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2010- 3x EGR Valves, Preventive Maintenance

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Prius_Angie, Jul 24, 2020.

  1. Prius_Angie

    Prius_Angie Active Member

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    The Gen4 engine bay looks tighter & still have a windshield wiper cowel! grrrr. (n)Can you get to the spark plugs w/o removing the cowel?
    Seems they angle fitted the throttle body? Is that EGR circuit in same place like Gen3, but w bigger black plastic valve cap?
    Nice new Oil Catch Can!
     
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  2. Raytheeagle

    Raytheeagle Senior Member

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    It is more crowded, given they put the 12 volt up front now:cool:.

    Now the inverter is centimeters away from the egr cooler, so the inverter will have to be shifted out of the way to perform a circuit cleanse:(.

    But once I get to 120k miles, I'll see what I find;).

    At 70% EV though, the actual mileage on the engine will be very low:).

    So hoping to find piece of mind and not a 50k service interval(y).
     
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  3. Prius_Angie

    Prius_Angie Active Member

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    Ok, i just got back from Home Depot to complete the project. They are so much BETTER now w the 2x new hex bolts (M5 16 mm long) & 2x lock washers: access, tight fastening w lock washers; ease of bolt head removal; durable zinc coating, prettier, etc.
    Much thanks all!
    P_20200726_124206.jpg P_20200726_164044.jpg P_20200726_164058.jpg P_20200726_124137.jpg P_20200726_124200.jpg P_20200726_124214.jpg P_20200726_124307.jpg P_20200726_124331.jpg P_20200726_124318.jpg
     
  4. Prius_Angie

    Prius_Angie Active Member

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    With that OCC you placed in your car, you will be well better off than peers in regards to clogged EGR circuits. Any notable evidence of oil blow by? I have a good feeling about your 4thGen.
     
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  5. Raytheeagle

    Raytheeagle Senior Member

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    I've put 3k miles on the Prime since then install;).

    And I've collected about a teaspoon worth of spooge in the can so far:).

    So it is working. I'll take a pic tomorrow for show and tell (y).
     
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  6. Prius_Angie

    Prius_Angie Active Member

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    thats a great sign that the OCC is doing what its supposed to do :)
    :eek: but its a bad sign for the 4thGen design--- bad hereditary genes passed from 3rdGen to 4thGen
    this will never end; imagine 5thGen...
     
  7. Raytheeagle

    Raytheeagle Senior Member

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    Meh, every engine has blow by;).

    Since the PCV valve dumps the crankcase pressure back, it'll have some carryover:whistle:.

    The key is to catch it before it gets to the intake:).

    So we'll see if this helps since I had 21k miles on the prime at install(y).
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Thank you SO much; that is gold info!

    I previously guessed at the 5mm diameter, by reaching around, pressing a finger tip against the the end of the screw, then measuring the indentation on my finger lol.

    M5-0.8x16
     
  9. Prius_Angie

    Prius_Angie Active Member

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    best video I've seen on problem identification and cleaning
     
  10. ChapmanF

    ChapmanF Senior Member

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    12:51 "Cortland has finished cleaning this up and lubricating it".

    I wish he had explained what Cortland used to lubricate it. I'd want it to be something that'll stay lubricant at the temperatures of an EGR valve.

    He did three separate things there: (1) he fixed an EGR valve that was stuck open, (2) he cleaned an EGR cooler that was kind of obstructed (but we don't know how much its flow was reduced, other than how it looked), and (3) cleaned out the EGR passages in the intake manifold.

    Since the first test done by the mechanic was to block EGR completely with a plate, and the misfire went away, we can conclude that for this car the misfire was caused, at least in part, by the EGR valve not closing. Cleaning the cooler was a fine thing to do, but this car wasn't really having a too-little-EGR problem. Indeed, we know the cooler was flowing enough gas to cause misfires when the stuck-open valve wasn't blocked off.

    I got the impression the problem wasn't really solved until the differential obstruction of the intake manifold EGR passages got taken care of.
     
  11. wheezyglider

    wheezyglider Active Member

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    With nothing good on TV tonight that was worth a watch! :) Instructive use of a scantool - he explained how he was looking for evidence of an ignition coil issue and how there wasn't anything different between cylinder 1 and the others. But the trick of blocking the EGR with a shim was especially cool, more definitive than disconnecting the valve electrically especially in case of a stuck-open valve. [But hey wait - even with a shimmed off valve there's no P0401 EGR Insufficient Flow? Why am I not shocked.]
     
  12. ASRDogman

    ASRDogman Senior Member

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    Nifty..... If he had read Prius chat, he would have know what the problem was. :)
    It would have been nice if he showed talking the valve out and how to remove the spring.
    I don't know what he "lubed" it with but I'm sure it won't last. Hopefully it won't clog it up and it sticks again.

    He certainly didn't clean the cooler good enough. Maybe he doesn't have a pressure washer? :)
    Or after he cleared it out it soaked it in the parts washer....

    It was one of the better videos... Thanks for posting it.

    I wonder if he'll replace the spark plugs anytime soon????
     
    #32 ASRDogman, Mar 16, 2021
    Last edited: Mar 16, 2021
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  13. PriusII&C

    PriusII&C Active Member

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    Regarding the lube for the valve stem, I wonder if brake caliper pin grease work?
     
  14. ASRDogman

    ASRDogman Senior Member

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    That would be a good guess. But it's bronse guide, so it doesn't need any lube.
    Like the valves in the engine head.
    But with exhaust gases going over it, it gets a lot hotter than brakes, and it will probably
    harden it up and attract the carbon, causing it to lock up.
    Considering how long they last, and cost, it wouldn't hurt to try. And if you are cleaning it yourself,
    that's labor cost you aren't paying, just some time.

     
  15. ChapmanF

    ChapmanF Senior Member

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    The ECM isn't able to continuously monitor for that. The test it uses is to open the EGR valve some during a time when you are decelerating with the fuel cut off, and look at how much the intake manifold pressure changes according to the MAP sensor. It has to wait for those fuel-off deceleration opportunities to sneak that test in, and they don't always come around that often, especially in a Prius, which might just turn the engine off in many of the situations where some other car would be in decel fuel cut.

    You can always pull up the result from the last time it did that:

    [​IMG]

    If you have just now shimmed the valve off, one thing you can do is a code clear with a scan tool (even if there aren't any codes, that still also clears memorized test results, so they will be reported as 'incomplete' until the car has its next chance to collect them), and then drive the "confirmation driving pattern" that is in the repair manual for P0401. That confirmation pattern includes some deliberate fuel-cut deceleration in inspection mode, to make sure the ECM gets a chance to perform the test.

    After that, you can pull up the test result and know it is a current result obtained after you cleared the memory. If we were making book, I'd give odds you'd see a P0401 at that time.

    Needless to say, the same procedure (clear the test memory, then do the confirmation drive) is one you can do any time you want, without shimming off the valve, if you are simply interested in its current flow condition and want a known current result to look at.
     
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  16. wheezyglider

    wheezyglider Active Member

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    Fair point, without intentionally driving a fuel-cut pattern he might not have triggered the EGR flow self-test on a short drive. In fact, when he was doing that early morning test drive, and not being "a Prius guy", I wondered if he got far enough past S4 warm-up to even allow for EGR operation to begin with. From playing with Torque, it takes surprisingly long for a cold engine to get there in city driving. So the one thing I'd change in his approach is to add a graph of Commanded EGR % to the scantool along with the Misfires Detected just to prove that the valve is trying to operate. (OK with the valve shimmed that's moot, but a guy this admirably thorough would want to know for the final shakedown.)

    BTW I remember checking that flow test result after cleaning the EGR stuff on both our 2010 and 2012. From memory, two things struck me: the manual didn't say what a "normal" value was; and the fully OCD-level cleaned results between our two cars were wildly different for no clear reason.

    I remember that someone had a thread about tracking that test result to assess EGR cloggage. If my Techstream setup was easier to work with I'd be monitoring that every oil change. But I lose hair whenever I touch Techstream. (I envy the snap-on scantool that guy used.) Too bad we can't get that test result through Dr. Prius app or something over OBD2.
     
  17. StarCaller

    StarCaller Senior Member

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    that's what I was wondering, is a lower or higher number better (meaning less clogged) ?
    my number was quite lower than ChapmanF's /

    [​IMG]
     

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  18. ChapmanF

    ChapmanF Senior Member

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    High numbers good, low numbers bad. You can divide by the test minimum (0.8 kPa here) and say "well, tested out about five times the minimum to pass". When a computer geek looks at that max "655.35", that's as good as a flashing sign saying "max doesn't matter for this test".

    There is a lot of normal variation, I think because the ECM squeezes the test procedure into whatever fuel-cut decel opportunities it happens to get, and there's variation between those. Mine measured 10.something in the photo I posted here, but has also measured 17.something since then, with no work being done.

    The more data we accumulate, the more we will know about what the normal variability is and how strongly different values suggest trouble. That's just math, once there's enough data to math with.
     
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  19. ChapmanF

    ChapmanF Senior Member

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    That was meeee! Here's the thread.

    I think it might be a standardized OBD function to retrieve monitor test details. Somebody else recently posted what the same details look like on their non-Techstream scan tool.

    Theirs reported the values in psi rather than kPa, but that's just an easy conversion. For comparison to the min value, I would convert the test value to kPa and divide by what Techstream says the min is, rather than dividing psi by what the other tool shows for the min value in psi, just because of rounding error, as I explained in that thread.