2GR-FKS burnt valves and blown gaskets octane related?

nope. hell mazda runs around 14:1 compression safely on 87oct gas nowadays.

these catastrophic engine failures are extremely uncommon. this engine has been on the market for 11 years now and has proven itself very reliable.

nearly everyone i know with these runs 87 but i know for a fact mine ran better on 91. i am on a 91oct specific tune now so it is required for me.

 

I don't think people are frustrated that failures exist, especially when there are probably 1.5 million V6's in the Tacoma out there. Failures are normal and will happen. However, it is slightly depressing to see the same failure keep popping up in every single year model. In small numbers sure, but we don't know all of the failures that occur either, and we are only up to today; they are not done happening. There have been some cylinder head part number updates over the years, but nobody knows what changed and if it actually made a difference. Same concept as the ACIS flap falling apart, the same timing cover design leaking, same coolant pipe cracking (although they did update that one at least), and the high pressure fuel pump chirps/leaks. They're all still "rare" failures but they are very real problems for those they happen to, and Toyota has done absolutely nothing to address most of them.

It would just be nice to know why these specific failures occur...nobody wants to drop $6-8K for their engine to be opened up for this, especially because what if the new head/valve(s) do the same thing again? The design hasn't really changed, so aside from luck, how much confidence does installing a new head/valve of the same exact design for $6-8k of your hard-earned labor really yield?

I don't really factor in the success of the 3.5 overall, because this issue only seems to happen on Tacoma and Highlander versions. Obviously still a lot of vehicles between those two, but it narrows it down a lot to cut out all the others that have no documented failures of this type.

 

One could argue that about failures on vehicles across the board, the truth is at the end of the day they are in the business of selling vehicles, if every vehicle lasted 300-500k they wouldn't be selling many. If they can make them "good enough" that the vast majority make it beyond the warranty period without any major issues that's a win for them, once a vehicle is out of warranty I really believe a manufacturer could care less if something breaks.

I'd argue Toyota has held onto putting more effort into design quality longer than most manufacturers but even they are succumbing to the effects of materials cost/quality, meeting regulations, and trying to remain competitive, this equates to quality and longevity going downhill IMO.

The most notable failure I see all the time that the manufacturer never did anything to fix and I'd argure actually made later models worse is the GM 6L-80 transmission found in most 07-18 GM 1/2 ton trucks and SUVs. The programming that locks up the torque converter in as low as 3rd gear combined with a very thin and flimsy torque converter clutch means a very sizable percentage of them shell out the torque converter clutch which takes out the pump and the rest of the transmission typically in the 100k-175k range on 14-18 models. GM has never updated the programming to extend transmission life or put in a beefier TC clutch but they will happily sell you another transmission with the same design flaw for around $4k.
Aftermarket companies have come out with a better design torque converter and there is aftermarket tuning to help extend it's life but GM has never addressed the issue.

 

I was going to mention the skyactive engines but only have anecdotal evidence that they are as reliable as anything else. But yeah, when modern turbo diesels run 16.5:1, 14 on a GDI engine is pretty high.

Agree with what you said and it sucks to be one of the few that are having the problem. I'd be pretty pissed if it cost me $6-8k. Reality is, I'd ask to patch it up as best as possible and unload it at Carmax. I imagine for a company like Toyota, with their kaizen and six sigma concerns, they keep track of this. They probably had engineers take a look at it already and project whether this is a real problem or not. Since there hasn't been a recall or TSB, I'd guess this is tens of people not hundreds of people?

 

Ive always used 91+ octane in all my japanese marque vehicles.

They run better and get better fuel economy. I will keep doing what im doing.

 

My truck runs best on Shell 93 octane. Every vehicle is different.

 

But isn't in USA all gas is coming from same vendor? and they just add stuff for top tier guess? I mean like Octane 87 still has minimum requirements of some quality? It can't be that bad.


I have never put non top tier before, I use Exxon & Shell mostly, Sunoco , BP etc sometimes. I want to try premium but dont want to cause issues

 

What issues are you concerned about?

The manual clearly states to use 87 or higher.

I can almost guarantee your truck will drive better on 91+ octane.

 

Ive never ran 91+ octane before, and I don't know how it will affect the engine ,don't want to fk something up. I might try I guess, I will try to maybe add half tank premium see what happens. I dont want to pay extra if it doesn't do any good for the engine. The Exxon premium does state it keeps engine 2x cleaner or some bs so if it really does its fine to me

 

Did you read my post?

The manual states that you can run 87 or higher.

 

It will be perfectly fine to run higher octane.

 

Locally, we have a retailer that sells ethanol free 89 octane, which is what I run. I get better gas mileage with this gas. To be honest, the increase in mileage isn't enough to justify the cost, but I don't care, I like how the truck runs with it. When I'm out of the area, I run 93 if it's ethanol free. If I have to run ethanol, I'll just run 87 and live with it for a tank.

 

I installed the RIPP performance ignition coils, a cold air intake and an oil separator to clean up the crankcase gasses before being pumped back into the intake. All of this for a cleaner burn. I do run 91 octane. Ill have to wait to see how all this turns out

 

Having been an aircraft mechanic for years, you can buy AvGas at any of the smaller type regional airports. The LaGrange municiple airport actually has a pump you can drive your truck up to and pump your own . 100LL octane, ethanol free
"WHOA NELLY" $6.50/Gal

 

The GR V6 was originally designed to run best on premium fuel, so I've always run premium (91+) on my Tacoma, 4Runners, and our XSE V6 Camry. The engine can of course run on regular which is what Toyota needed as a mainstream brand, but Toyota engineers will tell you it runs best on premium and can run on regular: More power, greater efficiency, less knock. Most folks want to spend less on fuel and the GR can do that just fine... if you care and it matters, run premium.

 

Yes in my opinion spending little extra on little things matters a lot for the longevity of the vehicle. Like buying OEM oil filter instead of spending 10-15$ less on FRAM and putting engine at risk. So I will try to run Exxon or Shell premium and see how it does

 

I run 87 octane for most of the time, primarily for the lower cost. I've put in a couple tanks of 91 or 92, and immediately noticed a difference in engine power management, especially at highway speeds with moderate slopes.

The ECM clearly adjusts the knock correct learn values, intake VVT angle, exhaust VVT angle, and ignition timing when a higher octane fuel is used. My guess is that with less knock, it can tune itself for more power. But drop down to 87 octane, it needs to reel things back to prevent knock.

On my last road trip, I watched my OBD2 Fusion during "high load" moments on the highway (5th gear, slight incline, 70 mph). My intake VVT angle went up to 76 degrees, and exhaust to the low teens. In "low load" situations, those numbers seem to reverse. Food for thought.

 

I had the problem at 42k miles, bank 1 cylinder 3. 120psi leak down. The CEL first appeared after I ran 3/4 of a tank of 92 octane. It was the first time I ever used premium gasoline I only used 87 before then… those are the facts I can offer.


As for my opinion- I think the computer added timing due to the higher octane not knocking, in an attempt to increase efficiency and performance, which caused a valve seat or valve to fail.

 

What is kclv value are you getting on 91+?