2GR-FKS failure at 150K, looking for input/some questions

So, all you've got to back up this statement is a bunch of actual facts? That's not how it's done on TW

 

Anything can happen... It's a machine. I had a 4.0 spin a couple crank bearings at 93k! Oil changes every 5k always synthetic. Shit happens.

 

Both are very reliable, just need to be mindful of what the design intent was for each motor - I think the best comparison between the two is the 3.5L is a car motor whereas the 4.0L was designed with the intent of it being a light truck motor. The bore & stroke of the 4.0L is slightly over-square whereas the 3.5L is decently under-square in the design and each motor demonstrates this in their performance. Look at the applications of where Toyota chooses to use each engine around the world:

4.0L 1GR-FE= Hilux, LC prado, LC, 4runner, etc
3.5L 2GR-FKS = camry, highlander/kluger, sienna/alphard, etc

It'll be interesting to see what Toyota does with the new 4G Taco. Rumor says it's supposed to use the new 2.4L Turbo 4banger out of the Lexus NX350 and seeing how the Tundra is running a 3.5L Turbo V6, it seems boosted smaller displacement "car motors" seem to be in the works for the future of the Tacoma. Hopefully they'll gear it properly and learn from the shifting problems. Maybe we'll get lucky and they'll bring Hino back to help with the design.

 

Sienna has more payload than any gen Tacoma, yet Toyota uses 3.5. 2GR fks will be just fine.

 

More facts, careful or you will get both of us banned.

I can agree with this (they do use the 3.5 in a Prado for the Chinese market), but I don't think it was a necessarily a poor decision. They got more HP and torque out of it, although at slightly higher RPM's. I've owned two 2nd gens with the 4.0 and we currently have a 4Runner with it as well (and an '06 with the 4.7L V8, sure wish that was an option). The 3.5 feels significantly smoother and more refined than the 4.0, especially if you lay on the gas, but overall feel of power is about the same. Slightly better MPG in the 3.5. But neither are a smooth as the 4.7.

 

Haha I have to say, my current 4.0L seems smoother to me, but that might be a product of how the trans shifted on the 3.5L, even after being OVTuned. My old one 3G always seemed torev hang like a MF'er and made for a somewhat jerky experience, especially when feathering the gas over rocks and ruts on a trail.

Definitely agree the power feels about the same though, I was very surprised by that - I thought it was going to give the typical "gutless" feel of the 3.4L. 4.0L reminds me of the 3.4L in the noise and vibration for sure where as the 3.5L feels a little more modern, newer, etc.

 

I saw a new 4.0 as a base model option in one of the leaks.

I can't find that now.

 

Huh. Imagine that.

 

1GR was used in the 4runner since 2003, so you were correct when you mentioned they used them elsewhere first

 

same my fathers 4.0 isnt as smooth and runs out of breath earlier at higher rpm

 

Toyota could take the 2gr-fks and increase the stroke to get 4.0L, and not change anything else and some people would eat it up saying stupid stuff like "they finally put a truck motor back in the Tacoma..... rawr, rawr, rawr rawr!"

Most of the disappointment in this engine is really from how it was tuned with poor throttle response. I drove a rental Escape the other day and noticed it was programmed similarly.

I think for the most part, the 2gr-fks will end up being a pretty reliable engine in the Tacoma. It's been out long enough to see if there really is a big problem. There will be some failures, but there hasn't been an alarming number of them.

 

Well let me tell you, I was not expecting so many responses on this thread... I honestly haven't read most of them yet but figured I'd give y'all an update with recommendation listed below. Please read, it's actually been an interesting learning experience so far. No conspiracy theories, I just want to be in my truck again. 20 miles before the engine went I installed a set of Dakar Springs in the back and king springs over custom Bilstein Coilovers on the front and Pro Comp UCA's to sit Hankook At2's at 32's with 1.5" spacers all around to offset the lift. It felt pretty good goin down the road, let me tell you.

So on the Toyota side, no chance for dealer or Toyota corporate help since the truck is well out of warranty at 158,000 miles and 150,000 miles is about the expected life of the engine (this is according to Toyota USA, more on that below).

I've met with a few shops to see if I could vet anyone who would want to work on my engine since the 3.5 needs to come out to remove the heads and for the 3.5 to come out the trans has to come out and the whole front support needs to be removed as well and I'm not down to try and do that in my driveway.

The information various performance and reman shops in the LA/OC area gave me are as follows:
The 2GR-FKS is an almost identical casting to the 2GR-FSE in the second gen with the exception of a revised top end to increase compression and fit the new VVTI-Wide system. Since they are an almost identical casting in the bottom end, it has similar issues to the FSE specifically relating to minor design flaws regarding oil flow. Like the FSE, some FKS engines (not ALL, not trying to start a war) have trouble supplying oil to cylinder #5 which leads to overheating of cylinder #5 that increases the possibility of rod failure which can in turn lead to associated damage to cylinder #6 and potentially damage the heads through contact (lost rod throws piston into head, despite non-interference setup). Another problem that the FKS can have is relating to improper servicing of the new VVTI-Wide system at the end of its service life. Timing components are rated for a life of about 100,000 miles with a serious risk of failure of timing components after 150,000 miles.

So this is what I'm betting happened to my engine based on the information I was provided and the experience I had with the motor:
My 2GR ran very well for all miles up to the last couple weeks of its life. Oil change intervals were 3,000 miles With filter every time and 91 octane fuel during long trips to help with injector cleaning. Spark plugs and coils at 65,000 miles. I installed a custom air-oil separator early on and regularly found about 16oz of oil every oil change which was normal given the VVTI system (VVTI systems cause a huge amount of blow-by on current engines, I wasn't too concerned).

At around 157,000 miles I noticed the truck started having an intermittent idle on start up and when stopped in traffic. I changed the oil and filter and found about 32 oz of blow-by oil in the separator. This paired with the idle issue suggested to me that there was likely a vacuum leak in the system so I started the journey of hunting the leak down. After replacing hoses and clamps and testing for air leaks, I found nothing so I moved on to the next possibility which was fuel delivery issues or spark issues. I purchased spark plugs and coils to be ready to change them out after I returned from work (I work forestry so I'd be gone from home in the truck a few days at a time) and since I wasn't able to tackle the spark before leaving I figured I'd toss a can of injector cleaner in the tank with 91 octane for the trip to see if it cleared up and the next morning on the road the engine gave.

So what MIGHT have happened??
Based on the information I was given, something that stood out to me obviously was service intervals for timing. At 158K miles, I was in the red zone for timing and head overhaul. The 2GR FKS is non-interference, so timing issues shouldn't necessarily cause damage within the cylinder. I was able to pull the valve covers to look into the guides and cams and found that the timing chains were still intact but spark plugs in cylinder #5 and cylinder #6 were real smashed up suggesting the rod in cylinder #5 likely gave throwing the piston into contact with the head and throwing off the crank balance sending piston #6 into the head after associated rod failure.

I think what happened was a worn timing system lead to an intermittent idle convincing me of a non-timing issue. When I ran 91 octane with a fuel cleaner, I increased the fuel burn in the cylinders which upped the operating temp leading to an increased overheat of cylinder #5 (unidentified underlying issue). This overheat paired with misfire from the worn timing system pushed the rod in cylinder #5 past its limit leading to failure of the rod throwing the piston into the head smashing the plug and causing a resulting failure of rod #6 to a similar result.

Given this, it's possible the heads are cracked or at the very least bent valves and fucked guides. If the cylinder was overheated its likely the hone is scored, and the fks would be tough to try and overbore. So I could try for a rebuild or at least a teardown to determine what happened or toss a used motor in there and figure out a revised sump system with a large cooler to increase the amount of oil available in the pan. For folks who experienced cylinder #5 starvation during off-road inclines (white-smoke fiascos), an oil pan baffle might help limit starvation by stopping lateral sloshing of oil in the pan.

Another fun thing I noticed in taking the valves out is the setup of the HPFP.
The pump actuator spring sits on a fixed follower that has a hydraulic roller attached to it that rides directly on the exhaust cam on the passenger bank. When I pulled the assembly out, all the gunk from old oil had accumulated on the roller which caused some scoring on the center of the roller, so that's what that "ticka-ticka-ticka-ticka" sound is when the motor runs. Overall though the setup didn't seem too bad, just maybe need to shorten oil change intervals and find a good oil cleaner that works with the pump assembly.



Important things to take-away:
1- Toyota USA identified the expected life of the 2GR-FKS motor to be 150,000 miles which should be useful to know whenever you're handed the "should
last the life of the engine" line.

2 - The top end and VVTI-Wide components need to be overhauled/replaced (timing) BEFORE 150,000 miles to avoid timing failure.

3 - If you start getting an intermittent idle at any engine mileage, start a claim with your dealer's service department. Diagnostic is $150 (sellout, I know).
Toyota USA made it VERY clear to me that if I had brought the truck in for inspection prior to the failure, they would have considered helping with repair or
extending the warranty. At the very least, you'll have a paper trail that can come in handy if a TSB or class action is ever out for the oil starvation issue.

I'll likely be going the used motor swap out route to minimize cost and avoid a core charge for the old motor. When I get there, ideally before the second week of January, I'll be able to update on the continued teardown of the motor. But I'll probably start a new thread because this one got... crazy

Let me know if you got any thoughts.

 

3k oil changes since new?

 

Yep, my first new car purchase and I wanted this puppy to last. The service manual calls for 3k oil change intervals if you regularly drive highway miles, have a roof rack installed, tow weight or have payload regularly in the bed.

 

Worn timing system? None of this even makes any sense. If it jumped even one tooth, you would know. And if you kept running it to blow a rod up (pretty sure it would destroy a piston before a rod), you're kindof...not smart.

Edit - to add - this doesn't use VVT-iW. Just standard dual VVT-i. Nothing new about it. Been used in MANY 'yota engines. Since 1998.

Edit again - Maybe i'm wrong on that last part - looks like it might use that for the intake side?

 

okay

 

I'm a bit lost too, tbh. None of it really adds up in my head. But I'm definitely no expert. Maybe @EatSleepTacos or @WarFab Armor

 

"The 2GR-FKS engine is a 3.5-liter, 24-valve DOHC V6 engine. This engine uses a VVT-iW (Variable Valve Timing-intelligent Wide) VVT-i (Variable Valve Timing-intelligent) system, DIS (Direct Ignition System), ACIS (Acoustic Control Induction System) and ETCS-i (Electronic Throttle Control System-intelligent). These control functions achieve improved engine performance, fuel economy, and clean emissions."

The VVTI system in the FKS is revised from the FSE, VVTI systems have always been a part of the 2GR family, this system is the new iteration. Sorry I'm not Smert enough fer ya bud.

http://www.toyotareference.com/guts/tacoma16_engine.pdf

 

I wasn't saying timing skipped a tooth like homie said, and homie I'm not shooting back at you. VVTI systems use oil pressure, solenoids and sensors to adjust pressure regulated sprockets to advance and retard timing. Thats the whole Otto VS Atkinson system Toyota was always going on about. These moving parts tend to clog in the oil passages or wear (metal on metal, plastic and hot oil, etc) on pressure loaded systems that make the mechanical timing vary slightly from what the ECM is expecting or reading. When these readings are off you'll get issues with your AFR which can lead to misfires.

Misfires are the critical problem as they can lead to heating issues. In the case with any engine, not just the 2GR, an increase in cylinder temp can lead to detonation which is an engine killer. Misfiring would definitely increase stress and if the cylinder #5 was already weakened from "normal" overheating, detonation would be enough to cause the rod to fail sending the piston into the head. In the 2gr the rod tends to be the weak link for some reason.

And yes, please. If anyone knows engines pros for the FKS or FSE I'm definitely looking for more experience.

https://www.youtube.com/watch?v=LuWO2Dyt0EI heres an example video for the 2gr fse (2nd gen 2gr) if you look at where the chains attach, that sealed looking cylinder is the timing cam sprocket. It's internals expand and contract depending on oil pressure to advance and retard timing. Like any moving part, it will wear over time.