Crankase venting vs PCV "valve" vs BOOST
Thread Starter
TECH Fanatic
Joined: Jul 2022
Posts: 1,037
Likes: 390
From: Alaska
Crankase venting vs PCV "valve" vs BOOST 5.3 LS, TSP208/214 .551" lift, stock compression.
VSR78/75 .96AR
Passenger side Rocker vent hose with TEE fitting, 3/8" chinese "breather/filter"
Is it possible that under BOOST conditions, ( 175kPa) the maniofld pressure pushes BACK through PCV in driver's side rocker cover, overpressure crankcase ?
After a good romp, with 4 or 5 seconds in BOOST, close throttle and I get a YUGE oil smoke cloud out the exhaust: Oil cloud like a worn out 62 Dodge Dart.
Think I need more venting, maybe a TEE fitting, check valve and another breather on the drivers side PCV hose ?
Tee before or AFTER Pcv valve ?
Turbo is near cherry new, install only 3 weeks ago, 100 miles on road, dozen heat cycles, probably have a grand total of 200 seconds in actual BOOST.
1/2 inch Turbo drain hose, angled steeply DOWN all the way to 1/2" npt front of oilpan. Test with tranny fluid funnel shows I can POUR diesel+ATF mixture through the drain hose, will pass 2 gallons in 30 seconds easily.
Looking for recommendations.
Possible that my compressor seals are bad out of box ?
VSR78/75 .96AR
Passenger side Rocker vent hose with TEE fitting, 3/8" chinese "breather/filter"
Is it possible that under BOOST conditions, ( 175kPa) the maniofld pressure pushes BACK through PCV in driver's side rocker cover, overpressure crankcase ?
After a good romp, with 4 or 5 seconds in BOOST, close throttle and I get a YUGE oil smoke cloud out the exhaust: Oil cloud like a worn out 62 Dodge Dart.
Think I need more venting, maybe a TEE fitting, check valve and another breather on the drivers side PCV hose ?
Tee before or AFTER Pcv valve ?
Turbo is near cherry new, install only 3 weeks ago, 100 miles on road, dozen heat cycles, probably have a grand total of 200 seconds in actual BOOST.
1/2 inch Turbo drain hose, angled steeply DOWN all the way to 1/2" npt front of oilpan. Test with tranny fluid funnel shows I can POUR diesel+ATF mixture through the drain hose, will pass 2 gallons in 30 seconds easily.
Looking for recommendations.
Possible that my compressor seals are bad out of box ?
Last edited by Full Power; Jul 3, 2024 at 07:43 PM. Reason: space
I had the exact same problem, I ran a line from the DS PCV to an oil separator (cheap one) to a check valve, then to manifold, cured problem. Boost is prob. creating pressure in the crankcase, creating problems. I just plugged the PS VC tubes, used a filtered oil cap. I always use an oil sep. if using a PCV valve, you would be surprised how much oil it sucks in the engine.
Launching!
Joined: Jan 2002
Posts: 299
Likes: 41
From: Detroit, Murder City
Thread Starter
TECH Fanatic
Joined: Jul 2022
Posts: 1,037
Likes: 390
From: Alaska
Thank you Greg.
I need to fabricate a big catch can for drivers (PCV ) side.
Probably try to fit some hose barbs to a quart size STIHL gasoline can, use the metal screw cap at bottm for a drain.
Maybe I can solder some little copper tube stubs to the steel can.
My ( 2003 ) 5.3 liter has a genuine, old style spring loaded PCV valve. I was surprised by that, Had thought they'd all gone fixed orifice long ago.
Seems like the spring loaded unit would ALSO function as a check valve, effectively blocking manifold pressure from flowing INTO the rocker cover.
Could maybe try to fit a grommet into catch can, mount the PCV valve direct push-in to catch can, then second fat (1/2") hose from can to rocker cover, small breather/filter on top of can.
I need to fabricate a big catch can for drivers (PCV ) side.
Probably try to fit some hose barbs to a quart size STIHL gasoline can, use the metal screw cap at bottm for a drain.
Maybe I can solder some little copper tube stubs to the steel can.
My ( 2003 ) 5.3 liter has a genuine, old style spring loaded PCV valve. I was surprised by that, Had thought they'd all gone fixed orifice long ago.
Seems like the spring loaded unit would ALSO function as a check valve, effectively blocking manifold pressure from flowing INTO the rocker cover.
Could maybe try to fit a grommet into catch can, mount the PCV valve direct push-in to catch can, then second fat (1/2") hose from can to rocker cover, small breather/filter on top of can.
