2010 EGR system clean-out

I’d stick with brake cleaner for the intake. There’s pressed-in threaded metal bits that react with oxi. If you rinse VERY well, and maybe apply a light oil to the threaded inserts it’ll be ok, but oxi is overkill anyway. Using oxi is fine on the cooler though; that’s where it’s most needed.

Both intake manifold and the full Exhaust Gas Recirculation circuit need doing. Do just either one and you still will have reduced Exhaust Gas Recirculation flow: the egr gasses flow through egr components and THEN through IM passages. With IM pay particular attention to the small diameter passages at each port, they deliver egr to the individual cylinders.

More info, links, Repair Manual excerpts:

Bad Flywheel | PriusChat

 

Get a back brace and set aside 4 hours for madness.

Also be ready to lose some skin.

Make sure you have the right tools.
Make sure you dont drop anything.

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Yes. In particular be ready to catch the rear EGR cooler gasket when you lift the cooler off. It’s good to raise the front and remove engine under panel: access from below is sometimes easier, and if anything drops you have an even chance it’ll make it through to the ground.

 

@Mendel

I actually dropped the egr pipe gasket that clips on if you can believe that.

Will be jacking the car up today to remove the panels and see if its there.

I ordered another one if anyway but it wont be available until Saturday.



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You really have to do the egr cooler, it is the first thing to clog. It is also the hardest thing to access and clean. There is so much work involved getting to that point, the intake manifold and the catch can are then easy. Realize there are several very difficult parts to see and disassemble. If it were me I would take a vacation day on a Friday when parts are more likely to be available. Then use Saturday as a backup.

Forums like this are not setup well to find any particular information and it is rarely detailed when you find it. A straight google search with priuschat as one on the words works best for me, but you still have to sort the wheat from the chaff.

 

I dropped the rear gasket, well more like I never even noticed it, in the excitement of finally pulling the #$@* cooler out. That one has NO clips. I only caught on when reassembling, realized there was no gasket. It had fallen about halfway down, landed on something. Luckily I spotted it and was able to fish out with magnet or grabber, forget which.

But yeah having the car slightly raised and engine underpanel off helps a lot. Except that it makes access from above a bit more of a reach.

@Mikethe3d maybe start by removing the nut on the underside bracket of the cooler. This can be done without any other disassembly. It's VERY tough to get to, will require pulling conduits out of the way as much as possible, and you need to experiment with various ratchets (swivel head good, and longish handle), extensions (various, 1.5" and 3" most likely to work), short-vs-long sockets. You're going by Braille mostly. It's just around 3 o'clock relative to a large diameter braid-sheathed coolant hose going into the head, as you face it. Watch the EGR cleaning video (in the link I posted above), take your time.

That's the hardest nut to extract. And you can leave it off, there's plenty more fasteners on it. I've also removed the stud that that nut goes onto, backed it right out of the head and left it off. That takes a Torx E8 socket if I recall correctly; this further facilitates extraction of the cooler, one less hindrance. That was very difficult, had to go very slow, was afraid I'd strip the head of it. It's not critical to that in advance, probably easier to do while cooler is off the car.

Again, do read through the tips and tricks, links and so far, in the link I posted up the page.

If you want to swing by I might be able to help, getting that nut off, and share a few tips. PM me if interested. I'm in North Coquitlam.

 

I had spares of all the gaskets ready just in case. Ended up using one or two.

 

Hi guys! I'm new to the Prius Chat. I came here looking for a way to be able to ask Mendel about any simple tests to check the EGR system for carbon before having to dismantle so much. I was not able to view his link on his information page to EGR cleaning, but that may have been because I was not signed up. I do have a 2011 Prius 4 with over 189,900 that has a slight shudder at low speed with the ECO mode on. I bought my Prius in February with about 185,000. This problem has only been since April and seems to vary depending on where I get gas. I have been using fuel system cleaners since then, have changed the plugs to NGK Ruthenium, changed the air filter, just changed my oil when the system notified me to a Castrol Edge synthetic 0W-20, and recently had the main coolant flushed and replaced. I noticed today that turning off the ECO mode stops the shudder problem with mild acceleration. I have seen the threads about this problem and the main comment seems to revolve around coolant getting into the cylinders. So far my new coolant level is stable, and the flushing system process proved that the coolant system was dirty even though the previous fluid did not seem that way. However, I went through a process of adding about a gallon of Peak Asian pink over a two week period, so I new something was wrong with the system.
My main question for Mendel is now should I use a stop leak in the coolant reservoir? And, I did purchase one new coil to use as a tester, but maybe I should have replaced all of the coils when I changed the plugs? I did get a coil tester that only proves that all of them are working, but not if there is any minor failures in them. I also am thinking about going to the trouble of flushing the Inverter coolant also mainly because I have no idea if that system is dirty also. Because turning off the ECO mode may be lightening some of the load on the electric motor I am thinking that its cooling system is faulty. However, as many of the posts about carbon in the EGR system seem to also mention the same acceleration problem I am experiencing then perhaps I too need to clean that system on my car. Hopefully, I can view the u tube video in Mendel's link to see how to pull at least the pipe he mentions to look for carbon!!! Anyway, thanks to all of you for providing so much practical information. I don't like being told at my local Toyota shop that I have to pay in excess of $64 just to have my engine codes read when Autozone does it for free!!!! Makes me want to do all of the work on my car myself. BTW my first car was a 57 Belair 4dr hardtop, lots of chrome, my Dad had the auto trans replaced with 3spd manual, manual brakes instead of power, 283 bored out to 300, I did the upholstery on the door panels, I did some of the paint change to a blue metallic enamel with my Dad's help, and even fixed a rust hole in a rear quarter panel with a metal disk and wire and bondo with lots of sanding!! Thanks also to Mendel for reading this!!

 

Mendel himself seems to rarely mention this, but measurement of EGR flow is a self-test built into the car itself. Any scan tool that can read "Mode 6 emission monitor results" can show you the last self-tested value, which you can compare to others on the exact thread we have here for that purpose.

Whenever you decide to do the work, it is also very valuable to post your own mileage and flow result from before you do the work, and then your new flow result after. That adds to the information the next person can use.

The flow test result is just one overall number for the whole engine. It cannot individually test the four separate EGR passages that are in the intake manifold. Those can cause unbalanced EGR delivery to the four cylinders, without showing up in the overall test result. So it is a good idea to now and then take just the manifold off (which is quite easy, compared to a full EGR overhaul) and visually check/clean those ports. You would especially do that if you have any feeling of engine roughness that is absent at idle and high loads (times when EGR isn't in use) but present at mid loads (when EGR is used). Symptoms like that would point pretty strongly at unbalanced EGR through the four manifold passages.

Assuming that any slight shudder at low speeds is a result of a failed head gasket and coolant in the cylinders is like assuming that every headache is a stroke. As just discussed above, that can often (if mid loads are the time you notice it) be a simple matter of cleaning manifold passages.

If there is coolant in the cylinders, there is a problem that has progressed beyond whatever initially caused it. Even if an EGR problem was initially at fault, fixing that problem at that point will not unblow the head gasket. It'll have to be replaced. (Or you could try stop leak, but there is little enthusiasm here for those products.)

But again, only apply stroke treatments if it's a stroke. Especially with the stop-leak products, you certainly don't want to pour those into an engine you're not even sure is leaking.

 

I wouldn’t. So far your engine coolant level is stable in the reservoir? Your miles are getting up, into the zone where head gaskets (quite reliably) start letting go.

see first link in my signature for EGR cleaning info. If on a phone turn it landscape to see links.