Replaced complete EGR system w/photos

To paraphrase HAL, this conversation can no longer serve any useful purpose.

 

I feel sorry for Mr Bill. He can't read my links and he thinks the Prius comes equipped with a carburetor.

Pixel XL ?

 

To save a noob $600 - 1300 dollars on questionable 'Preventative Maintenance'.
That is my 'Prime Directive', Dave.

Of course I think the Prius has a carb. There is NO. Other. Way. to mix and control the Air / Fuel Ratios!
Yes, yes, your links to research into ERG and what it can do at extremes....

Now, explain to us how some car manufacturers use it and some do not?
In a few paragraph tell us how the Prius engine goes dirty/dangerous to the head gasket when the EGR circuit starts getting choked down,.(it ALWAYS DOES).
Head gasket it the end game in this discussion, correct?

mjoo, I'm sure you have good intentions beating this drum for a squeaky clean EGR circuit,
but this is not my first rodeo with leading edge cars, which to me, the Prius is !
Tell us about your background for making these claims of doom if the EGR is not perfect.

TLDon'tR. My background into being a myth buster.

I cut my teeth on British sports car beaters! I know SU carbs like the back of my ****.
>Moved on to various VW's with the simple, basically mechanical, K-Jetronic constant flow Fuel Injection system.
I worked at an sports car shop that got most of the D-Jetronic repair work in town.
Thought I'd try a brand new car when I got a job with an airline!
>Bought a new '86 Dodge Omni GLH. Fun, fun car for the day! A GTI spanker! But it had a carb, one of the last.
The next week the faster GLHS came out with a turbo and fuel injection. I was pissed.
Unfortunately it was a 25 mpg hiwy rated car.... I had a long commute...
So I traded it for THE new Fuel Economy Champion:
>'89 Geo Metro Base, rated 58 mpg hiwy!
I was a responsible new father and kept that little un-air-conditioned sucker for 13 years/240k miles.
Always used M1 and it was not using oil when I sold it, but it was getting ready to rust in two.
>Then I tried a '93 Honda Civic VX rated at 51 mpg hiwy. Rare expensive model, 1% of production.
It had an expensive '5 wire Lean Burn O² sensor'. Loved that it had AC!
>Tried 2 different VW TDI diesels bc a friend had converted a MB diesel to a 2 tank system to use heated filtered waste vegetable oil. I wanted in on that greasy gravy train! But I only used WVO in the summer heat mixed with diesel. Loved the economy and technology but got tired of dikin with all that smelly stuff. (The 1st throttle-by-wire?)
>Got a used '10 Prius IV w/solar sunroof and was living in the future!!! Loved the tech!
It gave me a taste of what an EV could be,,,all of 1 mile,,, so I moved on...
>Got a new/demo '13 Chevy Volt and was living in the future!!! Ta'hell with gas stations and OPEC!
and enjoyed road trips with its rated 38 mpg. It gave me a taste of REAL EV, (The Prime is not that), so I moved on.
>Got a used '14 Chevy Spark EV, cheap with 3500 mi. I'm at +60k miles. Living the future! Ta'hell with OPEC.
>Recently I bought a cheap, fantastic '11 Prius Level V w/ATP, with 183k mi for the GF and road trip use.
Love the attempt at Auto Pilot tech! Still hate OPEC.

And now I'm back on this forum, asking why are a few people saying, "You have to keep the EGR clean or,, bad things will happen"...

 

My foray cost nada. OP went full retail which is very frustrating, not needed. But that's water under the bridge, done. Well, for most responders. For you, it's ammo.

 

Yeah, the full retail approach is a strange way to make those parts clean.
I will take the FREE route when that day comes,, if it comes.

Not ammo. We are having a civil discussion about the supposed benefits of keeping your Gen 3's EGR circuit cleaned out and like new.

 

I recently cleaned out my EGR cooler and pipe (again). There wasn't much buildup after 20k miles on the pipe, maybe still good 80+% flow. I also changed the spark plugs, car has 115k miles now.

The car runs much smoother, starts nicely without any hesitation/roughness. Like a new car!!

Total amount I spent was 3 cans of brake cleaner ($6), coolant ($15) and spark plugs ($25). So it was a worthwhile maintenance.

I'll tackle the Intake Manifold and ports when the car gets close to 150k miles. I'll probably do a piston soak at the same time to help with the oil burning.

 

All good news, what about oil catch can? I’ll get mine done soon also.

 

No OCC for me, I'm predicting the car will perform well to 150k miles without an OCC, it should be able to do another 100k without issues once I clean out the Intake Manifold and change the PCV. By then I would surpass the 15 year mark and I should be moving onto another vehicle.

 

I agree with Bill. There really is no way the EGR being clogged should cause a failed head gasket.

No one has ever been able to explain how or why it would cause a head gasket failure.

 

Yep, nobody can explain it. Maybe you can ask those guys at Toyota that will sell you a service for $3000 when the gasket fails. Hopefully they'll give you a hint on where the problem lies

 

The local yocals won't know. They know how to repair it.
Maybe Corporate knows why head gaskets fail.
Maybe it's the weak link in this particular engine design.

 

That's an understatement!

I just know when I first cleaned the EGR pipe, it was more than 50% clogged at nearly 100k miles. Some of the pictures I've seen show that pipe completely clogged. Whether or not that causes the head gasket failures, it surely wasn't designed to be clogged. So cleaning it and the entire EGR circuit would bring it back to how the car was originally sold.

 

No one can explain why head gaskets go? I thought this was common knowledge.

Pixel XL ?

 

Number one cause of head gasket failure indicated as overheating, here:

5 problems related to head gasket failure (and how to prevent them) | Haynes Publishing

And pretty much the first sentence in this Wiki EGR article, mentions EGR's role in reducing engine cylinder temperatures:

Exhaust gas recirculation - Wikipedia

 

Bingo

Pixel XL ?

 

Are you saying there's even more DATA why cleaning intake manifold and EGR circuit will help gen 3 prius?!?!?!?!?!

 

EGR valve: problems, symptoms, testing, replacement

It even covers the turd gen prius' egr in this article.

 

That's great info on EGR function. It covers everything we've seen for benefits when it comes to the Prius. Better idle and less rough starts.

It mentions nothing about saving s head gasket.

The minor temperature increase should have zero impact on a head gasket.

There's no evidence showing a dirty EGR system causes head gasket faulures on ANY vehicle.

I'm going to clean mine, but I snapped the head off of one of the bolts so until I get a replacement for that it's staying in place.

 

Overheating the block and head with the coolant or water pump not doing its job is BAD, mkay?...


Now, what exactly is 'cylinder temperatures'? The actual cylinder walls? The actual momentary combustion event temp? The resulting EGT leaving through the exhaust ports?

As I keep saying, the O² sensors assures that the A/F ratio is working correctly, and the car is 'clean',,
with or without the EGR mixed in.
Keep reading on how EGR is there for minute increase in efficiency and emission control.

Now explain how a lot of cars (most?) have NO EGR system.
And how, on those cars that do sport an EGR system keep running even though their circuit is obviously getting choked down with each tank full.

Gents, I understand there is a visceral feeling of accomplishment after spending hours cleaning out the poop pipes on your Gen 3. If I liked working on cars I'd enjoy that feeling also!

Gents, you have your WAT*. Keep after your Preventative Maintenance schedule.
Those of you that take your Gen 3's into the +300k territory report back about your Head Gasket health.

Me, I'll stay on this side of the fence and leave those dirty pipes alone, and wait for a performance problem or a fault code to tell me there is a problem.

My WAT is some Gen 3's go through life never seeing Full Throttle, or maybe see it for 5 sec once a year.
Some drivers use that silly display to limit their power to save a 'buck-a-week', and become an obstacle.

I take FAST road trips. 85 MPH into crazy crosswinds resulting in 31 mpg displayed for a couple tank fulls.
(This happened once...Normally it gets great MPG and the return trip was normal!)
My WAT is that is clearing the poop pipes a little bit.
But, without taking the EGR system apart after a road trip to confirm this, it's just a WAT. No data.

*Wild Azz Theory

 

Ummm,
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So, kind of an opinion piece. Can you post something from the SAE or other reputable sources?
It talks about 'prolonged detonation'. That doesn't happen on modern engines.

But, thanks for this:
The Toyota bulletin T-SB-0027-16 for 2010-2012 Prius models describes a vibration and tapping noise at a cold start that can be caused by a sticking EGR valve due to carbon buildup. The repair includes reprogramming the engine ECU, replacing the EGR valve and modifying the wiring harness.

What about this TSB?
Do we all need it performed?
edit: found it. It's if you have cold start rattles due to a stuck open EGR valve.