Bkaiser8811

I'm wrestling with the possible options of how to properly vent my crankcase with my setup. The motor is a 2006 5.4 3v with a gt35 turbo. Ive tried check valves, catch cans, plugging the driver's side intake nipple and running a breather on the driver's side valve cover nipple. I've tried putting a check valve in line from the driver's side valve cover to prevent boost from pressurising the crankcase (I know I have a pcv valve under the cover but didn't want to rely on it to keep out 8-10 lbs of boost. These are just some of the methods I've tried. Either way I have quite a bit of blow by and all circumstances either lead to oil being spread throughout my engine bay or suspected improper crankcase ventilation. I also suspect I'm getting high crankcase pressure because my oil return for my turbo I suspect is filling up with oil because I've already blown the seals on my first turbo. Any ideas or prior experience with this particular situation would be greatly appreciated.

Arizona Tumbleweed

I don't have any experience with this but it would seem to me that you will have to disconnect the driver's side PCV hose from the throttle body and plug the hole left in the TB. Seems like the turbo is pressurizing your crankcase through that hose.

Bkaiser8811

The line that your speaking of has the integrated pcv valve under the valve cover. That should keep the boost from back feeding into the valve cover from the manifold. Just to be extra sure that didn't happen I put and extra pcv valve in that line to make sure. I'm thinking about running vacuum lines from each valve cover nipples to a vented catch can and just plugging all the ports in the intake manifold. I'm just concerned about that because my boost/vacuum guage is showing 30"+ of vacuum at idle. What complicates my confusion is that if I take a vacuum reading from my OBD2 data gizmo I'm only showing 13-18" of vacuum at idle. I believe my map sensor is what provides that info to my machine so maybe I'm getting an improper reading from my mechanical guage. What's odd to me is that from my understanding the driver's side intake manifold line sucks in air to vent the crankcase via the valve cover. That would mean that the passenger side line is supposed to supply fresh filtered air. What's confusing me is that my passenger side line is blowing not sucking. This makes no sense when you look at the big picture of using the manifold vacuum as an air pump.

Arizona Tumbleweed

I think you're right. I have it backwards (the airflow). The passenger side needs unhooked and blocked off. Then put that breather back on. I'm thinking it will suck air in through it.

Bkaiser8811

Im going to play around with it......THE TRUCK, this weekend. I basically need to find a way to vent the crankcase as much as possible without creating vacuum issues or feeding boost into the crankcase as well. I'm kinda stuck until my new turbo arrives so I can start her up and see what works best. I also vented my oil fill cap with a breather to hopefully increase ventilation.

Arizona Tumbleweed

If you unhook the passenger side hose and block off the hole in the throttle body I think it will work.

Eric Kleven

Are you sure there's a check valve in the PCV? I thought it was just a restriction and a heater element....

Bkaiser8811

I feel I have the crankcase pressure problem solved with my new vacuum/pcv/evap setup. I have both valve covers ran to a vented catch can with an additional tap in the oil fill cap for extra ventilation also ran to the well vented catch can. I plugged the nipple on the passenger side intake manifold and also plugged the nipple on the driver's side which I use to hookup my vacuum/boost guage to. I installed a new turbo after the first one crapped out after 300 miles (the seller exchanged the first one with a new one for free). I re installed the new turbo (same brand, type) and within 20 miles it was also blowing smoke out of the exhaust and eventually the compressor wheel began to score the housing. Another bad turbo. Both were ran with oil restrictors provided by the manufacturer. They were cheap eBay turbos. I have a 3/4" oil return line which I tested for proper drainage by doing the following. First I parked the truck at a downward angle to allow for the oil In the sump to run towards the point on the front of the pan where I have it tapped for the return. With the second turbo removed I connected the UNRESTRICTED 4AN oil feed line to my 3/4" ID drain line. This scenario would introduce much much more oil to the return line then when the turbo was on and restrictor in place. I fired up the truck from a cold start and read 60 psi at idle which is only 10 psi less than my max psi under load at WOT. The oil return line never backed up under this "worst case scenario". I let the truck run until it reached operating temperature and 15 psi hot oil pressure, about 5 minutes. No oil drain backup. I have concluded that the company I bought these turbos from sell junk turbos. They refunded me the cost of the turbo and now I'm looking to spend a little more money on a better turbo. Im thinking about switching from a journal bearing turbo to a ball bearing turbo instead. Let me know what y'all think.

Eric Kleven

I have to ask, are you running an oil scavenge pump to push the used oil from the turbo back to the engine?

Bkaiser8811

No. My turbo sits about 20"s higher than where the front/top of the oil pan is tapped for the oil return line. My last post IMO showed that I'm not having a return issue due to the "worst case scenario" test I did. If you see any fault in what I did please point it out as I'm open to any ideas. Maybe I should do the same test while revving up the motor to see if I'm getting crankcase pressure that builds while at high RPM keeping the return oil from making it back into the oil pan. It's gonna **** off the neighbors but I'm heading out of town for a week tomorrow anyway....hahaha.