Precision 5858 Turbo Issues
The -10AN Bung is welded onto the pipe. That is why all the powder coat was removed around the welded area. I recoated it later after the testing was all done. It does look like there is sealant there in the pictures though.
- Robert
- Robert
The OP stated: "He told me it must be that the turbo can't drain oil properly or that I have to much crankcase/PCV pressure"
So I was recommending that oil cap device (which seems pretty slick) as an option to relieve all crankcase pressure to make sure he doesn't have a crankcase pressure issue. He can also go back to the turbo seller and say that he has alleviated any possible crankcase pressure issue, since that is what they are standing on currently. It is a cheaper quicker option than changing the PCV setup and doing catch cans, etc. Am I missing something
~Jaraxle
So I was recommending that oil cap device (which seems pretty slick) as an option to relieve all crankcase pressure to make sure he doesn't have a crankcase pressure issue. He can also go back to the turbo seller and say that he has alleviated any possible crankcase pressure issue, since that is what they are standing on currently. It is a cheaper quicker option than changing the PCV setup and doing catch cans, etc. Am I missing something

~Jaraxle
The OP stated: "He told me it must be that the turbo can't drain oil properly or that I have to much crankcase/PCV pressure"
So I was recommending that oil cap device (which seems pretty slick) as an option to relieve all crankcase pressure to make sure he doesn't have a crankcase pressure issue. He can also go back to the turbo seller and say that he has alleviated any possible crankcase pressure issue, since that is what they are standing on currently. It is a cheaper quicker option than changing the PCV setup and doing catch cans, etc. Am I missing something
~Jaraxle
So I was recommending that oil cap device (which seems pretty slick) as an option to relieve all crankcase pressure to make sure he doesn't have a crankcase pressure issue. He can also go back to the turbo seller and say that he has alleviated any possible crankcase pressure issue, since that is what they are standing on currently. It is a cheaper quicker option than changing the PCV setup and doing catch cans, etc. Am I missing something

~Jaraxle
Open vent isn't enough. Needed something to suck the crankcase pressure out (like stock). I am running 2 open -10AN vents currently and its not enough under normal driving (vacuum). Under boost the open vents seem to work better. The system I posted WITH that oil cap breather would probably be the ideal setup.
- Robert
Open vent isn't enough. Needed something to suck the crankcase pressure out (like stock). I am running 2 open -10AN vents currently and its not enough under normal driving (vacuum). Under boost the open vents seem to work better. The system I posted WITH that oil cap breather would probably be the ideal setup. 
- Robert
- Robert
I wouldn't run that VTA cap with a recirculated setup. I would make it impossible the recirc vents to draw a vacuum in the crank case (which is the goal). Once the crank case got to 0psi, or close to it, the other vents will just start drawing air through that breather. And it in boost, it will be a source of unmetered air if the car is running the MAF. And when the throttle is closed, it will be like a post throttle body vacuum leak, making idle harder to control.
"This breather is the ONLY one in the market which incorporates a check ball to keep unmetered air from coming through while the crankcase is under vacuum. In other words, this breather acts just like a factory oil cap under normal driving conditions and when you get into boost it will release any crankcase pressure present."
- Robert
- Robert
"This breather is the ONLY one in the market which incorporates a check ball to keep unmetered air from coming through while the crankcase is under vacuum. In other words, this breather acts just like a factory oil cap under normal driving conditions and when you get into boost it will release any crankcase pressure present."
- Robert
- Robert
The check ball/valve addresses that. It only releases any pressure that may be in the crank case, it does not allow air to enter the crank case.
"This breather is the ONLY one in the market which incorporates a check ball to keep unmetered air from coming through while the crankcase is under vacuum. In other words, this breather acts just like a factory oil cap under normal driving conditions and when you get into boost it will release any crankcase pressure present."
- Robert
- Robert
Cool. I didn't read into the description much.
Now that we all understand what that CFM cap does, wouldn't this be cheap and quick to TRY and relieve MORE pressure under boost? It closes under vac and therefore won't mess with PCV or idle. No it doesn't PULL, but honestly I am doubting the stock does much honestly. It will only relieve the problem more, and compliment any PCV/catchcan setup installed or being installed. I say throw it at the problem cause it cannot hurt, and only help.
~Jaraxle
~Jaraxle
There should be nothing but vacuum at that time.
OP: Can you re-route your boost gauge to a hole drilled in your oil cap (and then buy a new oil cap)? I want data that says you have crank-case pressure under vacuum/decel.
~Jaraxle








