I replaced my valve cover gaskets and being 2+ months, nothing has changed in terms of oil consumption. I'm going to have to go with that the piston rings are going bad. Will likely do an engine swap in the coming years.

 

Try a couple cans of Yamaha Ring Free. Change oil after 2 tanks/2cans of cleaner have been run through. Freeway runs, and pulling some RPM is best, maybe head for a hills and make it work a little.

Start there before buying new engine.

 

I have a 2006 IS350 and I've did too noticed oil consumption and smell of oil. It turned out being a Leaking Timing Cover which will cost ALOT! I've always used Conventional Oil to prevent the oil consumption but until one day after reading what other IS owners did was to upgrade to synthetic oil and use that Lucas stop leak. I used 1 bottle (quart) to substitute 1 quart of oil for the next 3 oil changes and what did you know? It stopped the fast oil consumption . So I stop using the Lucas stop leak and started using Licas Synthetic oil stabilizer and continued using full synthetic. This was 3 years ago and still doing a great job slowing it down. Took it to Lexus dealership 2 weeks ago and said timing cover is moist not leaking like before

 

Used the Yamaha Ring Free for 2 fillups and it's doing wonders for my fuel economy so it seems to be working, will check up on oil consumption in the near future. I'll check out the front of my engine for the timing cover, thanks for bringing it up

 

So, now I give up.
I did BG engine flush, valve clean with CRC, Rislone engine restore and finally 3 fills with Yamaha ring free.
Now it burns 1L per 1650km. As per manual 1L per 1000is a norm.
Initially I had 1L per 1000km or so.
On a bright side engine runs smother after all that and it burn a bit less oil too. I can live with that.

 

Thanks for the updates, I'm looking to try the BG Flush you recommended as I too am burning about 1 litre every 1,600 KM. Car's currently at about 311,000 km.

Recently, I've had the PCV valve, spark plugs, and transmission fluid all changed but ddin't help with the oil burning. Used a litre of Lucas Oil Stabilizer in my last oil change and it did seem to help the oil burning subside but just by a little, (1L per 1,600KM now, but use to be 1L per 1,300km).

Has anyone ever experienced the pistons or psitons rings truly failing? I absolutely love this car aside from this one issue.

 

So I followed the instructions for BG right to the letter. Oil came out black but it didn't solve my oil burning issue sadly.

 

Any update on your oil consumption with Yamaha Ring Free? I used Liqui Moly Engine flush on my 15 IS350 to help with the oil consumption and see no difference in terms of oil consumption. Car definitely runs much smoother and sure is more jumpy when accelerating.

And for reference 5k oil changes at dealership since 30k (currently at 167k). I am assuming rings are probably worn (years of seeing high RPM has caught up to me LOL) but want to try some additives before reaching to that conclusion.

 

Does anyone here downshift and use the engine to slow down the car? For example when going downhill you shift to a lower gear with the paddle shifters to help slow down the car. I was doing that and my car would burn oil like crazy. I stopped doing that and used the BG engine flush along with Yamaha Ring Free and my oil consumption has gone down quite a bit. Hope this helps someone out.