New 408 issues
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Teching In
Joined: Jul 2010
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New 408 issues Iv got a weird problem on my 408. At idle it has steam or smoke coming out of the oil fi cap. This is happing when i have my pcv hooked up i have the ls6 vally plate and fresh air side hooked up. When i take the oil fill cap off the steam or smoke comes out but when i rev the motor up it stops coming out untill it goes back to idle. Now if i hook up the manifold vacuum to the passengr side valve cover and vent the driver side it wont let any of this steam or smoke come out. What i dont under stand is why if im pulling from the ls6 vally plate is why it will still smoke but not if i pull from the valve cover the motor only has about 2000 miles on it. Its got lynatie crank and rods with weisco flat tops wih steel top ring napier 2nd ring. It dosent eat or use oil. And its not down on power. It didnt do this untill after i got the air fuel tuned befor that it was running off of my h.c.i tune with my 36# injectors i didnt beat on it till i got the new bigger injectors and a good tune it i only drove it hard enough to seat the rings and such. Im not using synthetic oil. My ring gaps are set at 20top 22bottom. Maybe my rings just still havnt fully seated yet. Any ideas or suggestions would help. Oh and i have not done a compression check or leak down test yet i will if i have to.
On The Tree
Joined: Sep 2008
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From: Virgina Beach
Where are you from? Steam tells me it's water. Most likely condensation burning off. All my motors have done it too until they've warmed up all the way and burned everything off. Happens most with cars that aren't driven everyday or racecars. They have time to build up a lot of condensation. And what part of the country you live in will lend to it sometimes.
Thread Starter
Teching In
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I live in oklahoma it has been kinda cold here but even after the motor is up to temp it still steams or smokes. I have my manifold vac pulling ony ls6 vally plate and the fresh air side is hooked up to the throttle body. If i hooke my manifold vaccum up to the valve cover and cap off the vally plate the steam/smoke stuff stops coming out of the oil fill tube but if i hoomed it up to the vally plate it smokes again. Im stumpd.
Thread Starter
Teching In
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Im really starting to think that this motor being 11.5.1 compression and still new. It prolly hasnt broken in all the way yet. I did the moto ring break in took it up from 2k to 5k for 6-10secs and just varying the rpms for the first 20 miles then chaged the oil and i changed the oil again at 50miles then again at 300 im still on the 300 mile.oil which i will be chamging this wknd. The motor has 2500 on it i went and look at my od to check
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im really wondering if you got a lot of crankcase pressure and the oil vapor escaping from the easiest spot thats open (your filler cap) is venting there. no clue, but been seeing a lot of pcv/crankcase pressure/oil seepage threads lately
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Teching In
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I called texas speed today and told about what was going on and they said that im prolly gona have to just and breather filters to valve covers they said it dosent sound like the motor is hurt or the rings but like tou said just alot of crank pressure. I really dont know this is my first stroker motor. My ls1 that this 408 is replaced did have blow by really bad cause when you gave it gas more vaper would push out of the oil fill neck so atleast i know its not that kind of problem. It just sucks lol go to pop the hood and have to be like o all that vaper its not bad its just to much pressure
Well heres what I recommend you do. Get two of those mini air filters, easiky found at auto zone etc. Youre gonna need a crossover tube to connect both valve covers and install one of those filters on each cover. Run a catch can as well
Mine will smoke out the catch can when the oil has a little water in it from being wet or cold out. Dads car has to have the catch can drained about once a month. He drives it every day. Always water leakdown is 1-2% so it is not a rind seal issue.
I would not worry about it.
Tim
I would not worry about it.
Tim
It seems to be working flawlessly. The only thing I do is drain the catch can about 1 a month. I have it on 14" at wot. I'm not sure how much power it adds. I need to do some dyno pulls without the belt. Last dyno did 582/520. So its gotta be helping.
I know I've ran the car at idle with it undone and it puffs oil condensate out the oil cap and dipstick , but with the pump running no condensate out of either. I'm happy with it. It can only extend the life of my motor. Its a Win/win situation !
I know I've ran the car at idle with it undone and it puffs oil condensate out the oil cap and dipstick , but with the pump running no condensate out of either. I'm happy with it. It can only extend the life of my motor. Its a Win/win situation !
Thread Starter
Teching In
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Well it makes it alil better knowing im not the only one that this is happing to. Im goin to do a compression check today i would do a leak down test to but i dont have the tester for that i guess if the compression check comes back good ill start saving for the vacuum pump from gz. Hopefully theres nothing wrong. I mean i took my time and measured everything out while putting it together it would be a downer if i did somthing wrong this is my first motor i ever built.
The vacuum pump will help with your crankcase pressure and keep oil from pushing out of places like pushing the dipstick out and puking at WOT.
So how hard was it to do the gz pump? Ive got a 240sx so space is a factor so where did yours mount to?
So how hard was it to do the gz pump? Ive got a 240sx so space is a factor so where did yours mount to?