# Driving without pcv valve **URL:** \ **Category:** General Discussion\ **Tags:** f-150, ford\ **Created:** [February 19, 2022, 6:44pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586 "2022-02-19T18:44:17Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![leecohn254\_179638](https://avatars.discourse-cdn.com/v4/letter/l/f14d63/32.png) [@leecohn254\_179638](https://community.cartalk.com/u/leecohn254_179638)\ **Post date:** [February 19, 2022, 6:44pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/1 "2022-02-19T18:44:17Z")
What would happen if you drove without a pcv valve? Short term and long term? ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [February 19, 2022, 9:11pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/2 "2022-02-19T21:11:08Z")
It would act like a big vacuum leak, throw a check engine light and run poorly. Might cause damage. Might not. Why risk it for a $10 part? ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [February 19, 2022, 9:39pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/3 "2022-02-19T21:39:41Z")
> [@Mustangman](#): > > Why risk it for a $10 part? Exactly! Offhand, it’s hard to come up with a car part as cheap as a PCV valve. ---
**Author:** ![pyrolord314](https://avatars.discourse-cdn.com/v4/letter/p/6a8cbe/32.png) [@pyrolord314](https://community.cartalk.com/u/pyrolord314)\ **Post date:** [February 19, 2022, 10:00pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/4 "2022-02-19T22:00:34Z")
> [@VDCdriver](#): > > Offhand, it’s hard to come up with a car part as cheap as a PCV valve. Fuzzy dice or pine tree air freshener maybe 🤷🏻‍♂️ ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [February 19, 2022, 10:03pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/5 "2022-02-19T22:03:42Z")
> [@pyrolord314](#): > > Fuzzy dice or pine tree air freshener maybe Okay… good point. I should have stated that it’s hard to come up with a _functional_ car part as cheap as a PCV valve. ---
**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\ **Post date:** [February 19, 2022, 10:10pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/6 "2022-02-19T22:10:52Z")
valve stem. LOL sorry ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [February 19, 2022, 10:21pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/7 "2022-02-19T22:21:03Z")
Valve stem just cost me $83… with a TPMS sensor attached 😉 ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [February 19, 2022, 10:21pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/8 "2022-02-19T22:21:44Z")
You could plug off the vacuum line to the PCV valve, run a hose from the pcv port on the valve cover down toward the ground, to function as a road draft tube. You’ll make your motor oil as well as the environment dirtier. Why go back to 19 **62**? ---
**Author:** ![pleasedodgevan2](https://avatars.discourse-cdn.com/v4/letter/p/ad7895/32.png) [@pleasedodgevan2](https://community.cartalk.com/u/pleasedodgevan2)\ **Post date:** [February 19, 2022, 11:04pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/9 "2022-02-19T23:04:40Z")
The valve prevents an intake backfire from igniting the crankcase. If you have the hose, you need the valve. The system removes water vapor from the oil too. There was an open tube draining onto the road in the old days. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [February 19, 2022, 11:13pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/10 "2022-02-19T23:13:36Z")
> [@pleasedodgevan2](#): > > There was an open tube draining onto the road in the old days. … and the stench from many of those cars, when sitting behind them at traffic lights, was truly offensive. Is the OP yearning for the days prior to 1963, when PCV valves were mandated, or is he balking at spending a few bucks for a new PCV valve? ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [February 19, 2022, 11:14pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/11 "2022-02-19T23:14:16Z")
Maybe I don’t know better but if you plugged the end that goes to the intake and just left the other end open you would be spewing fumes and pollution with little effect on engine performance. Thinking my earlier cars the hose went to a filter in the air filter assembly. ---
**Author:** ![Hugemoth\_144444](https://avatars.discourse-cdn.com/v4/letter/h/ee7513/32.png) [@Hugemoth\_144444](https://community.cartalk.com/u/Hugemoth_144444)\ **Post date:** [February 20, 2022, 1:06pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/12 "2022-02-20T13:06:50Z")
Don’t see why you couldn’t plug the vacuum hose going to the PCV valve and vent the crank case like the pre 60s cars except it would produce more air pollution. Seems like it would prevent carbon build up on the intake valves on direct injection engines. ---
**Author:** ![JoeMario](https://avatars.discourse-cdn.com/v4/letter/j/3bc359/32.png) [@JoeMario](https://community.cartalk.com/u/JoeMario)\ **Post date:** [February 20, 2022, 1:15pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/13 "2022-02-20T13:15:12Z")
> [@leecohn254\_179638](#): > > What would happen if you drove without a pcv valve? Short term and long term? Assuming you did it properly, (e.g: plug off the vacuum line and create a road draft tube for the pcv port), then you’d see no short term difference. It has no effect on engine performance or fuel mileage. However, it’s the longer term that is more concerning. Without a functioning PCV valve, moisture will accumulate in the crankcase. That will reduce the life of your engine oil and will accelerate the formation of damaging sludge. Depending on where you live, disconnecting the PCV may be illegal, for environmental reasons. It is illegal in the USA. I’m curious about your motivation for doing this. I agree that some PCV valves are a big pain to access. But other than that, there is little to no downside for maintaining a functioning PCV. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [February 20, 2022, 1:16pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/14 "2022-02-20T13:16:32Z")
Why go to the effort to plug the PCV tube when replacing the valve is relatively easy and inexpensive? ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [February 20, 2022, 1:49pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/15 "2022-02-20T13:49:27Z")
> [@circuitsmith](#): > > Why go back to 1965? My father’s '63 Plymouth had a PCV system. Whether that became mandatory in '63–or perhaps in '62–I don’t recall. ---
**Author:** ![Hugemoth\_144444](https://avatars.discourse-cdn.com/v4/letter/h/ee7513/32.png) [@Hugemoth\_144444](https://community.cartalk.com/u/Hugemoth_144444)\ **Post date:** [February 20, 2022, 2:08pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/16 "2022-02-20T14:08:32Z")
The last car I owned without a PCV valve was a 1962 Falcon. It had the vent pipe that extended down near the oil pan. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [February 20, 2022, 2:17pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/17 "2022-02-20T14:17:45Z")
> [@Hugemoth\_144444](#): > > The last car I owned without a PCV valve was a 1962 Falcon. Yeah, I’m pretty sure that the 1963 model year was when PCVs were mandated in The US. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [February 20, 2022, 2:21pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/18 "2022-02-20T14:21:28Z")
> [@Hugemoth\_144444](#): > > Seems like it would prevent carbon build up on the intake valves on direct injection engines. Probably not. > **[Considerations on Carbon Deposit Formation in Gasoline Direct Injection Engine...](https://docplayer.net/38978662-Considerations-on-carbon-deposit-formation-in-gasoline-direct-injection-engine.html)** > > Considerations on Carbon Deposit Formation in Gasoline Direct Injection Engine Gyu-Sob Cha GS Caltex Corporation Contents Introduction : Motivation & Objective of Research Preliminary Test ---
**Author:** ![JoeMario](https://avatars.discourse-cdn.com/v4/letter/j/3bc359/32.png) [@JoeMario](https://community.cartalk.com/u/JoeMario)\ **Post date:** [February 20, 2022, 2:41pm UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/19 "2022-02-20T14:41:37Z")
The “PCV system” for my 1964 Dodge slant-6 engine was a crankcase breather cap on the valve cover, with a hose routed to the air filter housing. As the engine got old, the piston ring blow-by grew worse and caused the engine air filter to get soaked with oil. I replaced that hose with a homemade road draft tube and drove for years without a problem. That was in an era when one would often see cars on the road that burned oil and produced lots of tailpipe smoke. I’m glad we see little of that with today’s engines. ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [February 21, 2022, 3:04am UTC](https://community.cartalk.com/t/driving-without-pcv-valve/182586/20 "2022-02-21T03:04:30Z")
> [@JoeMario](#): > > As the engine got old, the piston ring blow-by grew worse and caused the engine air filter to get soaked with oil. > > I replaced that hose with a homemade road draft tube and drove for years without a problem. Around 1991 had an old Oldsmobile (mid-60’s) that I bought for $175. It burned oil like crazy, despite the straight 40 weight oil I put in it. The PCV/breather system was simply overwhelmed, but somehow the spark plugs never fouled out. My answer was to buy a 25’ roll of 3/4 heater hose and run the “new” breather tube down along the frame and ended it next to the tailpipe, keeping all that blowby away from the passenger compartment. I used it as my drivearound junker for 2 years, then gave it to my ex-girlfriend who used it to commute 60 miles a day for another year and then sold it for $250.