Finally replaced EGR valve/cooler today

223667 miles - Prius has been running great but I knew it was going to be needed. Back in August I picked up a EGR valve+cooler from ebay for $100. Got all the gaskets for the EGR cooler to the IM from the local dealer, along with another gal of coolant. (I still had about 1/2 gal remaining from the last coolant change) Picked up a e8 torx socket from the local auto parts store.
Started at 9am this morning. Finished at 7pm this evening. Prius started right up with no codes/errors/leaks!

I have not installed the wiper tray yet as I want to change the spark plugs & install a oil catch can, both of which I already have.

The EGR pipe was lined with an oily carbon coating but it was not plugged. The IM EGR passages were likewise quite nasty but they were not plugged completely. Actually the EGR ports at each cylinder were fairly open. Everything on the IM was nasty though. I used a strong solution oxy-clean & various bottle brushes from Harbor Freight to clean the EGR passages in the IM.

The EGR cooler looks almost fully plugged looking at it from the exhaust manifold end. I'm guessing there is still some airflow there, otherwise all the rest of the EGR plumbing would be plugged up. Not sure though, I have not separated the cooler & valve yet.

This is the first time I have opened up anything on the Prius engine. I do keep a close watch on the fuel mileage & have not seen any change - I was still getting >50 mpg on most tanks around town.
I knew the EGR cooler was going to plug up eventually & I did not want that to lead to a blown head gasket. That was probably my biggest incentive for getting this done now

& a big Thank You to --->NutzAboutBolts<--- for the fine job on all the vids!

 

Yes I did have to clean the ebay EGR valve & cooler. The parts came from a low mileage vehicle. I separated the valve from the cooler & used purple power on the cooler. A few soaks at full strength & it was getting spotless. I found a rubber stopper at Lowes that fit the exhaust manifold end perfectly. Hillman brand "rubber stopper" #4
With the stopper in one end I would fill the cooler with purple power & let it soak overnight. Like magic it became spotless!

The EGR valve I was a little more careful with. I think I used carb cleaner mostly & a wire brush. I did remove the black end (two screws) & I manually opened the valve while I was cleaning.

 

This was removing & cleaning the Intake Manifold also.

Actually it took right at 5 hours to get everything disassembled. Then another 1-1.5 hours to clean the IM, then about 3.5 hours to get it all back together (except for the wiper tray).

I'll admit, its not as much fun as it was many years ago!

 

UPDATE: after separating the EGR cooler from the EGR valve I find that the cooler _was_ indeed fully plugged with carbon. After cleaning the carbon off of the exhaust manifold flange end I could not blow through the cooler at all!

I put a cork in the exhaust manifold end & poured Purple Power into the valve end & am letting it soak overnight. I can see the Purple Power does dissolve the carbon but it is going to take a long bath to get all the carbon out. I went through about 2/3 gal of the Purple Power cleaning the ebay cooler & it came out spotless inside & out. Using the cork I can fill up just the cooler & let it soak, then change the cleaner lots of times.
I'll have to pick up another gal of Purple Power to finish cleaning this cooler.

The only slight indication that something might have been astray was my fuel mileage had dropped slightly, say from 55mpg down to ~50mpg driving on surface streets around town 35-50mph in stop & go traffic, also running the AC 100%, so I wasn't sure if I had a problem.