Turbo issue

After my salesman conceded to me that management was aware of the issue, he assured me that they would "take care of me with a loaner" in the event I had problem.

As to the intent of the thread, go back and read post 1. OP was seeking information on the nature and extent of this issue in order to make an informed buying decision.

 

Servo driven wastegate should not have a spring. The ECM can control the rest position of the wastegate. Remember, the wastegate had a fault, and safe state for a faulty wastegate is an open position, so the ECM is likely going to leave it open, intentionally.

If there was a spring return to close, that would create two unwanted issues:
1- you don't want a faulty wastegate defaulting to a closed position, it's unsafe for the boost control.
2- a spring would be fighting the servo, the servo needs to quickly move the wastegate constantly, having a spring to contend with would create issues for servo driven actuation.

 

It took two weeks from drop off to "fixed."
Fingers crossed turbo issues won't reappear!

The wastegate was opening too far, or beyond specs causing it to stick and throw a CEL.
Apparently Toyota is aware, and they're working on an ECU flash to update wastegate duty parameters.
The turbos themselves are fine, and are functioning in parallel to each other, not sequential.
They have no clear answers for the following questions, "So can it happen again? Why is it consistently bank 1 wastegate and not driver's side? When is the flash being released?"

 

...or all my guns....

 

Never going to see a software update for this because it’s not a software issue. Everyone would be affected if it was.

The wastegate can’t open too much because there’s a physical limitation on wastegate open. You can see in your third pic that there’s a boss on the turbine housing and a tab on the actuator arm that will come in contact when the wastegate is fully open. What’s happening is that the wastegate is sticking or the actuator is not providing enough force close the wastegate fully at max duty cycle. The CEL appears after the ECM notices that the commanded wastegate position isn’t being achieved. There is should be a maximum amount of current that feeds the wastegate actuator and if that level of current can’t actuate the wastegate, then software can’t fix the issue. It becomes a wholly mechanical problem (either on wastegate or actuator).


Clockwise is open and counter-clockwise is closed.

 

Interesting. Not discounting you at all because my truck is currently at the shop with the same issue, but if it's a software issue it seems like the issue would be more prominent and if a software update is the fix I would have thought Toyota would have just done that rather than spend money replacing turbos.

 

Makes sense, I hear ya.
I'm relaying what the tech is saying, so take that for what it's worth.
A rep who's visited my dealer claims it's as many as 1/5 trucks being affected in her region. If that's even close to being true it's shocking.

 

Yeah the dealer I took my truck to said this is the second one they've seen with the turbo issue, but we really haven't been getting many trucks in NC either. Mine was the second one I've seen on the road out here. So the numbers could go up.

The part I'm now trying to figure out is what kind of loaner I can get. I was given a Camry, but with spring amongst us and yard projects I can't really haul stuff in a Camry. Dealer is working with Toyota to get me into something bigger, but we'll see.

 

Oh, you can haul stuff in the Camry. Just start shoveling landscaping materials in the trunk and back seat. Maybe that will hurry the repairs along.

 

I've seen people at HD load up a Civic coupe until it was on the bump stops, then they loaded some more!

 

Civic still has more payload then a 2nd gen

 

It could potentially be that the actuator limit values are beyond what the stop allows. So the actuator is still trying to move against the stops. This could be damaging the actuator and cause the grinding sound that was posted about earlier.

That'd be the only way it would be software. But as you said, how could something like that only hit some trucks but not all

 

Since everyone is posing theories, I'll pose one. It's both hardware and software, if the actuator goes too far, hits the stop, and tries to keep going, the current draw on the circuit will go way up. Since any motor has something that limits current between it and its current source (a fusible link for example), the high current takes this current limiter out and the waste gate is stuck in its current position, open or closed. That would drive the hardware replacement, and future failures avoided by preventing the waste gate from going too far through a software change. Why it would travel too far in some cases and not others is still an unknown. If you go back to the days of breaker points a couple of thousandths off can make a big difference.

 

sweers is that you?

 

No, I was a forestry major.

 

Maybe but based on the stop positions (wastegate stops the fully closed position and the tab stops the fully open position), the ECM knows where open and where closed positions are and there’s an active test of the wastegate positions at idle. If you have a 22 Tundra you can hear and watch the wastegates actuate if you wait long enough after starting the engine. So it finds open and closed positions at every start. It seems most people have this issue pop up during driving so that must mean that the problem is not about limits but about trying to get the wastegate to move at all.

The ECM would control the current likely. The draw is probably something like 1 or 2 amps which is pretty small. The ECM behaves like the fuse. It commands a certain position, provides voltage or current to move to that position, and trips the CEL if the position is not achieved.

 

Thanks! Makes perfect sense, please disregard my post. Yours is excellent.

 

Could that mean mechanical binding only at elevated temps and not on a cold turbos at startup?

 

That makes sense to me. Metals expand and it could cause the actuator or the wastegate itself to bind but it only happens on some vehicles because of tolerances.

 

Could software changes fix that?

 

Not confidence inspiring…

 

And Civics are built like a tank. Ours survived two children learning to drive. Engine and drive train absolutely bullet proof. Sold to my brother for his kids and almost made it.....last one got it with an accident.

 

Agreed!

 

Sunday afternoon FB update: SNAFU remains in full effect.

 

I could be wrong but I believe the software fix they are talking about is not a fix at all. If I understand the problem correctly, the issue is the waste gate does not achieve 100% open when commanded to because of a mechanical bind somewhere in the mechanism. The only software “fix” possible for such an issue is to adjust parameters in the software so that the ECU is happy with 85-90% open instead of 100%. In this case the problem has not been repaired and the waste gate mechanism continues to bind every time it moves. I personally would have a hard time accepting a software “fix” for this issue unless they also gave me a lifetime power train warranty. That binding mechanism WILL fail at some point. It’s inevitable.

 

I'm still stumped why it's only one bank. Obviously they're different parts. A left side can't be bolted onto the right side and vice-versa. So is there a different set of machine tools for each side? Different parts bin to pick from for each side during wastegate assembly? It's clear this is not a common problem so something wrong happened once in awhile during the subcontractor manufacturing process.

 

Doubt it. They could increase the power to actuate the wastegate and overcome and bind. But if the actuator or electrical system wasn’t designed for that amount of power, it could cause more problems.

Neither Toyota nor any other manufacturer would ever make that kind of bandaid fix for this kind of issue. It’s inviting more problems form the line. Anyway, based on the TSB that was shared the issue occurs for some as stuck open and for others as stuck closed.

 

I think that the actuator might be least of your worries if that is the case. Limiting the waste gate from fully opening can over speed the turbo and over boost the engine. That is really not good for the motor. Detonation and other bad things. Not sure if there is any other blow off safety mechanism.

 

Bad casting for just that side maybe? The pebbled surface leads me to believe they are cast. Often in mass production casting operations a pattern mold is used to form a tree of multiple castings. Possible just one pattern is a little out of spec on a tree of say 6 castings. Say they are using 4 trees. Assuming QA check misses that bad casting if they are just spot checking you could end up with only 1 out of 24 being out of spec. Just a guess. I’m sure it could be many other things.