P11EC00 error code update

I’ve seen two 2020s. I haven’t seen any 2021 or later. I’m not a Toyota mechanic or anything, but just what I’ve seen here and FB. From what I could tell the 2020 here and the one on FB were different. I’d imagine time and mileage are part of it, but we’ll see.

Looking at the cyl head part numbers it didn’t seem like the current version of the head was any different than the earlier trucks. So I’m not sure anything has been updated in all this time.

 

Just thinking out loud here...
When it comes to burnt valves, stuck valves etc, I am more familiar with air cooled aircraft motors... (where this kind of crap happens about 1000 times more often I think).

I wonder if the some of the aircraft diagnostic methods can be used. On aircraft motors, the exhaust valve should have a bullseye heat pattern typically, it would be interesting to see if a hot spot are visible on these valves before they are irrevocably damaged. (Anybody know if car valves are set up to to rotate slightly on each operation like aircraft valves.) Anybody tried to get a borescope down one of these insanely deep plug wells?

Wonder what the valve guides on this motor are made of, normally valve guides seem to wear alot more as a valve is getting a hotspot, and can be somewhat detected with oil analysis...

 

Yes, I came to that conclusion too after learning more about it.

 

https://www.youtube.com/watch?v=oULcpdL3Tss This is a great video that shows what goes into building our engines

 

It’s blowing “clean” air back into the intake though. So don’t think it adds to the build up.

 

None of the possibilities you list are unique to Cyl #1.

And yes, they may know but the correction is more than the repairs as it would have to be done to far more vehicles.

 

It's not that clean, check out this picture of my intake.

Many Tacoma owners aren't aware of this problem so how do you know it's not happening with Lexus vehicles?

 

I work at a multi franchise new car dealership , one of our brands are Lexus , plenty of leaking timing chain covers but no burnt valves to date ( shop Forman is a friend of mine , worked with him for 30 years now)

 

Obviously I can’t say that zero Lexus vehicles have had the failure but we service probably 50 lexus a day and we haven’t seen any

 

Always appreciate hearing first hand knowledge. Too often all we hear is second and third hand and that's generally not that accurate.

 

By clean I mean air that hasn’t been through the combustion process yet. It was fresh air from the intake sucked in on the intake stroke and blown back out on the compression stroke.

 

Did they give you any pics of the valves as well?

This thread has me rethinking catch cans.

 

I’ll throw this out, based on experience with another engine entirely, a port injected Chrysler I4. Had one of these burn a valve probably 10 years ago. Under warranty, probably 30k miles. Talked to the tech and he said this is very common for those engines since gas had switched to E10, they saw much more carbon accumulation and once it gets so bad, it will foul the seat and burn the valve. So I’m wondering 1) is there proof that there was really a lean condition in cyl #1 or is that a theory and 2) could this be related to fuel with higher E value?

 

Sadly no. I'm going to see if the tech has any insight into where around the perimeter was the valve leaking.

That's a very interesting observation and it may have some relevance to this issue. I'll be researching it further but it doesn't offer any explanation as to why Cyl#1 but it may be just like stress testing a chain until failure - only one link fails. You can't continue the test on the entire remaining chain for the next failure. And once the failure occurs in our trucks, they are not likely to drive another 10,000 miles or so to see if another exhaust valve begins to leak.

 

Yes, it is a 4DS engine like the Tacoma.

 

I have good news - I spoke to the service manager for the dealership (not the service agent I mentioned earlier) and newer Tacomas have redesigned heads and the older ones that are being serviced under warranty also receive the new heads. And the difference is in the valve seats for the exhaust valve. He was unable to detail exactly how they're different but it has to do with the configuration and machining of the valve seat and it is a direct result of the failures we've experienced.

So those that have speculated it wasn't a lean mixture or injector issue were on the right track. It also could have some correlation to E10 fuel but that is unknown.

 

Any chance you have any part numbers? I’ve tried looking up the part numbers multiple times on multiple sites but couldn’t come up with more than “this cyl head fits 2016-2022”, or similar. I couldn’t find part numbers by year, or what year any updates were implemented, or anything like that.

At least, I couldn’t when I was looking into this back in August or so.

 

I really hope this is the case , I must admit I have some reservations with his claim of a redesigned head . That would be great news indeed

 

No and nothing on this invoice for my truck has any part numbers. The service agent at one point says the number is unchanged but I question whether he really knows that for a fact as he's not the one that actually places orders for parts.

He was describing what the Toyota regional rep was telling him. He related that Toyota had been working on the issue for some time and this was the final resolution.

 

Part numbers are probably the same, the iteration will be different. Like VW Audi use letters to show which iteration (rev change) for their parts.