Help! Oil leak at hotpipe/wastegate
I'm getting oil spray and residue out the hotpipe to wastegate band.
Oil pressure at idle is 55psi. I bought some vibrant restrictors for the feed line 3an, but I don't think that explains oil in the uppipe...could there be a motor problem with blowby?
Any other ideas or alternatives?
When you look down in the exhaust manifold there is a puddle of thick black oil sitting in the manifold! This oil is supposed to be brand new with 0.1 miles.......what is going on?
As for the location, I'd suggest you check the turbine hsg, and see if the oil is running back down into the manifold.
If not, only a couple other sources it can come from.
1.valve guides.
2. rings....crankcase back psi...stock pcv fail.
Trending Topics
I'm getting oil spray and residue out the hotpipe to wastegate band.
Oil pressure at idle is 55psi. I bought some vibrant restrictors for the feed line 3an, but I don't think that explains oil in the uppipe...could there be a motor problem with blowby?
55psi oil pressure at idle is a lot, how much is it at higher rpm ?
What is your oil drain like ?
Crankcase breathers ?
The Best V8 Stories One Small Block at Time
Stevie,
It's a brand new setup, no drives yet. Only fired up ling enough to detect the problem.
Yes 55psi at idle with Thompson ls3 and their melling pump. It's still on the gmpp 525 ecu tune so no higher rpms than idle yet, it stumbles with throttle. Was hoping to get it idling, up to temp to check out all the systems then head to the tuner for a baseline tune to get the 500mile breaking going.
Oil drains are as prescribed by comp 1/2in to 45 degree 10an fittings straight down in pan.
Currently the pvc is setup similar to stock ls3 with stock valve covers. Driver valve cover tied to driver turbo intake, passenger valve cover tied into intake just behind TB.
I have a set of fabbed sheet metal covers and was considering pushing a trick flow valve breather 1 inch opening in each cover?
What size feed lines to the turbos ?
1/2" drain sounds small if that's what you are saying ?
You could try removing the oil filler cap to see if it changes, as that would definitely give the crankcase adequate breathing if the current setup does not
BB or oil journal ?
Mine is -4 tee'd to equal length -3an lines to each turbo.
Thanks, I'll try the filler cap idea too. Won't that make a serious mess?
A lot of BB turbos only need a tiny tiny amount of oil. Most these days have a restrictor built into the oil feed on the core, but some dont. This can be less than 1mm sometimes.
But removing the filler cap will test the crankcase breathing aspect. If the oil smoke clears up after running with the cap off for a while, then your crankcase breathing system is inadequate.
Really there are only 3 universal things that cause the turbo to burn or pass oil.
1 Inadequate oil drain
2 Blocked crankcase breathers, which essentially prevent the oil from draining correctly from the turbo so is almost same as 1
3 Excessive oil supply/pressure.
Cleaned out hotside, inserted restrictor to -3 feed, found very slight kink in 5/8in ID drain tube (corrected), restarted.
It appeared as though the oil was going to burn off and disappear but after 1min the smoking began to increase and the oil start droping out the down pipe at the firewall.
I remove the wastegate and turbo. The turbine was saturated, up pipe saturated to the first primary but the rest of manifold clean. I now believe ive confirmed the turbo is leaking and its not the motor.
Pulled the turbine of the turbo, turbine is saturated. Im a newbie to turbos but was expecting a gasket to be smashed between the turbine and center cartidge...there is not... so I'm not sure what/how to inspect the assembly
After a long talk with Comp-
1) they don't like vibrant's restrictors and had me purchase their smaller 0.018 filtered restrictors
2) they'd rather me run a distribution block at the motor and two separate -3 lines all the way to the to the turbo. They also recommended running 3an all the way instead of starting with 4an...which I had already done and replaced with the 4an due to someone's recommendation there.
Experience is what it is...but I don't understand a few things...if it's a volume/pressure issue, then why wouldn't the passenger side have started leaking after I added a restrictors to the driver's. Wouldn't the pressure have followed the path of least resistance and blown the passenger side? Also, what difference would it make to tee the feeds off at a distribution block at the motor vs teeing them off my 4an line?
So, I'm going to wait for the new restrictors....and we'll see.
Hell, I have a -8 takeoff from my remote oil filter, through a check valve then tee into a pair of -6 lines to each turbo.
I did chicken out with the -6 and reduced it to -4 at the turbo inlet though even though turbo supplier said to keep a full -6 to each turbo ( BW )
Once I got the scavenge setup working, no issues at all with oil control.
Turbo oiling is very very simple. They basically rely on the drain always getting rid of more oil than you can pump in. There are oil slingers that rely on the rotation of the shaft to keep oil away from either turbine or compressor side.
The "seal" people talk about is a piston ring design, and intended to keep either boost pressure or turbine pressure out of the core, it is not an oil seal.
Well covered here
http://www.yellowbullet.com/forum/sh...618&highlight=
While waiting on the restrictors from comp I began working on other things. This lead to an inspection of my ls3 intake which has a big puddle of oil in the back 1/3 (it's sitting back 3 degrees). Keep in mind the entire hotside is clean and only the intake manifold and driver's hotside is wet.
So...I'm going to remove and clean the intake mamifold, remove and inspect the plugs, remove the valve covers and look for damage.
Any other suggestions?
Last edited by nlpy8b; Feb 18, 2016 at 08:33 PM.
Motor is a Thompson stocked ls3.
Valley plate is l92 with no valley port.
Passenger valve cover is tied to I take manifold just under the MAP sensor.
Driver's valve cover is ran with hardline up to the driver's side turbo intake.






