Oil on Manual Boost Controller (1 Viewer)

[Lumpskie]

So, I am running a Gturbo Grunter at 23psi. Today, I noticed that the turbo sounded a little different, so I decided to check the turbo hoses. When I looked under the hood, I found this:



Do you guys think this is related to blowby because of high boost? Should I be worried? My rig is driving great and I can't see any smoke come out of the back.

Your input would be appreciated!

Thanks,

 

[IanB]

Is that oil originating from within the wastegate hose? Or leaking onto the boost controller from somewhere else?

 

[Lumpskie]

It looked like it was coming out of the boost controller. Running Shell 5w40 T6 this time too. Do you think the thinner oil might make for blowby?

 

[IanB]

I'd start pulling hoses off and making sure I know where the oil is coming from to start with. For oil to be getting pushed up the wastegate reference line it's got to be all in the air coming out the turbo on the way to the intake manifold, it should be pretty easy to confirm the entire intake tract is covered in fresh oil.

If it's a blowby issue the hose off the valve cover to the intake pre-turbo will be the source. Is the hose from the filter housing (post vent hose inlet) to the turbo inlet covered in oil? Is there any oil leaking from the turbo housing? That's where I saw oil on mine before adding a catch can.

 

[Lumpskie]

I couldn't find any evidence of oil coming off the turbo housing. I could see possible evidence of oil on the hose from the crossover pipe here:



Also, my previous picture was from the lower/back side of the MBC. The front side looked like this:



As background, I've had the boost controller on for almost 14,000 miles.

 

[IanB]

What sounded different about your turbo that lead you to investigate? Is there oil at the gaskets where the intake manifold meets the head?

 

[Lumpskie]

Normally, the turbo sound it a crisp "turbine" sound. This morning there was a faint hint of a fan sound with it. It made me wonder if I have a boost leak. When I looked at the boost gauge, it seemed like I was actually making more boost than normal. That made me look at the MBC where I found the oil.

So, the gasket you want me to look at.... the cross over pipe attaches to the intake manifold. At the bottom of the manifold, where it meets the head on the U.S. driver side of the vehicle... is that where I should check? Do you think that this gasket is bad?

 

[IanB]

I've found that my boost level is higher (about 2psi) when it's cold out as well, not sure what to attribute this to, I'll probably re-adjust my MBC to my target boost level. I have the same MBC as you, FWIW.

There are gaskets for each runner of the IM where it meets the head, there was oil leaking down the head on my truck, and I suspect under certain conditions a slight boost leak as well.

 

[Lumpskie]

Talked with Tor just now. He thinks that 23psi on the stock air box is too much and it's creating suction at the intake. He says that he's seen Gturbos blow up because the restriction in the stock intake creates suction and actually pulls the compressor wheel forward. He suggested turning the turbo down to 18psi and getting his air box kit, when it comes out.

 

[MonsterCruiser]

Since you know you are boosting to 23psi I'm guessing you have a boost gauge, have you been seeing higher boost levels? I suspect the MBC may be gummed up with all that oil. I'd take it apart and clean it out.

I've found that my boost level is higher (about 2psi) when it's cold out as well, not sure what to attribute this to, I'll probably re-adjust my MBC to my target boost level. I have the same MBC as you, FWIW.

How cold does it need to be to see higher levels? I wouldn't be surprised if the spring gets stiffer at -10C or less increasing the resistance to move the ball and thus increasing the boost level.

 

[IanB]

Since you know you are boosting to 23psi I'm guessing you have a boost gauge, have you been seeing higher boost levels? I suspect the MBC may be gummed up with all that oil. I'd take it apart and clean it out.

How cold does it need to be to see higher levels? I wouldn't be surprised if the spring gets stiffer at -10C or less increasing the resistance to move the ball and thus increasing the boost level.

I haven't taken any notes so this isn't concrete, but it seems that even around 0C the MBC setting creeps higher, I'd set it to 18psi and saw 20psi the other day.

On another note it seems that the boost required to run down the highway seems to be a few psi higher in the winter than to carry the same speed on the same stretch in the summer. Lots of factors that could affect the 2nd observation, but it's something I noticed last winter. This doesn't make sense to me as the cooler air should be more dense than hot summer air, I'd expect the relationship to be reversed.

I have since replaced the IM gaskets to the head, so I'll be watching to see if the same holds true this year, or if I may have infact had a slight boost leak at those gaskets when they got cold/stiff in the winter, causing the turbo to work harder. Many of the bolts clamping the IM to the head were just finger tight when I dug into them.

 

[Lumpskie]

Since you know you are boosting to 23psi I'm guessing you have a boost gauge, have you been seeing higher boost levels? I suspect the MBC may be gummed up with all that oil. I'd take it apart and clean it out.

I think you are right. It looks like I can hit 25-26psi boost under full throttle now. I'm going to clean it tonight and then set my boost to 18psi when I put it back together.

Are any of you other Gturbo guys running upgraded intake boxes?

 

[Lumpskie]

Found something major.

 

[IanB]

Is that a split hose?

 

[Lumpskie]

Is that a split hose?

Yeah... to the manual boost controller.

 

[IanB]

Yeah... to the manual boost controller.

Ya, that will definitely mess with your MBC settings, doesn't explain the oil though. Good thing you found it! That was likely the sound difference you noticed.

 

[Lumpskie]

Ya, that will definitely mess with your MBC settings, doesn't explain the oil though. Good thing you found it! That was likely the sound difference you noticed.

Yeah. I'm hoping the oil was from the pressure drop from the restrictive stock intake...

What do you think?

 

[mudgudgeon]

I'd say you're heading boost leakage from the split hose.
As for oil, does your rocker cover breather still connect into the air intake?
If yes, vent it to atmosphere, or through a catch can. Then clean out all the intake pipe work.
With oil venting into the intake, it eventually bleeds off at the boost controller , at least in my experience

 

[mudgudgeon]

The split hose will be responsible for change in max boost too

 

[Lumpskie]

I'd say you're heading boost leakage from the split hose.
As for oil, does your rocker cover breather still connect into the air intake?
If yes, vent it to atmosphere, or through a catch can. Then clean out all the intake pipe work.
With oil venting into the intake, it eventually bleeds off at the boost controller , at least in my experience

Yeah, I'm currently running the stock setup where it routes back into the air intake. Can I just pull out that hose and put one of those cheesy cone filters in it's place?