Toyota’s stance on using a heavier weight oil

[Brian123]

I think it's a main bearing design flaw,

Think and know are 2 different things!

last I heard.

OK!

 

[edyvw]

If we're being charitable... it could be that Toyota does plan to do something about the hybrids once the non hybrids have been taken care of, however safety concerns would mean the non hybrid should have priority since the hybrid can still drive itself out of harms way if required when the main engine blows and they probably can't fix everything all at once.

That would be my guess. I do think Toyota will eventually get to the hybrids.

Nah. That is wishful thinking that I see on Toyota forums.
What they going to say? Hey remember that engine from 10yrs ago? You still have it?
Toyota overplayed its usual way of doing business. This ain’t first time they left owners hanging dry. Just ask owners of 2017 Highlander and Sienna AWD that had problematic transmissions.
Best advice for hybrid owners, besides not buying vehicle in the first place, is once out of warranty to switch to some Euro 40 grade and pray ever time they start engine.

 

[edyvw]

Think and know are 2 different things!

OK!

It is main bearing issue. There is nothing questionable there.

 

[tired]

Think and know are 2 different things!

That's obvious to everyone? My diction was intentional.

Toyota hasn't released information on what's going on exactly, so it's just been amateurs tearing down V35As and trying to diagnose the issue themselves... This was hard because the engines are replaced under warranty and go back to Toyota, so it's challenging to get an engine to tear down.

"I Do Cars" did an excellent teardown on a grenaded V35A. He tried hard to get one.

 

[PWMDMD]

That's obvious to everyone? My diction was intentional.

Toyota hasn't released information on what's going on exactly, so it's just been amateurs tearing down V35As and trying to diagnose the issue themselves... This was hard because the engines are replaced under warranty and go back to Toyota, so it's challenging to get an engine to tear down.

"I Do Cars" did an excellent teardown on a grenaded V35A. He tried hard to get one.

They did release that the initial fix was a redesigned front main bearing or at least the 2026s have a newly designed front main bearing. I don't know what else we need to know...that's the failure point and they didn't redesign it for giggles.

"Toyota’s May 20, 2026 recall notice says the affected 2024 engines could still have debris that damages the #1 main bearing, and then states: “Engines produced after those included in this recall were manufactured with an improved #1 main bearing.” Toyota also says repaired vehicles from the earlier recall are being fixed using engines produced with that improved bearing."

https://pressroom.toyota.com/toyota-recalls-certain-2024-toyota-tundra-vehicles/

 

[Brian123]

It is main bearing issue. There is nothing questionable there.

Can you explain this, would this issue happen if the engine was not DI. Something is not adding up?

 

[PWMDMD]

Can you explain this, would this issue happen if the engine was not DI. Something is not adding up?

Oiling issue? Material issue? Some actually due to debris while others due to something else? Combination of these issues? You don't redesign the #1 main bearing when that's the failure point unless you're fixing a defect.

 

[tired]

They did release that the initial fix was a redesigned front main bearing or at least the 2026s have a newly designed front main bearing. I don't know what else we need to know...that's the failure point and they didn't redesign it for giggles.

"Toyota’s May 20, 2026 recall notice says the affected 2024 engines could still have debris that damages the #1 main bearing, and then states: “Engines produced after those included in this recall were manufactured with an improved #1 main bearing.” Toyota also says repaired vehicles from the earlier recall are being fixed using engines produced with that improved bearing."

https://pressroom.toyota.com/toyota-recalls-certain-2024-toyota-tundra-vehicles/

I think they were still blaming it on debris damaging the bearing at this point, but I'm no expert on this issue.

 

[Delta]

So is 5W40.
Just wait until they say: Rotella T6? OK during crisis, not after that.
Brotella’s will have a field day.

Wouldn't the T6 15w40 be somewhat acceptable as it's SN rated?

 

[mt23]

Out of curiosity had anybody had one of these engines fail running thicker than 20 grade? I heard they have around 4-5 psi oil pressure hot. Combined with fuel diluted 20 grade and high load, really makes me wonder.

 

[PWMDMD]

I think they were still blaming it on debris damaging the bearing at this point, but I'm no expert on this issue.

I'm cautious about the idea that they redesigned the #1 main bearing solely to handle debris better.

How is debris still an issue? Did they design oil passages that are impossible to evaluate and clean? Is that a thing?

 

[Brian123]

Oiling issue?

You are not sure, that is ok

Material issue?

Again!

Some actually due to debris

The debris thing, really!

Combination of these issues?

Guessing!

You don't redesign the #1 main bearing when that's the failure point unless you're fixing a defect.

Something is not adding up here? The #1 main bearing having a failure, this is pointing out to an oil issue. This is not a thick or thin oil thing, maybe someone letting the oil level getting low, or maybe letting the oil change go to long!

 

[ZeeOSix]

"I Do Cars" did an excellent teardown on a grenaded V35A. He tried hard to get one.

A comment about his discussion at the end about the him not thinking the machining debris was the cause. It's possible the debris was inside the drilled oil channels within the crankshaft, and when the engine was initially ran the debris did initial damage to the crank bearings, and with time they slowly ate themselves and then degraded to the point where they quickly self destructed. Any debris that went though the crank bearings, then would get spit into the sump and be filtered out by the oil filter so nothing major made it to other bearings in the engine.

 

[PWMDMD]

You are not sure, that is ok

Again!

The debris thing, really!

Guessing!

Something is not adding up here? The #1 main bearing having a failure, this is pointing out to an oil issue. This is not a thick or thin oil thing, maybe someone letting the oil level getting low, or maybe letting the oil change go to long!

Yet, while Toyota did release the information on the redesigned #1 bearing, Toyota's official stance still is it's entirely due to debris, so your guess is as good as mine. I give them a mixed score here since they are doing something significant for SOME affected engines, but they still aren't telling us everything going on and they haven't committed to fixing all affected engines.

 

[tired]

Wouldn't the T6 15w40 be somewhat acceptable as it's SN rated?

It was a joke

 

[tired]

I'm cautious about the idea that they redesigned the #1 main bearing solely to handle debris better.

How is debris still an issue? Did they design oil passages that are impossible to evaluate and clean? Is that a thing?

Agree

 

[Delta]

It was a joke

And I had a legit question.

 

[tired]

This is not a thick or thin oil thing, maybe someone letting the oil level getting low, or maybe letting the oil change go to long!

Yeah I'm sure that's what's accounting for the widespread failure. Toyota need not worry. We have @Brian123 on the case.

 

[tired]

Wouldn't the T6 15w40 be somewhat acceptable as it's SN rated?

Sure yeah run it.

 

[edyvw]

Can you explain this, would this issue happen if the engine was not DI. Something is not adding up.

DI or not. It is bad design. It is I think oiling issue. There are several good videos that explain issue.