HELP, 418 has to much crankcase pressure, blowing out everywher!!!!
04-07-2012, 06:47 PM
#1
HELP, 418 has to much crankcase pressure, blowing out everywher!!!! ok i got a 418 ls3, and when you get on it and get the rpms high this thing builds up so much crankcase pressure it was blowing the oil dipstick out and shooting oil every where, we added a catch can and zip died the dipstick down and everything seemed fine until one time I got on it and saw all kinds of smoke out the back, got the car on a lift and looked like it blew oil out the back of the main seal (i dont think it damaged it) so then we added a breather, things seem to be ok from there but then after about 500 miles of strait driving I noticed that oil was leaking out of the breather.
What is going on with this thing, i figure a catchcan and breather would stop excess crankcase pressure from doing this,
I really need help here i dont want my car shooting oil everywhere when I get on it.
What is going on with this thing, i figure a catchcan and breather would stop excess crankcase pressure from doing this,
I really need help here i dont want my car shooting oil everywhere when I get on it.
04-07-2012, 06:56 PM
#2
You should not use a breather. How is your PCV system setup? If you do not have one, you should. I would do a compression test and see what you come up with there, then a cyl leakdown. I would do the tests cold first then hot. They should tell you everything you need to know.
04-07-2012, 07:10 PM
#3
i wouldnt think it would be bad rings, it did 508 on the dyno,
its not running a pvc system its running a catchcan. the driver side valve covor is running to the passenger side covor then the passenger side has a breather.
then the catchcan runs to the intake and the valley cover
its not running a pvc system its running a catchcan. the driver side valve covor is running to the passenger side covor then the passenger side has a breather.
then the catchcan runs to the intake and the valley cover
04-07-2012, 07:33 PM
#4
Valley cover port goes to catch can, which goes to intake. I used two breathers on pass cover (One on oil cap, one on vent tube), one on driver cover (rear vent tube by firewall), and it finally stopped blowing oil (429 ls3). An alternative is a big boy valve cover setup with -10 or -12 vents to a catch tank, and a -10 or -12 off of the valley cover.
One breather on the VCs is not enough.
One breather on the VCs is not enough.
04-07-2012, 07:50 PM
#5
PS breathers only work when there is more pressure in the crank case than is outside the engine. At that point, the oil mist is already about to come out and the pressure has built to more than is acceptable.
There is never a need for breathers on a street driven car IMO. The low pressure system caused by a properly working PCV system will evac the crank case pressure. HMM maybe thats why its called a PCV system? Valley to intake, valve cover/s to the CAI.
But even if it did xxx HP on the dyno, using low tension oil rings and them being improperly setup can cause extreme oil consumption and excessive blowby.
There is never a need for breathers on a street driven car IMO. The low pressure system caused by a properly working PCV system will evac the crank case pressure. HMM maybe thats why its called a PCV system? Valley to intake, valve cover/s to the CAI.
But even if it did xxx HP on the dyno, using low tension oil rings and them being improperly setup can cause extreme oil consumption and excessive blowby.
04-07-2012, 07:52 PM
#7
I would not. I would build a proper pcv system that would tie the valve covers together and run into the cai. You can put a catch can on them also if you wish, but the factory valve covers have baffles which help cut down on the oil mist, but its still there.
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04-07-2012, 07:58 PM
#9
btw I think it was running a stock pvc system when it shot the dipstick out, then with the catchan system and then dipstick ziptied oil came out of the rear main seal, and now the breather, its going for the path of least resistence I guess, I got a buddy in town that should be real knowdegle about this and he runs a built 440 I will probably duplicate his setup and see what happens, if it dont fix it then I guess it could be bad rings and theres not much I can do about that.
04-07-2012, 07:58 PM
#10
Well there are a few ways to do it. Most people leave the driver side capped with that Gm rubber fitting and run off the pass side which has the tube running forward.
On yours, I would run a line from the driver cover around back and t into a line from the pass cover, then run them into the tube that should be going into the top of your TB.
Since you have aftermarket covers, they should have a small orifice in them, so there is no need for a pcv valve per se...
On yours, I would run a line from the driver cover around back and t into a line from the pass cover, then run them into the tube that should be going into the top of your TB.
Since you have aftermarket covers, they should have a small orifice in them, so there is no need for a pcv valve per se...
04-07-2012, 08:07 PM
#13
Well that will help, but based on what you are saying, there is another cause for that pressure. But since it builds so much, you may want another catch can or a dual can setup like the rev kit that Colorado Speed sells. That would prob be most helpful and less clutter.
