When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 2007 GS350 with 73,000 miles. I noticed about 5,000 miles ago (when I started driving mostly freeways averaging 60MPH) that I'm losing 1 quart every 1,200 miles. I have no leaks, nothing smoking and the engine bay smells fine. It's a 12 year old car, 6,000 miles/yr driven and I like it a lot. Not looking for an excuse to buy another car.
Do I just refill a quart every 1,200 miles until my usual 3,500-4000 miles oil change, start using a thicker oil from the next LOF moving forward, or add an additive that might decrease oil loss? Car runs fine otherwise. Thanks for the advice.
I def wouldnt go thicker, the reason your car burns oil is more likely from using cheap oil or not replacing it on time. Our pistons have a lower oil control rings, and those get gummed up if you dont do regular oil changes.
I would change the brand of oil that you regularly use, and add full bottle of marvel mystery oil, to help clean and loose up that control ring. Also it would help on occasions if you drive on the highway, punch the gas hard once or twice that will help loosen it.
Per manual, page 381, it's normal to lose about 1qt per 600 miles.
I wouldn't interpret that oil use description in the manual as "it's normal" because many of us do not experience anywhere near that much oil consumption. I believe the correct way to interpret that description is "it's acceptable" as in, Lexus does not consider that excessive and won't do anything to correct it.
I’m curious to know if adding fuel additives like MMO to crankcase is worth the risk. I’ve heard deposits get washed off and clogged in other tiny hole passages.
I have a 2007 GS350 with 73,000 miles. I noticed about 5,000 miles ago (when I started driving mostly freeways averaging 60MPH) that I'm losing 1 quart every 1,200 miles. I have no leaks, nothing smoking and the engine bay smells fine. It's a 12 year old car, 6,000 miles/yr driven and I like it a lot. Not looking for an excuse to buy another car.
Do I just refill a quart every 1,200 miles until my usual 3,500-4000 miles oil change, start using a thicker oil from the next LOF moving forward, or add an additive that might decrease oil loss? Car runs fine otherwise. Thanks for the advice.
After 1,310 miles since the last LOF, I dropped the car off to the dealer to perform an "oil consumption analysis" test (free service). Whatever the results are (and I am open-minded), I'm sure the suggestion will be...It will cost $3,500 to repair (1/2 the value of the car). As for reading in another thread the piston o-rings were part of a recall for 2007-2009 modes, they were not.
Suspects - crankcase ventilation valve (PCV) stuck open, valve stem seals (maybe it smokes a bit during cold start?), piston rings or oil return holes caked, lots of blowby gasses leading to lots of crankcase vent... that's off the top of my head.
Don't panic. Tell us what oil you're using, oil change intervals, driving conditions (city/open road, short or long trips) - basically does the coolant temperature needle reach 90deg (halfway through) and stay there for awhile, do you give it a lot of throttle before it's warm, etc.
Hope you like reading https://www.bobistheoilguy.com/ - read the frontpage ("A review of mineral and synthetic oils"), also read "Esters in Synthetic Lubricants" and " Motor Oil 101". https://forums.nasioc.com/forums/sho....php?t=2714154 - VERY good oil introduction. Subaru's engines (especially of the 2.5l turbocharged variety) are very sensitive to the oil being used. https://www.oil-club.ru/ - use google translate, they have some very good oil analysis over there. Basically, more data to guess base oil formation.
Now, there are many things that you can do, probably none of them will work overnight:
-Fuel system cleaner (yes, you read that right) - read up on PEA-based cleaners (archoil, amsoil, redline, bg44k, techron... some versions of it at any rate, more). Doubt it'll do much for this problem.
-Shorten oil change intervals (OCIs). The oil can't clean forever. The more things to clean (sludge, fuel dillution, deposits, etc) - the faster the cleaning agents get depleted & the faster the oil gets saturated with contaminants.
-Do long drives. Engine oil takes longer to warm up than coolant, and most antiwear/cleaning/whatever additives in the oil don't work (well, or at all, or sometimes they are actually detrimental) when cold. No oil temperature sensor stock on the 2gr-fse, unfortunately.
-Use oils with better cleaning ability and with less residue creation.Off the top of my head, look for:
Low NOACK (sub-8%) results - you want oils that stand up to high temperatures. You don't want more sludge to form where oil can't flow fast enough due to existing deposits.
HTHS & viscosity results (VI (viscosity index) & cst at 40 and 100 degrees) from used oil analysis that closely match virgin oil analysis results (this usually means no viscosity improvers and good quality base stocks - VIs (viscosity improvers in this case ) tend to break up first and start forming sludge/carbon deposits/$#17 like that.
Lots of detergents in the additive package.
Reputation for cleaning engines. Off the top of my head - Shell's high-end oils, Amsoil's signature series, anything with lots of esters. Archoil's ar9100 additive has esters in it, amongst other things.
-Do oil flushes. Detergent-based (Lube1, Archoil, Amsoil, Redline, BG, Miller's I think, ehh... LiquiMoly's expensive one... just read up on it and make sure it's not solvent based). Problems - more immediate action than short OCIs, so might block some oil pathways with gunk... theoretically. I use it in my cars, but they hardly burn oil (well, the 3zz-fe corolla - the gs450h won't even lick.. or maybe it's fuel/water dillution), and run amsoil/redline... so it's slightly (well, very) overkill. Short OCIs with good oils should do the same job in the long run, I think.
-Do piston soaks. Thinks like Seafoam, amsoil power foam through the vacuum lines, stall, take out spark plugs, soak the holes, etc etc... read up on it. Whatever product or method you use, CHANGE THE OIL AFTERWARDS. This is very extreme, but if the piston rings/return holes are too far gone (as in, caked), any kind of oil might not help much.
A bit of warning - ANY of the above might result in the engine developing leaks - basically if it has deposits that have formed around seals, should eventually eat them away. At that point, the seal swellers (esters primarily, I think) may, or may not swell the seals enough to stop the leak. Your call.
I'd start with the less extreme options first. Change the PCV valve, maybe install an oil catch can (good one - baffle and all that) to see if a lot of oil gets lost through blowby, clean intake manifold and MAF, run a few cans of fuel system cleaners through it, change oil to a.. well, you know the type I described above.
Originally Posted by potatomon
Lol, sucker, time to overhaul the engine.
What happened? I thought the 350 was indestructible.
You can just pack some grease into your engine or put some vegetable oil in there.
Going with thicker oil to try and cure oil consumption is sorcery.
Why don't he start by renting a compression tester from AutoZone and we go from there? If the compression is good it will cost like 300-500 for parts and like 10-15 hours of labor to make the engine good again
And yeah def check the pcv and try a quality oil before doing major work but I wouldn't try to degunk it without disassembly, too much risk of ruining the engine then again it could work but not as effectively as taking it apart
Don't even need to check out compression it's good I'm trying Elling you. 73k miles is nothing for that engine you just never drove it properly and now it's developed carbon deposits and the valve stem seals are old. Change rings and seals and this engine is good to go for another 10 years
Probably be fine just cleaning the rings even. At 73k miles they still goos
I'd start with the less extreme options first. Change the PCV valve, maybe install an oil catch can (good one - baffle and all that) to see if a lot of oil gets lost through blowby, clean intake manifold and MAF, run a few cans of fuel system cleaners through it, change oil to a.. well, you know the type I described above.
Do this first! You need locktite red to install it. It cost $8 btw.
03-21-19, 06:17 PM
2007 GS350 - Go with thicker oil
) tend to break up first and start forming sludge/carbon deposits/$#17 like that.