I Do Cars just posted a teardown video of a 38k mile Tundra engine with the main bearings failure. I see several things not to like about the design. One glaring issue and design failure is the dual fuel injection system doesn’t seem to be doing its job at washing the valves. Also, take note of which bearings failed and which didn’t. There’s a clear directional pattern following oil flow (I think) related to the bearings that failed. Another thing he points out is thrust related wear on the rods and the thrust bearing design. Not good. Have a look and you and some other knowledgeable guys can discuss it. I am not convinced the failure was all machining debris related in this engine.
Tundra V35A teardown video (I Do Cars)
Started by duggydo · November 30, 2025 at 7:53 AMduggydo
OP
TheCarGuy
Yup I agree, TCCN also mentioned that the port injection doesn't really seem to be helping/fixing the DI carbon issue, so then you get the complication of port + DI...without the benefit.
I don't think it's all debris, I agree. Toyota went into more detail in their latest recall on their investigation, they were investigating known good engines again which tells me they really don't believe it's just a debris issue either.
It's very odd that the main bearings are always the culprit, nothing else looked bad or worn. Most of the higher mileage 3rd gen tundras we see are highway/hot shot style driving, less top and go and less high torque situations, though it's odd that many have over 100k miles with the same supposed design flaws. There are some theories about higher oil pressure/less start stop activity with these high mileage units as well.
I did ask Eric from I Do Cars if he'd do a video/interview with me, we'll see but he's a busy guy so I'm guessing he might not have the time.
duggydo
It’s actually a bit absurd that they have been so secretive and arrogant about this whole situation. It’s wreaks of big corporate politics. I think they should have enlisted some independent testing or released more of the failed engines for other companies to look at. Committing to the multibillion dollar recalls without full confidence in the root cause is ridiculous. It doesn’t surprise me though. When I was still in the corporate world doing engineering work, we were often directed to do stupid shit from executives three or more layers of management away from us. I bet something like that is happening in Toyota.
TheCarGuy
Agreed. I see the same thing where I work now, 2 or 3 levels up making poor decisions, everyone is just forced to carry it out or...leave.