PCV Delete thread
PCV Delete thread
Someone convince me that I shouldn't go forth with this mod.
I've read BULL's remarks, and they are very convincing.
I've watched videos of 'failures' (mainly oil seepage issues, which is not the issue i'm worried about)
Someone stated that it may draw unmetered air through the breather tube as the piston sucks air in and I guess some air seeps into the combustion chamber
I've also heard about the vacuum issue during idle, but during idle how much damage could be done from having no crank case pressure?
Otherwise, I don't see how having an unpressurized crank case would be harmful for the engine
I've read BULL's remarks, and they are very convincing.
I've watched videos of 'failures' (mainly oil seepage issues, which is not the issue i'm worried about)
Someone stated that it may draw unmetered air through the breather tube as the piston sucks air in and I guess some air seeps into the combustion chamber
I've also heard about the vacuum issue during idle, but during idle how much damage could be done from having no crank case pressure?
Otherwise, I don't see how having an unpressurized crank case would be harmful for the engine
Someone convince me that I shouldn't go forth with this mod.
I've read BULL's remarks, and they are very convincing.
I've watched videos of 'failures' (mainly oil seepage issues, which is not the issue i'm worried about)
Someone stated that it may draw unmetered air through the breather tube as the piston sucks air in and I guess some air seeps into the combustion chamber
I've also heard about the vacuum issue during idle, but during idle how much damage could be done from having no crank case pressure?
Otherwise, I don't see how having an unpressurized crank case would be harmful for the engine
I've read BULL's remarks, and they are very convincing.
I've watched videos of 'failures' (mainly oil seepage issues, which is not the issue i'm worried about)
Someone stated that it may draw unmetered air through the breather tube as the piston sucks air in and I guess some air seeps into the combustion chamber
I've also heard about the vacuum issue during idle, but during idle how much damage could be done from having no crank case pressure?
Otherwise, I don't see how having an unpressurized crank case would be harmful for the engine
I dont support an open system:
Open PCVs and Breathers
Open breathers only
What I do support is a catch can:
Between the PCV
Between PCV and breathers
I have way to many reasons why and with today's economy you'd need as much help as possible in the recycling department. These gasses can be burnt and can aid in fuel efficiency, they can keep the crankcase at 0ps or in the negative which helps the engine make power, efficiency and save oil seals at the same time. They don't create any type of smell and just works.
Any type of modification to the system that does not incorporate the catching of these gases/cleaning/filtering will result in a bit lower efficiency with an added smell and engine issues much later in the future. And I'm talking 60K miles of data comparison.
In comparison the deleted engine will start leaking from seals much earlier than a recirculated one.
Every production car has a type of crank case ventilation, this ventilation is extremely recommended for folks with aftermarket oil coolers since the cooler now maintains the oil at lower temps overall. The now lower oil temps will keep more gasses and vapor than at 200+ degrees that it would normally see on a spirited run. Add E85 to this which typically introduces even more fuel into the system and you'll end up with more oil dilution.
A confirmation of this theory would require an oil analysis to confirm. We should typically see higher fuel deposits and oil deterioration in a deleted system.
Conclusion: hover around some of the threads that have spoken about this and tailor your own system. I found some 90deg angled plastic fittings that give me a better angle for the PCVs. I'm running a "factory" system and have not had any issues with oil spray, it's there, it's about less than 1/4 of oil in 3k miles however I'm not sure if this is a mix of oil burning from the pistons or vapor introduced. There is no need to remove a crank case ventilation system. I'll have more info on this in the future.
I have some oil seepage on the driver's side, apparently coming from the valve cover seals.
This happened after I installed catch cans on the system (not a delete).
I was going to do a delete by replacing the PCV valves with 0.5" openings and adding hoses with breathers. And putting hoses+breathers on the inlet sides.
This happened after I installed catch cans on the system (not a delete).
I was going to do a delete by replacing the PCV valves with 0.5" openings and adding hoses with breathers. And putting hoses+breathers on the inlet sides.
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gpzkat
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Jan 31, 2026 10:31 AM







