Last night I went to the drag strip and was talking to some 5.0 owners. One was telling/showing me how he removed the oil "tube" that goes from the engine to the air intake. I dont know what its called but he capped off were the tube connects to the intake manifold, than added a filter were the oil comes out from. So I was wondering why ford would do this? It makes no sense to me adding oil directly into the engine. Is there a good reason for this or should it be removed?

 

It's for emissions. You can do what he did, a lot folks use oil catch cans as well.

 

It's a PCV (positive crankcase vent) tube. It allows vapors to vent from the crankcase and be re-routed into the intake to be burned. As Joeywhat stated, it is an emissions thing. Cars back in the early 1960's and earlier simply had a "road draft tube" that vented these fumes out under the car.

 

And, as far as I know, there's zero performance benefit to removing the PCV tube, whether you decide to add the oil catch can or not. All it does is increase emissions for zero reason. Be smarter than that please.

 

It keeps the intake cleaner, and a dirty intake manifold will most certainly hurt fuel economy. Some small performance losses as well but not noticeable unless it's real bad.

 

As long as you empty and properly dispose of the catch can no emissions issue or pollutants problems.

And yes, it will keep the intake cleaner. If you are boosted it keeps the contamination out and possible octane compromising. If you are running a positive displacement blower for your boosted set up, that oil fron the PCV will clog the intercooler set up; even more reason on that forced induction.

 

As far as why Ford, or any manufacturer, does this rather than catch cans? Simple solution for the emissions that works. Think of how many people don't do basic maintenance. The catch cans wouldn't be emptied by average car owners, so the system doesn't work for the average owner and the emissions would be compromised, pollutants on the ground, and engines damaged.

 

103K on my car, still getting average of 23 MPG and highway only tanks as good as 27-28. Based on my experience, that fear is very overblown.

 

Not if your SC and you want the most out of the motor performance wise. Not to mention the recirculated vapor can cause issues.

 

Of course. I'm talking about stock to mildly modded motors.

 

PCV has been on cars since 1968. There is actually a performance advantage to PCV that nobody mentions. If the engine crankcase pressure builds up due to the accumulation of tiny escaping compression gases, this can increase pumping losses (the energy required to keep the crank, rods and pistons) moving. PCV allows a dignified exit for these pressures. This also prevents them from squeezing out dipsticks or gaskets over time.

On my 2012 MT, it drank about a quart and a half between oil changes and would fill a small catch can every month, despite making full compression and making 440 FW horse on a tune only. My 2014 auto, due probably to the fact it spends more time at lower rpm day to day, doesn't use any. It is a little less vigourous than the 2012 but, is still very stong.

 

Wow, my 2013 GT doesn't consume hardly any oil between changes. The last one I went 5k miles on full synthetic.

 

PCV is not strictly and "emissions thing". It's purpose is to remove blow-by pressure from the crankcase by pulling it into the intake manifold when the engine is under load (PCV valve closes when it sees idle/cruise vacuum).

An unfortunate side effect of pulling the blow-by into the engine is you're pulling some oil vapors as well. These condense and coat the intake tract with oil, as well as slightly lowering the octane of the air/fuel charge. An oil catch can is the best solution. You still get the benefits of PCV, but the oil is captured. Ford Racing actually recommends you install one with their Track Key/Track Cal tunes to reduce pinging. I have the Track Cal and I can say for sure that installing a catch can did just that, and it catches a few ounces every oil change interval.

I imagine OEMs don't use these because the slight benefit in performance isn't worth the risk of people forgetting to empty the catch can periodically.

 

Following that, my 2014 auto drinks absolutely no oil between changes and makes a tetch less power (7 or 8hp) than the 2012, on tune only.

 

Kyle, although there's zero performance benefit in removing the PCV tube, if you eliminate the factory PCV setup in favor of running breathers, the PCV tube should be removed, otherwise you only end up venting the crankcase through the passenger's side cam cover..

In order to get the full benefit out of running a breather setup, you want both driver and passenger side ports fully open along with replacing the oil cap with a breather as well which will then provide 3 sources for venting the crankcase rather than with just one port by leaving the PCV tube in place..

In addition, the PCV valve will also not open if there is no vacuum from the intake manifold.. Therefore you end up defeating the entire purpose of running a breather setup by not removing the PCV tube..



-Rocky

 

Actually the PCV valve closes under load during wide open throttle or under boosted conditions.. Under idle/part throttle and normal driving conditions, the PCV valve remains fully open..

 

Exactly why it's recommended to run an oil separator/catch can or disable the factory PCV system altogether by running breathers..