2011 IM+EGR Coolant Cleanup Saga - With updated details

I'll begin by adding my HUGE thanks to everyone who helped create the NutzAboutBolts videos. They are very VERY helpful!

As an experienced test engineer, I tend to take note whenever my reality doesn't match the documentation, and I record what I've found.

This thread will hopefully help any who are dealing with 2011 rather than other-year Prii... or perhaps what I see is just the normal variances seen due to timing and parts suppliers.

I *WILL* get to that. But first, some crucial lessons learned today as I disassembled my 2011 Prius under the hood for the first time. Pictures will also follow. I'm just tired and need to zzzz but wanted to write this up while memories are fresh...

COOLANT DRAINING

• No need to go under the car at all, other than to place a low/wide bucket under the left end of the radiator.
• As long as you're removing the intake manifold, once that's out of the way, look down and toward the driver's end of the bottom of the radiator.
• You'll see a yellow tabbed screw cap. Loosen it and coolant drains straight down into your already-placed bucket. (Much faster if the overflow tank cap is removed )j
• With a few quarts of coolant drained, the only pipe that released some coolant for me was the lower back EGR cooler pipe. I clamped it off to avoid a mess. AFAIK that's the only clamp needed if you drain some coolant first.

TOOLS

• Yes you need an E8 (Torx External/Socket)... but it MUST be a shortie E8! There is a total of barely over 2 inches of working room in back for the back studs to be removed.
• And it appears a shortie ratchet is also a necessity (unless there's a different solution I've not considered.)

DISCOVERIES

• As this was my first time opening it up (all prior work by dealer), imagine my surprise to find several cowl clips missing, and two of the nine cowl bolt heads broken off. No wonder it's been rattling.
• (Anyone have experience convincing a dealer to take care of bolts THEY broke off?)
• (I assume I get to do screw extraction and find some replacement/matching bolts)

 

Gaaaah! A friend took me to auto parts store to get the correct E8.
Within a minute of my return, it slipped off the torx pin and dropped into the bowels of the car
My only clues: it fell from the top pin behind the cooler... and I heard metallic noises in its final motions before all was silent.

Is it hopeless to go fishing with magnet-on-string?
Is there a simple way to access appropriate under-vehicle parts?
Do I just go get another E8?
And what about Naomi?



(That latter is a reference to an obscure kids' show on PBS )

 

Great pick-er-upper ideas. Thanks! I'm thinking I need a little webcam-on-a-stick to look around down there.

In any case... bought another e8, finished removing the final bits... oh boy does this poor car NEED some EGR cooler TLC!

Water simply does not flow through at all, it is so clogged. Cleanup on aisle 29 has begun..

 

Update to the OP tools section:

 

DISASSEMBLY and NOTES ON TWEAKS to NutzAboutBolts Videos

A starting point: clean but unhappy 2011 Prius Gen3



General Comments on sequence and timing of removals/cleaning:

• The EGR cooler takes much longer to clean than any other part. I wouldn't bother cleaning anything else until you've got the EGR cooler in its first round of whatever soaking is needed. There will be plenty of time for cleaning everything else.
• 2011 Prius III: there's only about 2 inches of headroom between the cowl and the top of the igniter/spark plug access. [H/T @ChapmanF: that's true for drive-on-the-right. Drive-on-the-left have a different wiper setup and smaller cowl!]
  • I waited until after the IM was removed to remove my cowl. Just curious about how far I could get while leaving it in place.
  • IM removal is easy without removing the cowl.
  • EGR/cooler removal? Fuggedaboutit. You must remove the cowl to get that done, at least in the USA... maybe on a lift? I don't happen to have one...

Cowl Removal (NAB Spark Plugs Remove and Install video)

• 3:45-4:50 Clip removal. A trick I learned and expanded on from comments in a video on HV battery removal: almost every clip of that type can be cleanly and easily released using a 10mm socket or equivalent if no room for a socket! (10mm ratchet wrench, combo wrench, etc.)

Intake Manifold Removal (NAB IM Cleaning video)

• 2:53 NAB lifts off the air intake after removing two 10mm bolts. Mine is not that simple: there's a wire bundle zip-tied to a post on the (driver-right) left end of the intake.

• (As @Mendel Leisk has noted, there's no need to disconnect the coolant hoses to the throttle body. It easily moves out of the way for removing the IM and/or EGR/Cooler.)
• 9:10 there's a bolt with a wire bundle right next to the head. I couldn't even fit a 10mm combination wrench in there, but a box wrench was fine.

• 10:50 on mine, the EGR pipe metal gasket has strong spring clips holding it in place. Only a small amount of care is needed to avoid dropping it.
  (Note from EGR Pipe Cleaning video, 9:10 -- the gasket actually clips to the EGR, not the EGR pipe! So please ignore that the gasket is attached to the pipe here)

• 12:11 the clip under the large cable bundle is tricky to release. It's actually squeezed from the sides, underneath, accessible with a screwdriver or two from the windshield side of the engine.

• 12:15 several clips are squeezed from the back side. (As described above, use the same 10mm socket/ratchet/combo wrench trick to easily remove.)

• My Intake Manifold looks pretty bad. Is that a blob of junk just sitting there? Yeesh.

NAB EGR / EGR Cooler video

• With the IM removed, the coolant drain is easily visible from above. Time to remove a few quarts of coolant before we continue.

• 1:00 I don't need to clamp the coolant hoses. Saves a bunch of hassle and mess. Thanks, @Mendel Leisk!
• 6:20 and 12:40 There's a metal gasket between the EGR Cooler and the Exhaust Manifold. Fortunately, there's enough visible, I was able to use some duct tape to hold it in place, thus avoiding any concerns about loosing it while removing the EGR cooler.

Result of Disassembly: My EGR Cooler has NO flow at all!

I am soooo glad to be doing this procedure. My EGR cooler was 100% clogged. I could pour water in one end and let it sit for an hour with no leakage.

Cleaning steps so far (about 15 hours so far including an overnight pause):

• Initial hot water rinse
• OxiClean for a short while, mostly to get the bulk surface gunk off
• Power wash with low pressure (wobbler) spray. What a mess!
• Several OxiClean soak-until-no-more-bubbles at each end. (Result: both ends look nice and shiny, and a few carbon chips came out, but still no water would go through!)
  
  
• Power wash again. More gunk out.
• Power wash with a 0 degree needle spray. Suddenly, water's coming out the other end! Water at the end of the tunnel so to speak.
• (Current) Realizing I want all channels open, I took a two quart pyrex measuring bowl, dunked one half of the cooler in it, mixed up oxiclean and poured in until the bowl was full. I'll let that soak, then flip and do the other end. This might not be enough to get the center but it should come close.
  (Meanwhile, I'll hunt down some good stoppers, and a spare bicycle tire spoke, and see if I can soak the entire insides.

 

Looks like the 2 quart OxiClean bath loosened it up enough so that a needle power wash spray could cut through. Results ASAP.

I'm about to go out and collect the gaskets, PCV valve, etc ordered at the dealership. May do plugs while I have it open. It was 70k miles ago at 130k... hmmm

 

Oh, a key question: I blasted the EGR itself with water. Was that a horrific thing to do?