TOPIC: PCV 2008 Honda Accord 2.4L

I disabled the PCV valve on this vehicle by filling the PCV valve with JB Weld, allowing that to harden overnight then reinstalling just as it was. The results were better acceleration and increased mileage. These were observed and not measured, so no numbers to share. My daughter also drives this vehicle and I did not tell her of the mods or to expect any differences. Without being asked, she spoke up to say that, "The car takes off better than before." As far as mileage, we have both observed fewer fill ups. I would guess the milage gain to be up to 3mgp.
The PCV system is an EPA mandated (for the manufacturer) tech that actively draws vapors from the crankcase and into the intake. The idea is that the vapors are burned with normal combustion rather than escaping into the atmosphere. This system uses engine vacuum and therefore decreases engine vacuum. Engine vacuum is critical to efficiency. The PCV system neccessarily decreases engine efficiency. Moreover, the PCV system introduces water vapor into the crankcase which contaminates engine oil thus reducing oil performance and life. Which is better: Decreasing efficiency to mitigate pollution or increasing efficiency to produce less pollution? Also, with more available tourque, would one not need to use less throttle?
A concern expressed by some is that without the PCV system, vapors accumulate and build positive pressure within the crankcase resulting in stress to the oil seals. This is absolutely impossible as all engines have passive vents, usually located in the intake between the air filter and throttle body. So, whatever vapors need to vent, still make thier way into the intake but without robbing precious vacuum.
Provided that the PCV valve is easily accessible on a given vehicle, this is the easiest and cheapest mid-yield mod that one can do.

This is marvelous, Ethan! Thank you for backing up what I have been teaching folks for years.

One thing that might help in your vision is to consider the PCV to be NOT a "Pollution Control Device" but rather a "Pollution CREATION Device," as that is EXACVTLY what it does. In decreasing fuel efficiency, it CONCLUSIVELY establishes this valve as exactly that. All emissions disappear with complete combustion.

Power goes up.

Mileage goes up.

Engine oil life is extended.

And emissions are eliminated (or drastically reduced).

Way to go, amigo!

You're welcome, Ron. Also, with this mod already done, a vehicle is ready to take advantage of the Gadgetman Groove at a future time.

So did you reroute those PCV lines to inbound air flow ?

Ethan I want to thank you for this. You just explained clearly and concisely the story on the PCV valve. OF course, Ron reinforced your thesis.
Maybe Ron ought to talk to you about writing descriptions of the different mods and the processes that drive them. you write like an author would. I've tried, but I'm too wordy.

And I second your results. I had dramatic results w the PCV mod on an old Dodge 225 Slant six engine whose carb was un-Grooveable. Capping the vac. port on the carb. base, then re-routing the PCv hose cured an idle issue it had had for years.

Thank you!

Tracy G

Hi Ethan! Do you have any updates on how your mod is doing?

I did no rerouting. The inlet for the PCV system located between the valve cover and the intake hose(between air filter and TB) is now the sole vent for the crankcase. If you're curious about the condition of the oil: I did this mod when the oil was at 50% remaining life, so I put about 2500 miles on it after the mod. Just changed the oil and it had the same appearance as usual. No evidence of moisture or anything wierd whatsoever. This is in northern CO with temperatures ranging from 0-50F this time of year. Mostly dry climate but with occasional spikes in humidity up to 80%. My conclusion thus far is that no additional venting is needed. The inlet has no valve to restrict flow in either direction. Any pressure buildup in the crankcase has an easy out. I can imagine, however, that heavier vapors coming off of the oil may not make it up to the valve cover due to density. The changing condition of the fresh oil change over the coming weeks should provide obvious evidence.

You're welcome! I just logged on for the first time since my original post. I went looking for something else and noticed your's and other's replies. Did not expect that. What a cool forum!!

All is good. No wierdness with the oil, which is/was my only real concern. The engine runs better. No hard data to share, just subjective observations from both of us in my household that drive this vehicle.

Sounds good. Perhaps, the car is driven such that it gets sufficiently warmed up to eliminate condensation in the crankcase.
Better power-driveability is almost always the result of blocking and/or re-routing the PCV.

good!

Tracy G

HI ETHAN! How is the accord doing? Any recent results or gains to report? Let us know either way!