My Major Surgery saga on my 2013 Prius V.

This all started on another thread in the Reular Gen 3 Prius Forum:
Techstream EGR Valve Blockage Data

I began this Odyssey in post #90, which I have pasted here:

OK, I am an Uber Driver in Philadelphia, and I am driving a 2013 Prius V two with about 95k miles on it. When I bought the car at 22K miles in 2017, I thought the oil change interval was 5K miles. During the entire time I have owned it, I have changed the oil every time the "Maint Reqd" light came on. The car does not burn oil (yet). I have plans to do a full EGR + Cooler + Intake Cleaning (Which I call "the major surgery") next week (end of June 2021).

In order to further this project that ChapmanF proposed above, I wanted to get 5 readings of the "EGR FLOW INSUFFICIENCY" before performing the "major surgery". As will be shown, the value that is reported for EGR flow does vary depending on the conditions when the test was performed.

The EGR FLOW INSUFFICIENCY is part of the "Emissions Monitors" required by our government. ChapmanF suggested that one can read an EGR flow, then "Clear All Monitors" to set the "EGR FLOW INSUFFICIENCY" to zero. "Clear All Monitors" is the same function one would use in any ODBII app (Phone of PC) to "Clear the codes", and turn off the Czech Engine Light. That way, you can drive some more, and if you check again and see a non-zero value, you know that value is newer than the last data point you recorded.

Over the past few days, I have been carrying my laptop under the seat with me while I Uber. Whenever I took a break, I used a phone app to see if the EGR Monitor was marked as "Complete" (I.E. a new value is available). If the EGR monitor is still Incomplete, there was no reason to pull out my laptop. If it was complete, then I fired up TS and took a screenshot of the new value. I also saved the .TSE files, but I don't know if they add any value to this project.

As of last night, I have acquired 5 values:
- EGR-2013PRIUSV-094.290.miles-PreClean: 14.76 kPa
- EGR-2013PRIUSV-094.362.miles-PreClean: 15.09 kPa
- EGR-2013PRIUSV-094.432.miles-PreClean: 14.90 kPa
- EGR-2013PRIUSV-094.507.miles-PreClean: 15.60 kPa
- EGR-2013PRIUSV-094.569.miles-PreClean: 15.41 kPa

Average: 15.16 kPa; 1 Standard Deviation is .35 (+/- 2%)

Note that the weather during all five data points was the same. Temperatures were between 70 and 85 degrees F, dewpoint was in the range of 60-65 degrees F. The last three data points were on the same night. The last two points were dominated by a highway drive of 20+ miles at 60+ mph. Both involved going over a bridge over a major river, so there was hard acceleration on the upstroke, and coasting on the downstroke of the bridge (at highway speed). I am curious if any of that explains the slightly higher numbers.

Stay tuned for photos of the "Major Surgery" that will start on Monday.

 

Some Pics from Monday:

Hood open, have not started yet:

Hood Open: Wiper Shelf and Air intake gone:

More to come later...

 

So far... moderately clogged arteries. Can just barely see light through the original cooler. The difference between the eBay cooler, and the original cooler is amazing. Probably could have gone another 20-30k without a meltdown, but not much further. The plugs came out as looking worn, and no trace of oil fouling. Replaced. Coolant is not brown like I thought, but not bright pink either. I could not get the Phillips screws off the EGR valve itself, so I will clean it up as best I can.

I started on Monday, the first day of 95+ degree hot humid weather. If the heat wave breaks tonight, it will be rain. I need this car to Uber this weekend, as the 2017 isn't registered in PA yet. I have already decided to do the Intake manifold and Trans fluid a few weeks from now. A thorough cleaning of the EGR might be part of that job.

If I get pouring rain for the rest of the week, I might get the 2017 registered, but then my wife and daughter would car-less. Also the 6% sales tax has me wanting to put off registering until July 13th, when the 30 day tag expires.

Right now (3pm) is the best shade of the day on my driveway. I will post some more pics after dark.

 

Ok it is Thursday Morning... I'll try to keep the photos coming in chrono order.

Monday Afternoon: Plug replacement shows worn plugs no oil fouling!


Here is the EGR Tube with Flashlight shown through:



EGRTube with light:



EGR while still on engine:



Exhaust Flange where Cooler Attaches:


EGR Cooler from EGR side:



EGR Cooler from Exhaust side:


EGR Cooler with Flashlight shown through:


Clean Ebay Cooler, with Flashlight shown through:



Short Elbow on EGR:



EGR Valve Cooler side:



Other end:



Could not Get EGR apart, attempted to grind off Phillips Heads:


Cleaning Attempt of EGR using Purple Power:



New vs. Old Coolant at 94k:



Thanks to someone on another thread that suggested disconnecting the hose going to the radiator in the exhaust pipe! Disconnecting hose there really drains a lot, and is not covered by engine bottom panel. Given the slight slope of my driveway, and the car jacked up, this is the lowest point in the cooling system.

I also blew air (by mouth) through some open cooling hoses. Additionally, disconnected the resevior to drain it as well.I think I got at least 80% of the old coolant out.

Also, the tool gods demanded a sacrifice: My only 3 inch 3/8 extender and a six sided half inch socket are lost behind the transmission ):. I did manage to retrieve my 12mm flex end ratcheting box end wrench .

The clean eBay cooler and EGR are now installed, but hoses are not attached. It got too dark, and I forgot to photo.

Wish me luck, we are supposed to get a thunderstorm this afternoon.

 

I intend to do the intake manifold + Transmission Fluid + Inverter Coolant as a separate project later this month. All three can be done without removing the windshield wiper shelf.

 

I could use some help. I spent an hour re-connecting the cooling hoses to the cooler. Now I can't find the unrelated hose that kept getting in my way. I had my hand on it when I first started re-connecting hoses, and I pushed it out of the way. I suspect I was so angry at it getting in the way, I pushed out of sight.

I am embarrassed to say spent 20 minutes looking for it, but now it is raining. Below is a crop from the "Before" photo showing the hose that I now cannot find. It is the one with the blue mark, and no hose clamp, between the cylinder head and the EGR stepper motor. If I knew where the other end of the hose went, I could start working backwards from there.

The metal tube goes towards the firewall, where it connects to a hose with a clamp, that goes down alongside what I think is the brake master cylinder, or a related part that takes brake fluid. It may go all the way down to the transmission.

 

I had the EGR out of the car, and I know I have one of those hammer impact wrenches someplace (I found the bit though). Even if I had that Impact part, there isn't enough clearance to use it.

So I borrowed my neighbors hand held grinder, to take the heads of the screws off. Didn't seem to work. You can see the flattened heads of the screws in the photo. I bought a $10 screw extractor set to finish the job. Instead of using the extractor set, I just decided to see how good a 20 minute soak in Purple Power, and some wire brushes would do. Not quite as clean as taking the motor off, but a lot better than it was.

When I do the job again in 75k miles, I will plan my time so I can use the screw extractors, or spend $75 on an eBay EGR.

 

That would explain the lack of a hose clamp. It has stopped raining, I'll take a look. This hose has gotten in my way a lot of the time during this project, so it is doubly embarrassing to lose track of it.

 

THANKS!!! The Evap system and looking for a Solenoid was the key to finding the hose. There is something that looks like a Solenoid mounted below the intake manifold near where I would expect the hose to come from. One end has a hose going directly into the throttle body, and the hose on the other end goes under the inverter...

Wait, why would the Inverter need manifold vacuum? I pulled on the hose coming from under the inverter, and there was my missing hose end I feel silly, but I have been so focused on the EGR system, that any else became irrelevant.

I guess the tool gods were after revenge. I took back my 12mm ratcheting box end wrench, and they only got to keep my 1/2 inch socket and 3 inch extender.

 

Great photo. You keep your engine so clean. I think my valve is a little different than yours, but does the same thing.

 

NEXT STEPS:

1) Reassemble air intake system. This time I will remember to plug in the Air Flow sensor. When I changed the plugs on Monday, I thought 'what the hey, I'll start the car as a sanity check that everything still works. It is amazing how many error codes result from a disconnected Air Flow Sensor! One of them was a proprietary code about the Traction battery being bad. Go figure.

2) Refill the coolant, check for leaks.

3) Reinstall the wiper shelf, ironically in the rain.