oil bubbling during boost test

[6boltSpyder]

Does anyone who why this would happen? I put a boost tester on the turbo to see if the intercooler piping was leaking at all and my oil in the engine started to bubble. Does any one who whats up? thanks Jon

 

[staticbrainwash]

sounds like you might have bad valve seals or bad piston rings.

either way you've got air entering your crankcase. have you have problems leaking oil out of your oil cap or you dipstick popping out? those are also pretty solid crankcase vent problems.

 

[Corman12345]

It has nothing to do with the engine itself. What is happening is air is leaking past the bearings/seals in your turbo and is blowing down the oil outlet tube that leads to the bottom of the pan. The bubbling sound is from the air bubbling up through the oil from the bottom of the pan. mine did this too with the old worn out t25. It quit once i put my new turbo in.

How many miles is on the turbo, probably a lot huh?

 

[Staytuned]

My brand new 3052 does it also. That's why they don't suggest doing a pressure test on the GT30 center housing.

 

[Defiant]

How much pressure are you people using? You're suppose to run about 20psi max.

 

[ddavisaf]

PM sent, post back here.

-subscribed

 

[ddavisaf]

I'll post here what I replied over PM.

If you're testing from the turbo inlet, bubbling oil is normal. During a static test air will get past the seal and down into the turbine inlet. If you're testing from the turbo inlet try testing from the LICP and see if your results change.
If you ARE testing from the LICP...
How is your pcv routed? Is it normal and back to the intake manifold? Or is it routed to a catch can?
Try disconnecting the pcv from the intake manifold and plugging the hole and re-test. See if your results change. If they do, replace the pcv with a good OEM pcv. Test them while you're there buying one by blowing through the straight fitting end of the valve. If you cannot blow any air through the straight fitting, and you can blow air through the treaded side, buy that valve.
If you still hear the bubbling with the pcv disconnected and the manny capped. Run a compression test.
Post back your results.

 

[6boltSpyder]

Yea i dont think its the rings because the motor runs fine and even under boost i dont loose pressure. Im running a garrett t3t4 not a stock turbo and it has no shift play. not too many miles on maybe a 1000. Ill check out everything else tonight and let you know, thanks for the help

 

[Staytuned]

How much pressure are you people using? You're suppose to run about 20psi max.

First time I tried it it started to bubble in the crankcase around 10 psi. I haven't done it since from the turbo inlet since getting advice from FP.

 

[daren_p]

How much pressure are you people using? You're suppose to run about 20psi max.

This may sound dumb but aren't you supposed to use as much pressure as you normally boost? Obviously if your runnin 16psi or something then you don't need any higher then 20psi, but what if your running 25psi you should test to that pressure level correct? If you don't put in as much pressure as you are running boost you don't know if you have leaks or not.

 

[Staytuned]

If you can hold 15-20 psi with no leaks that's pretty sufficient. No need for 25-30 psi of static pressure.

 

[Liger]

Sounds interesting. I have a similar problem in that when i do a pressure test on the inlet of the turbo, i lose a lot of pressure through my exhaust? I have my compressor putting out 45-55 psi and my gauge is reading 15 on my car and i can hear the air coming out of the exhaust but there isn't any other leaks in the system. Turbo is in great condition, like 5k on it, timed every time, no shaft play and doesn't burn oil. I dont get it. Brandon [VFRacing]

 

[ddavisaf]

If you're hearing air coming out of your exhaust, then it means you've got an issue. Your PCV may be bad, your piston rings, or valve guides/seals. Run a compression test...

Your test should be at 20 psi, and you should hold 20 psi for a minimum of 30 seconds. That is a perfect boost leak test. If your car is setup to run 25+ psi, run a test with 30 psi.

 

[95AWD_TSI_TALON]

Most larger turbo have this problem....as in if it hasn't been ran in a day or so the seal wont be 100% sealed and air will bypass through the oil seal in the turbo. I has the same issue with my old 60-1 once.....I called Ben at AGP expecting to get a rebuild. ALl he told me was to start it up and shut it down 2 mins later, didn't do it ever again.

As for the issue of the air leaking through the exhaust- pinch your wastegate line, I don't know for sure if internal wastegate's have this issue but I have always had that issue on stock motor and 6 bolt motor with my external set-up.

If your running 25+ psi you don't need to pressure your system up that high...going that high will only tell you if your IC piping will blow off or not. All you need to go is 20psi and see how SLOW it comes back down to 0. I have had mine take over 2 mins to bleed back down to 0 from 25.
Matthew

 

[6boltSpyder]

Ok I have come to the conclusion that it is leaking past the seal and going down the oil return line and bubbling in the oil tank. So i checked to see if the turbo was blowing oil and its not. So from now on im just gonna check it fron the intercooler pipe commin off the turbo. Thanks for the help guys!!!! Jon

 

[Liger]

I dont see how pinking the wastegate vac line with do anything for an internally gated turbo since the diaphram is not directly linked into the exhaust like on an externally gated turbo. I am thinking that it is bad valve seats possibly. I did a compression test a month back and got 165 150 165 165. So i think cyl 2 has a seating problem caused by severe fuel richness caused by a "company" screwing up my injectors numerous times after i sent them back and had them "fixed" but anyways. It has not gotten any worse..so i dunno what to think? Most of the air is leaking out of my pressure tester , but i can still hear a faint amount of air coming from the exhaust. I will check my pcv valve and make sure it is working properly. Brandon [VFRacing]