Excessive Crankcase Pressure, help???
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From: Plano, TX
Excessive Crankcase Pressure, help??? I'm not sure what is causing this since I know nothing about LS1's but last night the car refused to idle properly without surging from 300rpm to 1000rpm then usually dying. coolant and oil temp were right around 178degrees. oil pressure was around 33-40 from idle to 2k rpm.
The only thing I've done with crankcase changes is removing the pcv tubing into the intake as I've seen done on other LS1's. I have a breather to allow ventilation, but it doesn't seem to be working cause I noticed a cloud of something come from under my car while driving and when I stopped the dip stick had popped out of the tube about an inch and oil had spit out all over the passenger side of the engine compartment.
Anyone every had this experience or have any suggestions?
Thanks
Rob
The only thing I've done with crankcase changes is removing the pcv tubing into the intake as I've seen done on other LS1's. I have a breather to allow ventilation, but it doesn't seem to be working cause I noticed a cloud of something come from under my car while driving and when I stopped the dip stick had popped out of the tube about an inch and oil had spit out all over the passenger side of the engine compartment.
Anyone every had this experience or have any suggestions?
Thanks
Rob
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From: Plano, TX
http://www.ls1.com/forums/showthread...ght=pcv+delete
Got info on it. Anyone doing a PCV delete on an LS1 might want to check this thread out. Keith Craft Motorsports in Plano has experienced customers ruining their motor usuing the catch can system.
It appears LS1's need a vaccum evacuated system to relieve the crankcase pressure vs just venting. I'm not quite sure how venting won't perform the same function but there is hard evidence that shows it has to have a suctioned ventilation setup. Good luck everyone.
Got info on it. Anyone doing a PCV delete on an LS1 might want to check this thread out. Keith Craft Motorsports in Plano has experienced customers ruining their motor usuing the catch can system.
It appears LS1's need a vaccum evacuated system to relieve the crankcase pressure vs just venting. I'm not quite sure how venting won't perform the same function but there is hard evidence that shows it has to have a suctioned ventilation setup. Good luck everyone.
Last edited by Tweakd; Nov 11, 2004 at 11:20 AM.
this year i had a problem with blowing oil all over the underside of the car out of the bottom of the dipstick tube. i put a breather in place of the oil fill cap and it solved the problem. i use stock pcv setup..
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The catch can is not recommended from this article and Keith Craft Motorsports won't run the catch can either. They just replaced a motor due to a catch can. Either do the LS1 to LS6 pcv conversion http://www.ls1howto.com/index.php?article=18 or possibly try a breather in the oil filler cap using the stock PCV system. Just some more info I've dug up on this problem.
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I'm real confused. I have the LS6 PCV system currently but dont want the oil behind the throttle body others are experiencing. I have a catch can I am ready to install but isnt there still a vacuum being pulled as one line goes into the can and the other to the intake? If so, then all you are really doing is filtering and nothing more - pressure build up should not be an issue. Are you guys talking about a disconnected system or the one I am describing [and tons of guys here are running] or something else? Please explain. Thanks.
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I think a catch can could cause problems when it is simply vented to the atmosphere as opposed to hooked up in line with the PCV system. When it is hooked up in-line, the only danger it could pose is if it was clogged.
One thing I haven't seen is fresh air positive ventilation (via a slash cut tube in the intake) for the valve covers. The is a good idea on some engines that I'm famililar with (high rpm Hondas), but I haven't seen this done on LS1s.
Also- I've seen some people eager to use the exhaust as a vacuum source for PCV purposes. I've heard this is a bad idea if muffler are used since they cause backpressure. Backpressure will force exhaust gases into the crankcase which is a pretty bad situation.
Ben
One thing I haven't seen is fresh air positive ventilation (via a slash cut tube in the intake) for the valve covers. The is a good idea on some engines that I'm famililar with (high rpm Hondas), but I haven't seen this done on LS1s.
Also- I've seen some people eager to use the exhaust as a vacuum source for PCV purposes. I've heard this is a bad idea if muffler are used since they cause backpressure. Backpressure will force exhaust gases into the crankcase which is a pretty bad situation.
Ben
Originally Posted by RX-Ben
I think a catch can could cause problems when it is simply vented to the atmosphere as opposed to hooked up in line with the PCV system. When it is hooked up in-line, the only danger it could pose is if it was clogged.
One thing I haven't seen is fresh air positive ventilation (via a slash cut tube in the intake) for the valve covers. The is a good idea on some engines that I'm famililar with (high rpm Hondas), but I haven't seen this done on LS1s.
Also- I've seen some people eager to use the exhaust as a vacuum source for PCV purposes. I've heard this is a bad idea if muffler are used since they cause backpressure. Backpressure will force exhaust gases into the crankcase which is a pretty bad situation.
Ben
One thing I haven't seen is fresh air positive ventilation (via a slash cut tube in the intake) for the valve covers. The is a good idea on some engines that I'm famililar with (high rpm Hondas), but I haven't seen this done on LS1s.
Also- I've seen some people eager to use the exhaust as a vacuum source for PCV purposes. I've heard this is a bad idea if muffler are used since they cause backpressure. Backpressure will force exhaust gases into the crankcase which is a pretty bad situation.
Ben
Originally Posted by tdwta2001
that what mine seems it is doing .i put heads on and im getting pressure so great that the oil is coming past the intake towards the maf.i do not understand how to fix this.if i take off the oil cap while the car is running it puffs out.anybodys do this...???
How do your plugs look? Have you done a leak down or compression test?????
no test yet but my car only has 29000 on it i hope it is not piston or rings.this just started after the heads were changed about a month or so now.i was also reading about putting a metco breather in place of the oil cap.so i may try this too.im also going to get the catch can .let me know if you come up with something that works....
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Originally Posted by cyclerage
I am having the same issues. I'm pretty sure I cracked a ring or something, Not ready to pull it apart yet so I'm sill going to play with it for a while. As of now, I have the stock pvc system, but I have taken the front port on the passengerside valve cover (hose use to go the the upper port on the throttle body) and run a hose a catch can. Before this I was blowing oil through the knock sensor ports under the intake. Now it seems to be working fine.
How do your plugs look? Have you done a leak down or compression test?????
How do your plugs look? Have you done a leak down or compression test?????
The port going into the throttle body was my main problem, It seems that port is more crucial then the rear pcv venting ports on an LS1. After I had reconnected the back ports I saw no change. I had a breather on the front port with no change, I plugged it back into the throttle body and all of my crankcase pressure was eliminated. Before you damage you motor I would plug that back into the throttle body as you can easily break a ring from this pressure the more I research this.
Good Luck.
Rob
Originally Posted by Tweakd
The port going into the throttle body was my main problem, It seems that port is more crucial then the rear pcv venting ports on an LS1. After I had reconnected the back ports I saw no change. I had a breather on the front port with no change, I plugged it back into the throttle body and all of my crankcase pressure was eliminated. Before you damage you motor I would plug that back into the throttle body as you can easily break a ring from this pressure the more I research this.
Good Luck.
Rob
Good Luck.
Rob
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Its very possible mine is different. My guess is you have an F-body. I have a Vette, since they are completely different throttle bodies I am just talking out of my *** when it comes to the F-body t/b since I only am learning about my drive by wire bullshit t/b.
Originally Posted by Tweakd
Its very possible mine is different. My guess is you have an F-body. I have a Vette, since they are completely different throttle bodies I am just talking out of my *** when it comes to the F-body t/b since I only am learning about my drive by wire bullshit t/b.
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Then we have the same setup. I had zero pressure after rehooking that up and taking the breather off the from pcv port. The vaccum port on the intake made no difference when I reconnected it. Only the t/b port made a difference. The breather somehow made no attempt to release pressure out. Very confusing to me. I'm guessing it needs vaccum to pull pressure out of the crankcase. The more and more I learn about this the more i want to do the LS6 pcv conversion.
If you have a choo choo train comming out of the oil fill cap while it is idleing with a pvc system inplace you have a piston or ring issue that is allowing the cyclinder presure to fill the crank case etc. And as long as you have a catch can in place between the crank case and the intake there is no issues. Like some one said earlier it is just collecting the oil and still letting the motor pull a vacum like a filter or a knock out pot. A good description is just like what an air dyer does catches all the water before it enters you tools etc. I have no real evidence on the catch can on a motor that is just using breathers I wouldn't think it would be doing squat any way. Good luck.
I'm having a similar problem. at the thunder shootout at the end of one pass my dipstick shot up and sprayed oil all over. the car is stil running great, I just zip tied the dipstick down. guess I need to check my pcv... the engine has less than 500 miles on it and about 10 passes. not down on power at all, burning any oil or blowing any black smoke...
any idea's?? called FMS and TR and they both said it almost had to be a cracked piston or ring
any idea's?? called FMS and TR and they both said it almost had to be a cracked piston or ring
That is what mine turned out to be, but I had four bad pistons and the car still ran good. Look at my pictures in my signiture and you will see the ring glands are destroyed. Good luck!