Oil Analysis, Redline D6 ATF 30k miles

I think we should all sit at your feet and listen, sir. Seriously, I have only the most rudimentary awareness of the principles, appreciate the in-depth explanation.

In the back of my mind: @Ragingfit did some excellent videos of engine swap. The back story though: he'd done an EGR "delete" about 50K miles earlier, and said as a consequence the engine smoothed out, something like that. Still, maybe he created a time bomb?

Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v | PriusChat

 

But there is an O2 sensor controlling the air/fuel ratio, correct?
And a Knock Detector that immediately responds to detonation, correct?
There shouldn't be any unusual 'Combustion Pressures' happening.

There are engines that operate cleanly without EGR.
There is a system on the Prius engine that will set a code when the EGR is out of spec, correct?

Where did all this thinking come from that the Prius engine needs its EGR system squeaky clean and the
CEL related to a fault in this system is inadequate?

I'm just asking questions.

Is the "Cold Start Engine Knocking' a related problem? Or a separate problem?
Is this knocking where some of the head gasket failures are coming from? "AKA Hydraulic Lock"?
An improved Intake Manifold was Toyota's attempt at fixing that problem, no?

Or,,, is the head gasket just the weak link in very high mileage Prius engines?

I know two bank couriers with >500k miles ea. on their Gen 3 Prii. I'll double check on their EGR cleaning schedules.

 

Do you wait for a light to tell you something is wrong?

If so, you’ll make sure you’re prius has a drinking problem.

An old wives tale for you:

An ounce of prevention is worth a pound of flesh.

 

Give up, Ray...

 

I tried.

Maybe this time it’ll be: message received.

 

This calls for some wine, cheers.

 

How’s the smoke?

Hopefully your not too close to the fires.

 

It's all off-topic too. And I don't know why I'm hanging around, the on-topic topic is hard on my blood pressure.

 

They say red wine cures that.

Or is that those who are connoisseurs ?

Either way, have a glass .

 

My doc says I've got low blood pressure, maybe I'll stick around.

 

I wish I could stay the same.

But @grid will drink to that anyway

 

High blood pressure is better than none at all.

 

Smoke flows in and out through the day, it streams down to here because we’re in the channel outlet. Looks like fog but it’s just smoke hanging around low to the ground.

 

So you'd put up with yours pulling timing and maybe running positive fuel trims until the magic light came on?

There are engines that operate cleanly without lots of modern systems. Arbitrarily removing (or failing to maintain) accessories and subsystems is not engineering. You can abandon a lot of the stuff in your car and it will still sort of work, somewhat. Not judging.

Doubt you'll get much there, they've got the ideal usage pattern to prevent fouling.

 

Good question!
What exactly triggers the CEL for an EGR fault?
Is it only a failed or totally clogged valve and the feedback sensor is showing no opening movement of the valve?
There is no flow sensing in this system, correct?

> These are normal systems that are always running in the ECU background. You have no way of knowing what is the baseline.
You only see your numbers for average MPG and your Oil consumption numbers.
Has anyone posted definitive numbers showing a before EGR cleaning vs after EGR cleaning?
I may do that after gathering before data on fuelly for ~ a year.

>>I agree ! Driving style may be a factor, as I said. Those guys that tip-toe on the Go Pedal to save $0.50 a week and never use high power (high temp / high flow rates in the EGR circuit) with their Prius may be the ones that have the most clogging of the EGR system. MAYBE..... who knows?

My driving style (actually the GF) is mostly a 23 mile commute on the interstate twice a day, weekend highway road trips
(with some 'spirited' full throttle passings and uphills) and some putzin around town, but usually during the commute so everything is warmed up.

Are we really sure this subject is related to Head Gasket longevity?
I suspect the 'Cold Start Knock' is the real issue for head gaskets.

I'm just asking questions.
Sorry if this goes against your strongly held beliefs in all things Prius.

 

I wish I could tell you exactly what trips the ECU for EGR trouble. I'm not aware of any flow monitoring.

I think you are on to something with regards to separating these into discrete problems which may or may not have overlapping symptoms and causes- they are questions worth asking. These things can take on a life of their own thanks to internet forums, for better or worse.

Additionally- I don't have the knowledge or confidence that the ECU is capable of pulling enough timing to fully compensate for the lack of EGR flow in a clogged system. I suspect that Toyota is counting on a fair amount of flow, but this is only my own pet suspicion.

 

It would be a mistake to treat me as an authority on the topic. I'm a shade-tree mechanic at best. I try to keep up and pay attention, but I'm not a practicing mechanical engineer, not by a long shot. It's an internet car forum- you get what you pay for.

People have successfully done EGR deletes on a number of different engines. Sometimes there's no noticeable difference, but sometimes this is only because nobody is building 10 identical copies of it to run through a battery of instrumented tests.

 

This thread has wondered way off topic.

 

That's my take too. If Toyota designs a fairly generous passageway, and now it's 80% blocked up with carbon, that can't be good.

I think you're nipping at their heels.

Agree. I think EGR just has more legs, because it's a tangible problem; it's the Japanese Knotweed of Priuschat, lol.

 

Japanese Knotweed is fun cause they turn it into resveratrol. Let's talk about that next!

Pixel XL ?