Blow-by?
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From: Newmarket, Ontario
Blow-by? Running car at 4500-5000 rpm no smoke from exhaust. Now get into boost a little, and it starts smoking....
My thoughts, because it does not smoke at 5000 rpm without boost that means when the turbo is getting LOTS of oil pressure it is draining properly (no restrictions on oil drain, which could also cause the problem).
What could cause the car to smoke when you get into boost but not otherwise, could it be getting through the PVC to intake, is it for sure blowby, any ideas?
-edit-
My PVC line is still connected to my intake, could I be pressurizing the block which is causing problems???
My thoughts, because it does not smoke at 5000 rpm without boost that means when the turbo is getting LOTS of oil pressure it is draining properly (no restrictions on oil drain, which could also cause the problem).
What could cause the car to smoke when you get into boost but not otherwise, could it be getting through the PVC to intake, is it for sure blowby, any ideas?
-edit-
My PVC line is still connected to my intake, could I be pressurizing the block which is causing problems???
Last edited by bigturboz28; Mar 15, 2006 at 06:22 PM.
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Another thought, not only is the PVC system sit connected, so is the air line from the TB to the valve cover (since my block should definately be pressurized, would this contribute to the problem)?
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Oil dipstick pushed out. In severe cases you may get into detonation as your oil control goes south. More oil could enter the combustion chamber which leads to detonation.
Oil leaks can develop in the front and rear oil seal. LSx engines have o-ring style gaskets throughout so the easiest path for leakage is the crankshaft seals.
If your pcv system is plumbed into the air intake you can push oil into your intake system which may wind up on your mass airflow meter.
Oil leaks can develop in the front and rear oil seal. LSx engines have o-ring style gaskets throughout so the easiest path for leakage is the crankshaft seals.
If your pcv system is plumbed into the air intake you can push oil into your intake system which may wind up on your mass airflow meter.
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turbo seals could be blown or getting there, if your pressureizing the crankcase look forward to blowing every gasket.
i blew 2 oil pan gaskets on my other n/a gone turbo'd car as a result of poor pcv system
get under there and look for leaks
just curious what size are your feed and return lines
lastly whats your pcv system look like?
i blew 2 oil pan gaskets on my other n/a gone turbo'd car as a result of poor pcv system
get under there and look for leaks
just curious what size are your feed and return lines
lastly whats your pcv system look like?
Originally Posted by bigturboz28
PCV system is stock.
Changes made last night...
Plugged line on TB (that used to goto valve cover).
Valve cover line now goes to atmosphere.
Changes made last night...
Plugged line on TB (that used to goto valve cover).
Valve cover line now goes to atmosphere.
that won't help, you need something thats gonna pull the gases out of the valve cover, you could run a hose to the bottom of the car and have a old style road draft tube
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Since you're still on the stock block, I'd recommend compression testing on #7 at least, seeing if you're still OK there. Mine was fine with my 400 rwhp N/A setup, but wouldn't hold pressure once higher boost started to come on during tuning.
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Can't see anymore smoke, I guess pressurizing the crank case is bad.. (we all make dumbass mistakes). Do I need to "pull" gases from crankcase or is venting to atmosphere enough? Also shouldn't the stock PCV prevent boost from getting in the crank i.e. not blow oil into intake at boost, why do people use catch cans, for oil consumption issues or what?
Originally Posted by bigturboz28
Can't see anymore smoke, I guess pressurizing the crank case is bad.. (we all make dumbass mistakes). Do I need to "pull" gases from crankcase or is venting to atmosphere enough? Also shouldn't the stock PCV prevent boost from getting in the crank i.e. not blow oil into intake at boost, why do people use catch cans, for oil consumption issues or what?
yes pressurizing the crankcase is really bad lol
venting to the atom isn't gonna be enough,people run catch cans so oil doesn't get into the compressor housing and intake
Last edited by 89Formulaws6; Mar 17, 2006 at 03:10 AM.
the way everyone talks, they make the pcv system on the ls1 sound soo complicated. someone care to share the make up of it. i would figure its just a hose going from the t/b/intake to the pcv valve itself thats in the valve cover.
look a few posts up at my last one
look a few posts up at my last one
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Your right, it is that simple. But is a negative pressure "sucking" crankcase fumes out needed, or can I just rely on whatever presssurizes the crank (pistons moving, slight blowby, whatever) to make enough pressure to ventilate the crank case, OR do I even need to ventilate the crank case? Is the PCV system entirely for emissions, if that is the case, breathers are for me.
i'm gonna say going boost your gonna need something to pull the gases out, some cars can work fine without any pcv mods. but those would be a stock turbo car.
pcv is for emissions yes. but just slapping breathers on there i don't think is gonna cut it when going boost.
like i said if you run a hose from the pcv to a catch can,so you don't get oil in the turbo, then run it from the catch can to the and put a fitting in the intake pipe on the compressor side of the turbo you'll have the "sucking" out of the gases when you go under boost.
if you do this you should be fine and have a nice pcv setup and still have a little vaccum left in the crankcase to help with sealing the rings better
and ofcourse, you run a breather filter on the other valve cover so it can suck fresh air into the engine
pcv is for emissions yes. but just slapping breathers on there i don't think is gonna cut it when going boost.
like i said if you run a hose from the pcv to a catch can,so you don't get oil in the turbo, then run it from the catch can to the and put a fitting in the intake pipe on the compressor side of the turbo you'll have the "sucking" out of the gases when you go under boost.
if you do this you should be fine and have a nice pcv setup and still have a little vaccum left in the crankcase to help with sealing the rings better
and ofcourse, you run a breather filter on the other valve cover so it can suck fresh air into the engine
Last edited by 89Formulaws6; Mar 17, 2006 at 12:13 PM.
if you thought about maken the vaccum source the intake manifold and added just a breather filter
every time you get into boost the PVC seals shut
this makes the crank case only form of venting be the little air filter on the top of the motor and its not going to vent much
if you had the vac source be the turbo
at the point where your running ( the motor it's hardest ) it would be getting the most air sucked out of the crank case
this would be ( in theory ) some thing like the "crank case vaccum pump" that the "old timers" used on the carb'd cars to gain 40 more HP out of a big block V8
the theory goes some thing like this ( if you find a way to gain vaccum in the crank case - the rings will seal better - all the blow-by will be sucked away - and the oil may also be sucked to the extrematies of the motor
but you say " why do i need to run that little $10 air filter on the valve cover ?"
because "blow-by" I would like a little fresh air to help minamize the chance of all the extera fuel from building up in the crank case and then finding a spark from the under side of the piston
clear things up a lil bit?
every time you get into boost the PVC seals shut
this makes the crank case only form of venting be the little air filter on the top of the motor and its not going to vent much
if you had the vac source be the turbo
at the point where your running ( the motor it's hardest ) it would be getting the most air sucked out of the crank case
this would be ( in theory ) some thing like the "crank case vaccum pump" that the "old timers" used on the carb'd cars to gain 40 more HP out of a big block V8
the theory goes some thing like this ( if you find a way to gain vaccum in the crank case - the rings will seal better - all the blow-by will be sucked away - and the oil may also be sucked to the extrematies of the motor
but you say " why do i need to run that little $10 air filter on the valve cover ?"
because "blow-by" I would like a little fresh air to help minamize the chance of all the extera fuel from building up in the crank case and then finding a spark from the under side of the piston
clear things up a lil bit?
