I know the 3rd Gen Prius needed the EGR cleaned but haven't seen anything about our 4th Gen. I have a 2017 and 2021 Prius and both have had zero issues but are both getting close to 50,000 miles and I'm wondering if the EGR needs maintenance. FWIW: Transmission job is a breeze in these cars....just drain and fill....I love owning Toyotas!!
There is no need to clean the EGR system on a Gen 4 Prius. The design of the Gen 4 was changed compared to the Gen 3. Do a search on this Gen 4 forum and you will find only a few threads about cleaning the EGR system.
@jerrymildred, working at Tampa Hybrids, reported a 4th gen Prius owner insisted (against their advice) to get an EGR system cleaning. He reported the car had over 300k miles, and carbon build up was minor. I recall a press release for gen 4 (somewhere...), Toyota noted the car had a revised EGR system. They also keep pretty quiet, about gen 3 EGR...
Yes, I agree. The more we touch things, more things can go wrong. That's why US NAVY do oil analysis before changing their oil and such. More down time is not good.
Should the Gen 4 PVC be replaced on a regular basis, i.e. 75k miles? I was told if PVC clogs it may add pressure to the EGR????
No, PCV valve is no longer issues in any Toyota since 2005. Most Toyota engines have buffle that separate oil from crankcase fume and reduce the amount of oil go through PCV lines. The hybrid intake always contains some trace of oil, water, and fuel mixture because the engine start and stop very often. We never heard any PCV valve problem since Gen 2.
Horrible advice. 2010-2015 PCV and even Gen 4 can clog up and should be changed periodically. They are all of about $7, just do it!
don't fix it it ain't broke. PCV valve is cheap, but the labor to do that is not. My 06 Prius, 04 Sienna, and Corolla hybrid all are still original, 2 of them already over 220k miles without any oil consumption issue. But if at a point you are right there, like when cleaning intake manifold, changing it does not hurt. Just to make you feel good about it.
Lurkers beware, not all the advice given on this website is sound. Your vehicle is your freedom and your investment, keep everything maintained.
One of the times I've had the intake manifold off, I removed the PCV valve, shot carb cleaner through it from both ends, gave it a good shake. It tested ok (per attached). Replacement is expedient, but if you've not had the foresight to have the replacement on hand, cleaning is ok. I cleaned the threads and applied a ring of Loctite Threadlocker Blue 243 (non-permanent, oil-tolerant thread lock), to prevent oil bloom. There is a Toyota spec adhesive (per attached). Torque is 15 ft/lb
Exactly, do not trust what we post or opinion alone about things. So far, there is no maintenance schedule nor TSB about PCV valve in Prius 4. I am not aware if there is any TSB related to PCV valve in 2010 or newer Toyota/Lexus. In the past, late 90s we have TSB and voluntary recall/campaign on replacing PCV valves in V6 Toyota & Lexus. But not in the past 20 years.
That is true that Hybrid has Atkinson and Otto cycles, depending on the power demands. In Atkinson cycle, The effective compression ratio is reduced—for the time the air is escaping the cylinder freely rather than being compressed—but the expansion ratio is unchanged (i.e., the compression ratio is smaller than the expansion ratio). There is a moment during compression step, the intake valve are opened and some of the fume, water vapour are going back to intake manifold. That's why we often found mixture of water fuel and oil below the throttle body in all hybrid. However, that's nothing to do with how the PCV valve operate. It only channel out the blowby gas that go to the crankcase in any engines. In fact, hybrid engine has less blowby than non hybrid. Diesel and turbo engine naturally have tendency have higher blowby rate from higher compression ratios.
