Cleaning the EGR cooler. Or Not!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Boffin, Mar 11, 2020.

  1. Boffin

    Boffin Member

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    My 2010 had 132,000 miles on it, and after reading the many threads on this site about how a carboned up EGR system can blow your head gasket, I decided that it was high time to clean it. This despite my very real fear that 10 year old bolts that have lived out in the elements for their entire existence have a nasty habit of beheading themselves rather than coming out of the threads where they lived.

    I watched NutzAboutBolts's excellent videos a few time, bought the necessary tools (not many of us have a female 8mm Torx socket tucked away in our tool boxes) and went to work. Initially, I was tempted to head on down to Harbor Freight and buy a high torque impact wrench, but instead, I just removed the bolts the old fashioned way, with sockets, extension, and a bit of swearing at how Toyota managed to hide critical bolts under a mess of hoses and cables. Once loose, my cheap B&D drill, with it's 3/8" attachment managed to buzz the bolts out. EasyPeasy.

    Imagine my surprise when I looked into the pipe and found only a light coating of carbon in it. I had expected to see a much heavier coating (again, see the NutzAboutBolts video). I suspect that this is due to my driving style. I almost always drive for over 10 minutes at at time, and often for an hour or more. Several time a year, I drive for 10+ hours. I think that the "Italian tune up" way of driving is what kept the carbon down.

    I cleaned the pipe with a saturated solution of OxiClean and hot water. First I soaked the pipe in the solution for about half an hour, and then forced a thin rag, soaked in the OxiClean solution, up the pipe with a screwdriver. After a couple of scrubbings from each end, the rag came out clean.

    Then I anti sized all of the bolts (They will be easy to get out next time, and there will be a next time!) and put everything back together.

    Note that when guys like NutzAboutBolts, ChrisFix, and Scotty Kilmer give you the impression that these jobs can be done in the time it takes to watch a short YouTube video, they're lying. They know precisely what needs to happen. The order things need to happen in, what tools to use, and how to get at the bolt or other part to get it out. You and I don't. We have to stand around and figure out what to do at each step, and sometimes back off and redo steps. What took NutzAboutBolts 17 minutes took me 2 hours. And yes, this was a fairly straightforward job. Still it's worth it. You'll not only know the job was done right, but you'll know how to do it again in the future. It will go faster then.

    I attach a couple of photos, one of the engine bay in general, the other shows the holes occupied by 3 of the 6 bolts required to pull the air filter box. These weren't immediately apparent in the video.
     

    Attached Files:

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  2. bisco

    bisco cookie crumbler

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    Yeah, it would be nice to know why some clog and some don’t.
    Then we could advise more effectively
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    So far you've just done the pipe, the one between EGR valve and intake?

    Also, resorting to oxi-clean soaks for that is a little overkill. A little brake cleaner and a bottle brush is all it takes.

    Trust me: if you clean the intake manifold, and the EGR valve and cooler, you won't regret it.
     
  4. Grit

    Grit Senior Member

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    My opinion when it comes to minimal clogging with high mile vehicles prius are when they are driven with ICE is running most of the time so tempature stays around 190F
     
  5. Pdaddy

    Pdaddy Member

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    My egr cooker is caked as pictured prior to attempting cleaning. I have been soaking in carb cleaner but does not seem to be getting out the thick deep stuff. What is the risk for putting this back on with blockage? 20200403_184916.jpg

    SM-G960U ?
     
  6. Ed Beaty

    Ed Beaty Active Member

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    "What is the risk for putting this back on with blockage?"

    Don't put it back in like that. Get some heavy duty oven cleaner, plug up the end opposite the one in your picture, shoot some in and let it foam for an hour, unplug and rinse. Repeat as necessary. Carb cleaner will not do the job. You may even have to poke the cooler openings with a piece of copper wire or similar, but oven cleaner should do the job. DON'T put it back in like this. Why go to all that work just to accomplish nothing?
     
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  7. Grit

    Grit Senior Member

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    We once cleaned 3 egr coolers within 15 minutes with a high pressure washer, but consensus here is to use chemicals that will take round of soaking & couple of days to get it half cleaned :LOL:
     
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  8. Raytheeagle

    Raytheeagle Senior Member

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    Use a pressure washer:).

    Go to the manual car wash places if you don't own one;).

    You've done the hard work, don't reassemble until the hardest part of the job is done(y).
     
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Just a vote for Oxi-Clean, as strong and hot as you can mix it, and let it soak an hour. Then rinse and repeat.

    That's just one approach, and when severly clogged, you probably need all the aforementioned as well. I'm not a chauvinist about this, try 'em all.

    upload_2020-4-4_10-14-0.png
     
  10. Pdaddy

    Pdaddy Member

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    Thanks everyone. I have alternated between carb cleaner and oxy and letting it soak in both (one night in each) overnight but only get a dribble coming through. Soaking in carb cleaner now. I will soak again overnight with oxy and may go to the self car wash tomorrow to use their pressure washer since I dont have one.

    SM-G960U ?
     
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  11. Pdaddy

    Pdaddy Member

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    By the way I have 220,000 on my 2010 and this is the first egr cleaning. Just changed the plugs with 100,000 on them and they looked decent. The air intake manifold had a bit of build up and there was a bit of oil pooled up in the throttle body.

    SM-G960U ?
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    Have you tried working a wire through?
     
  13. Borninblue

    Borninblue Active Member

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    Consider yourself very lucky. Your car could have went through two head gaskets by now.
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Funny thing, probably no warning lights. As far as Toyota and the dealerships are concerned: nothing wrong.
     
  15. Borninblue

    Borninblue Active Member

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    What about your water pump, original as well?
     
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  16. Grit

    Grit Senior Member

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    Or maybe car never gets driven hard and is babied on the road.
     
  17. Borninblue

    Borninblue Active Member

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    Either way it would be the EXCEPTION rather than the rule. Just by the posts on this site it is quantifiable.
     
  18. Pdaddy

    Pdaddy Member

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    Yes originol. When that goes out it will be just like in an older gas car? Easy to determine with warning light without damage to the engine?

    SM-G960U ?
     
  19. Raytheeagle

    Raytheeagle Senior Member

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    The engine gets warm and hot coolant isn't good for anything ;).

    I proactively replaced the water pump in our old 2010, and helped a couple of others do the same thing:).

    They seem to have resistance if the impeller to freely roll over time:cool:.

    Best to tackle it before it finds you(y).
     
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  20. Pdaddy

    Pdaddy Member

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    So how much flow should be coming though the egr cooler? Since mine was about closed off to start with I now have a good trickle going through after cleaning and powerwashing. Should water be pouring through all the holes pretty prodigiously?

    SM-G960U ?
     
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