Was thinking about all the problems the EGR system causes in these cars and (without taking the time to check) I wondered if there was ever any indication that cleaning the cooler and intake manifold was ever something Toyota recommended? Was this system supposed to be maintenance free? Only asking because I learned about it on Priuschat and have talked to owners that look at me like I am crazy, meanwhile their cars are ticking time bombs.
If the EGR system is not working correctly, the ECU will trigger trouble codes P0401 or P0403. What will not be detected is if there is reduced flow or a blockage in one or more of the four small EGR passageways that are in the intake manifold. If this occurs, you will have uneven EGR flow into the four cylinders on the engine.
My newly acquired Prius couldn’t pass cleaning solution through the cooler and the intake ports looked completely gunked. I guess asking why it doesn’t become a maintenance item or is there more to Toyota admitting there is an issue? may be similar to my Honda Odyssey that has the VCM that shuts down cylinders to get about 1mpg better that the standard engine. It’s known to be so detrimental that there is several suppliers of products and trick the motor into never shutting down the cylinders to preserve engine life and motor mounts. Honda will never tell people to disable that nor do they provide any guidance
Toyota may or may not have know it was going to be an issue. Remember, car manufacturers really only care about the car making it to the end of the warranty. Then you buy another car. Usually these issue start showing up after after 100,000 and more miles. EVERY car needs maintainence. Everyone manufaturer has a vehicle that has not met there standard.
On Gen3, equipped with the EGR system, a greater number of errors are possible in the event of a malfunction of the gas recirculation. These include misfires, engine failure to start, and other errors.
There’s no maintenance of egr cleaning from Toyota, if so many people would avoid this vehicle. And ignorance is blissful to those crazy owners.
Besides reduced EGR flow, and unbalanced EGR flow, I would think once the EGR cooler’s internal radiator has any degree of carbon coating, there will an increase in the temperature of the recirculated exhaust gas. Toyotas stance on 3rd Gen EGR shortcomings is radio silence. Their warranty extension on the issue has the following phrase, and in their document they make it bold and underlined: “While the majority of vehicles will not experience this condition” https://static.nhtsa.gov/odi/tsbs/2016/MC-10134089-9999.pdf
Every. single. time. Mendel trots out that quote, he neglects to disclose that "this condition" in the document he is quoting is "a sticking EGR Valve". That condition does also happen (and could be because of rutting of the ski -jump inside, which might even be more common than they thought too), but they weren't talking about EGR cooler clogging there. I'm not sure how much Monday-morning quarterbacking is possible to do for EGR systems. The first one I ever had to work on was in a 1979 Mitsubishi. That system was clogged solid every time you turned around. I had to be in it multiple times a year. I've never known a maintenance-free EGR system. Toyota's is the closest I've ever seen.
I found several videos on YouTube explaining how to clean the EGR, but I’m unsure which would be best to share with my dealership—or if that’s even a good approach. When I first raised this issue with my local dealership, they hadn’t heard of it and found nothing in Toyota’s database. However, after I showed them online evidence, they admitted they’d seen several Gen III Prius models with blown head gaskets, and didn’t know why. It’s surprising Toyota corporate provides no guidance on this. Even after explaining the problem, the front desk staff seemed confused. He initially suggested replacing a part connected to the EGR, and I had to show him the specific information again before he understood. This is why I think sharing a video might help. If anyone has recommendations for good ones, that would be helpful, for me or others. My 2013 Prius, with 113,000 km (70,000 mi), has been nearly flawless. Other than routine maintenance, I’ve only replaced the brakes and auxiliary battery, and I’d love to keep it for another four years. Any guidance regarding the best resources to provide my dealership, video or other, would be greatly appreciated,. Searching, I see someone mentioned a nuts & bolts video as one good option?
It's not that surprising:" they rushed gen 3 to market, with (evident in hindsight) limitted testing, for both the newly-minted EGR system (head gaskets reliably blow by 150~200k) and the low-tension piston rings (runaway oil consumption, by about the same miles). In today's corporate culture, the typical backroom mission statement:
Thanks for that, Mendel. I see in your signature there are resources, and one is the video for EGR cleaning made by Nuts About Bolts. So I presume that might be a good one to show to my dealer? For a Prius with 70,000 miles, is an EGR clean sufficient, or should I consider having the cooler cleaned as well? Thanks!
If you aren't going to clean the cooler, no sence in doing anything else. That is the most important part. Second is the intake manifold. There is a small hole for each intake port. And the larger round hole going across the manifold for the holes. The pipe is too large to clog before the head gasket blows. The egr valve can also present a problem With your low mileage, it's not an issue. The dealer will NOT clean those parts, only replace them. You would have to go to an independent shop that might clean the parts.
