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Hey everyone! I have a question on “modding” the PCV system on my 09 Corolla.. Basically, there is the PCV valve (with a hose) that leads to the intake manifold to re-burn the crankcase gasses. There’s another tube that leads to the valve cover, which comes from the air intake (I assume this is to help purge crankcase gasses.)
I was wondering if I would be able to seal off the inlet for the valve cover, to see if I could reduce the pressure on the system (PCV valve is dumping too much oil)
I tested the vacuum with an OBD2 tool. Vacuum was at -20 inches of Mercury at idle. Roughly around -12 inches at 2000-3000RPM, and at WOT, there was no vacuum. According to the OBD tool, there was +15 inches of Mercury at WOT. Not sure if that’s a fluke though… So I’m just seeing if there are ways to reduce manifold pressure.
TL;DR – Can I seal off the inlet tube to the crankcase (NOT THE PCV VALVE) to help with crankcase pressure? Will there be any ill effects?
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I believe the air inlet to the valve cover helps cool the oil
and gases. It was engineered that way.It does serve a purpose.The air inlet does not have manifold vacuum, that only exists after the throttle plate. The vacuum there is very, very slight, only depending on how clogged your air filter is. If you’re getting too much oil getting into the intake, that’s usually due to too much crankcase blowby caused by worn rings. There are aftermarket “oil catcher” dohickies you can add that will intercept the oil. You can also just add some length of oil-rated hose, angled and held up with coat-hangers such that any oil that collects on its inside surface flows back into the valve cover.
[quote=”ChaoticWeaponry” post=79327]Hey everyone! I have a question on “modding” the PCV system on my 09 Corolla.. Basically, there is the PCV valve (with a hose) that leads to the intake manifold to re-burn the crankcase gasses. There’s another tube that leads to the valve cover, which comes from the air intake (I assume this is to help purge crankcase gasses.)
I was wondering if I would be able to seal off the inlet for the valve cover, to see if I could reduce the pressure on the system (PCV valve is dumping too much oil)
I tested the vacuum with an OBD2 tool. Vacuum was at -20 inches of Mercury at idle. Roughly around -12 inches at 2000-3000RPM, and at WOT, there was no vacuum. According to the OBD tool, there was +15 inches of Mercury at WOT. Not sure if that’s a fluke though… So I’m just seeing if there are ways to reduce manifold pressure.
TL;DR – Can I seal off the inlet tube to the crankcase (NOT THE PCV VALVE) to help with crankcase pressure? Will there be any ill effects?[/quote]
No, you can’t, without problems. The air tube is there to keep the crankcase from drawing into a vacuum too much, in fact if you seal off the air inlet tube you are likely to start sucking oil in through the PVC system and into the intake.
The hose is there to allow fresh, filtered air to enter the crankcase and to relieve the pressure at low vacuum and whatever the PCV valve can’t handle.
If you block that hose the engine will build up pressure may cause oil leaks everywhere. It will also promote sludge build up.
So in that case. Don’t do it. 😛 Alright, on to figuring out other reasons as to why my engine burns oil. Oil control rings are the next suspect.
[quote=”Raistian77″ post=79373]are you getting oil in the breather tube and intake?[/quote]
Oil in the PCV hose and intake manifold. I took the manifold off last week, was holding around a cup of oil. Car burns 1 quart every 2000 miles.[quote=”ChaoticWeaponry” post=79392][quote=”Raistian77″ post=79373]are you getting oil in the breather tube and intake?[/quote]
Oil in the PCV hose and intake manifold. I took the manifold off last week, was holding around a cup of oil. Car burns 1 quart every 2000 miles.[/quote]Okay, there is a TSB for your vehicle pertaining to excessive oil consumption.
The repair is a ECM re-flash to update the software.
I recommend going to the dealer and asking them about TSB 0145-08
[quote=”Raistian77″ post=79393][quote=”ChaoticWeaponry” post=79392][quote=”Raistian77″ post=79373]are you getting oil in the breather tube and intake?[/quote]
Oil in the PCV hose and intake manifold. I took the manifold off last week, was holding around a cup of oil. Car burns 1 quart every 2000 miles.[/quote]Okay, there is a TSB for your vehicle pertaining to excessive oil consumption.
The repair is a ECM re-flash to update the software.
I recommend going to the dealer and asking them about TSB 0145-08[/quote]
Already been reflashed for about 10,000 miles. Very little, if no change at all.
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