine by hand to distribute the solution allow to soak for about 30 min vacuum out as much as you can then place a clean rag over the spark plug hole (disable the fuel and ignition by pulling their fuse or relay) and crank the engine over several times with the starter.
This is an updated tsb before replacing the rings and valve stem seals.
I have done this to my 2006 gs300 and went from 1 qt every 500 miles to about 1 qt every 2500 miles, recall was never done so still have the original rings and valve stem seals i'm at 160,000 miles

 

I was about to suggest the same thing except fill the cylinder with seafoam or AC delco place plugs back in and let it sit over night. Will turning the engine over by the crank pulley with a breaker bar. Pull the plugs and using compressed air blow out all the seafoam out of the cylinders. Then changing the oil Im glad that method worked for your GS300