I'm going to add my speculation that adding MoS2 may actually strengthen the steel meshed headgaskets used by Toyota and prolong it's lifespan. I won't be changing my headgasket until the oil data show it's time to change (if ever). AI response to moly used to coat steel in general: "Applying a molybdenum (moly) coating to steel, or alloying steel with molybdenum, significantly improves its heat resistance, high-temperature strength, and creep resistance. Molybdenum acts as a "workhorse" element that allows steel to retain its structural integrity and hardness at high temperatures, often up to 530°C–650°C (1200°F+) for specific chrome-moly steels. How Molybdenum Enhances Heat Resistance: Increased High-Temperature Strength: Molybdenum improves the creep limit—the ability to resist deformation (stretching) over time under constant stress at high temperatures. Reduced Softening: Unlike carbon steels that lose strength above ~400°C, molybdenum inhibits softening and keeps the steel tough. Microstructure Stabilization: Moly slows down the agglomeration and coarsening of carbides at high temperatures. It forms stable carbides that strengthen the grain structure. Improved Corrosion/Oxidation Resistance: Molybdenum contributes to the formation of a stable passive film, preventing oxidation and corrosion in high-heat environments. Key Applications: Chrome-Moly Steel: Widely used in power plants, oil and gas, and petrochemical industries for its ability to handle high-temperature and high-pressure environments. Aerospace & Automotive: Used for engine parts, turbine blades, exhaust systems, and brake discs. Tool Steel: Molybdenum-based tool steels (M-series) resist softening at high-speed cutting temperatures. While molybdenum is often added into the steel during the manufacturing process for the best structural results, specialized thermal spray coatings of molybdenum are also applied to improve surface wear and high-temperature performance. "
How often are you going to add, would it be better just to use an oil that has a higher Molybdenum level?
Motor oil that already has it should do fine. Valvoline Restore & Protect motor oil has it and has 5 star reviews on Amazon. It claims to "restore" the engine and protect it from future wear. Check if the one you use has it. Valvoline Restore & Protect Full Synthetic 0W-20
The Motor Oil Geek used Valvoline Restore and Protect on a 500k mile engine and shocked to see the rings clean and unstuck after one oil change at 5k miles. Valvoline Restore & Protect Full Synthetic 0W-20
The steel part of the head gasket does not fail. It's the black coating that breaks loose on the original gen3 hg design. Unsticking oil rings and clearing oil return passages won't fix weak low tension rings. New redesigned Toyota pistons and rings solve excessive blowby and oil burning.
Lots of models are experiencing worn and stuck piston rings. It doesn't hurt to give it a try. A lot of comments say oil burning has been reduced a lot from both Liqui Moly mos2 and Valvoline Restore and Protect. The key is to first removed as much carbon build up as possible so that metal to metal contact can take place for moly to do it's job. Which is why I'm adding Sea Foam to the engine each oil change. As well as to gas. Anyone burning lots of oil who doesn't want to rebuild their engine should consider giving Valvoline Restore and Protect or Liqui Moly anti friction with some Sea Foam a try and over time tell us if oil burning has been reduced. A lot of Amazon comments are saying oil burning has been reduced. Head gaskets fail mainly because of excessive heat. Anything that can reduce heat, especially if moly helps reduce friction may be all that's needed to prevent real failure. A completely blown head gasket. My first experience was when I was 17 driving in my friend's car when the engine failed from over heating. I had a mechanic family friend that helped us completely rebuild the engine (in our driveway) which was warped pretty bad. So I don't want to see that happen again.
I know this is from a Gen 2 Prius owner, but still impressive results for Liqui Moly MoS2. Also regarding K&N. Imagine if you are running with a heavily restrictive mask. Less air intake means more struggle to breathe. More struggle means more heat build up from more RPM. It's all about keeping heat down.
Would it hurt to leave the seafoam in the oil for 5000 miles or just the 500 miles before the oil change?
Toyota spec’d low friction piston rings, likely to eke out better mpg, at the expense of reliability. They finally revised them, halfway through model year 2014 (next to last year of 3rd gen). Their decisions are our legacy. look at the 3rd gen fuelly mpg averages by year: earlier years average around 44.5, while 2015 is 42.8. My 2 cents: the head gasket fails due to engine overheating. Overheating is due to lean air/fuel ratio, which is supposed to be mitigated by a properly functioning Exhaust Gas Recirculation system.
