VF28 without engine management

That spinning thing that makes all of the cool noises. OE and Aftermarket.

Moderators: Helpinators, Moderators

86BRATMAN
Second Gear
Posts: 415
Joined: Sun Mar 04, 2007 4:59 am
Location: Tazewell VA

Re: VF28 without engine management

Post by 86BRATMAN »

Are you running oem oil feed and banjo bolts or one of the braided line kits out there?
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I am running a new braided line from a Kinugawa kit. It was first installed on the TD04 and then reused on this turbo. The TD04 turbo lasted just over a month.

Pulled the bolt off the top and all is good with that. Didn't pull the bottom bolt yet as it is freezing outside. From first install, I am pretty sure it is all good based on the oil the line spewed when not tightened properly at the top joint..

This is the banjo bolt that came with the kit (TD04):

Image


Do I need something with a larger opening like this:

Image
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
86BRATMAN
Second Gear
Posts: 415
Joined: Sun Mar 04, 2007 4:59 am
Location: Tazewell VA

Re: VF28 without engine management

Post by 86BRATMAN »

Honestly I'm thinking what you have is too big, allowing too much oil pressure through the turbo and blowing the seals. If the turbos had failed in different ways I wouldn't think this. But you've got 2 turbos in a row that did the same thing. Both with that feed kit in common. From what I've seen the oil seals in a turbo aren't like your typical cam or main seal, but more like a piston ring (in fact most turbo rebuilders refer to them as piston rings). I highly recommend you source (or reuse) a factory oil feed line and banjo bolts before installing another turbo.
cj91legss
Fifth Gear
Posts: 6317
Joined: Fri Jun 20, 2008 8:17 am
Location: Lakewood, Wa 98439
Contact:

Re: VF28 without engine management

Post by cj91legss »

I have the same feed line, and mine worked out great. I may have to get a new one tho, since I have a ball bearing turbo going in my build.
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

Here is the banjo bolt feed into the turbo for the stock line. It definitely does look quite a bit smaller than the Kinugawa.:

Image

Is there any way I could be building more oil pressure than what is needed through the line? Is there an independent oil feed ''pump" for the turbo from the pan?

The other thing I wonder about is the pcv system. The rear breather on the block is now routed 90 out under my intercooler to "F" pipe and then run to intake and pcv. Could this at all be creating increased pressure? I thought I stumbled upon something saying increased crankcase pressure can cause problems with the turbo.

All in all, the cat is definitely getting replaced as it has been suspect. That will be step one for sure.

Thanks for your replies guys. I appreciate the insight. Will be interesting to hear more about the oil feed.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
Legacy777
Site Admin
Site Admin
Posts: 27750
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: VF28 without engine management

Post by Legacy777 »

Like the others have mentioned I really suspect an oil flow issue, and you getting too much flow to the turbo. If you find a local turbo rebuilder it may be worth asking them about this. They may be knowledgeable and be able to provide you some feedback.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I just thought of this and I am going to throw this out there. I recently switched to the Rotella T6 5W 40 oil. It seems that my turbo blow outs all have occurred after that switch. Any way that this could be causing a higher pressure and creating problems with my turbo seals?

That seems to be a possibility on where the extra pressure is coming in. I will stop into the local Sube shop tomorrow and ask as well. I am interested in what you all think about the oil weight as a possible cause.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
James614
Fourth Gear
Posts: 1744
Joined: Sun Jun 10, 2007 4:35 am
Location: Arkansas

Re: VF28 without engine management

Post by James614 »

5W-40 is within the factory recommended weight range and that specific brand/type is commonly used in the Subaru community.
93 Touring Wagon (EJ20G 5spd Swap) -- Finally back and running strong as ever!

05 Outback 2.5XT 5spd -- Now the wife can have her SUV and get in on the turbo Legacy goodness at the same time.
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I started using T6 based on feedback from the local community here. I figured as much but also figured I'd throw it out there. Never know what might be a solution.

All I do know at this point is that the busted and rusted doesn't make a very pretty lawn ornament!
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I talked to the local shop and they gave me two variables to check.

One is the oil drain. Make sure it doesn't have build up or is obstructed into the cylinder head as it could back up and blow the seals.

The other was the oil feed line diameter. They said that if the line has doubled in size that the pressure would be significantly more and cause the increased pressure. They recommended putting the stock line on.

Not sure when I can get around to this but I am hoping Friday.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
RoughDiamond
First Gear
Posts: 121
Joined: Fri Dec 19, 2014 8:39 am
Location: Akron, OH

Re: VF28 without engine management

Post by RoughDiamond »

:smt021 First, as you increase pipe diameter, you get decreased line pressure but more flow (using some basic assumptions here, of course) purely based on fluid dynamics. FHI and IHI thought it necessary to use a TINY hole in the banjo bolt and a considerably smaller banjo bolt than the head side. I assume this was to restrict oil flow as not to starve the head and oil galley and also to prevent the bushings from being GUSHED and overpressurized with oil.

However, I DO think it's a flow-based problem. It's recommended in some engine building communities to avoid high pressure, High-Flow (High Volume) oil pumps because at lower engine speeds, it can actually starve the bearings due to the sheer volume of oil, it actually acts like a fire hose instead of bathing the bearing in oil.

I think you've got the same problem here with the turbo. Those passages are not meant to be pressurized and forced fed with oil. It's essentially a bearing "bath" setup and the piston seals are the only thing that can handle the heat and rotating speeds of the turbine shaft. Too high of pressure for the turbo bearings and too much flow will starve the bearings, blow out the seals and just lower the system pressure overall.
1991 Legacy SS (BC) EJ22T // 4EAT // Pewter Metallic (Sold)
1991 Legacy SS (BC) EJ22T // 5MT // Rio Red (Sold)

1991 Legacy SSRS (BC) EJ20G (Full COP and AWIC Swap) // 5MT // White Pearl Tri-Coat Africa Rally replica in progress.
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

With that said, are you thinking that using a larger line with decreased pressure and finding a banjo bolt with a smaller opening to feed the turbo would be the way to go? Decreased pressure and flow? (I am not versed in fluid dynamics)

I agree that the feed into the stock line is massive compared to the opening in the banjo bolt feeding the turbo. What is the point of creating such a large supply of oil to that small hole on the banjo bolt in the fluid dynamic world?

My main question is about the different pressures that these first gens run (45 psi @ 5000) on a VF11 and the last two turbos I have installed that run stock pressure on WRX and STI between 70 and 100 psi at WOT regularly. That seems to point to a crazy amount of pressure being built up in these turbos on a system that normally runs well below the pressure they were ever intended to run with. If I put the stock line back on wouldn't it be safe to assume I would only peak out around 45 psi, which is a safe pressure? Something has to be building the pressure and there doesn't seem to be many options for doing this.

Just trying to wrap my head around this. It seems there is an easy answer somewhere.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

Pulled the intake off today and found this :shock:
Wish I could say it is just a little bit of oil.

Image
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I ended up switching my oil line to the stock line/banjo bolt. I have read a few places that you can't "blow" a turbo's seals. This goes right along with what Bratman had stated earlier (not that I was doubting). With this reading, I found a post stating that running trial and error would work in correcting an oil leak within the turbo. Whereas, if I am able to find the right size restrictor the turbo will seal properly and the oil leak will quit. What better way to find out than running it? Sooo, I ran the stock line and found it to smoke a ton at low RPM and not as heavily at higher speeds. Boost levels still held on the turbo. Possibly meaning that higher rpm kept the exhaust pressure high enough to counter the oil pressure??

I ran it long enough to account for burn off. If the stock line would have corrected the issue I would have gone far enough to lose the burnt oil issue and see a corrective state.

This leaves me now with two possibilities. Either it is a drainage problem out of the turbo or I need a restrictor in my line. Once I have results I will post up. If the problem is not here, then I will move on to my pcv system as possible culprit.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
Alphius
Fourth Gear
Posts: 1204
Joined: Mon Aug 31, 2009 9:09 pm
Location: Rochester, WA

Re: VF28 without engine management

Post by Alphius »

Turbo seals are more sensitive to flow than to pressure. Hence the restriction in the OEM feed banjo and the large, open drain. If your drain is backing up it could cause this issue. As your research showed, usually when the condition causing turbo seal overrun is corrected it should correct the leaking as well. The turbo isn't usually permanently damaged.

Plenty of people run newer Subaru turbos (TD04, VF39, etc) on the old lower pressure oiling systems with no problems. I think your comparison of newage WRX/STI oil pressure and ej22t oil pressure is a red herring.

In regards to your PCV system, are your PCV hoses completely oil soaked on the inside? How is your intake tract pre-turbo and post-PCV reintroduction? If you had either a bad PCV valve or a lot of blowby you might be pressurizing your crankcase and simply burning a ton of oil.
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I was definitely confused about the pressure and how it related. Seemed odd that the lower pressure system would cause failure in a turbo that was designed and put on one of the newer, higher pressure vehicles. It finally came together when the volume of the oil was pointed out as the culprit in a few threads.

The other mistake I made was assuming the VF11 was a ball bearing turbo. That would explain why after using the stock line I was still getting an overload of oil going to this turbo. I ordered up the correct banjo bolt for the VF28 through Subaru. I would have bought the original line from the version 5 sti but they will not fit. Hopefully just the bolt will do the trick.

Everything seemed pretty normal pre-turbo where pcv came in. Not excessively wet or anything in the intake besides what you see in the photo and there was no oil trail. I just replaced the pcv valve a month or so ago. More than likely isn't the case but something to consider.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
bcmaxx
First Gear
Posts: 218
Joined: Wed Oct 24, 2012 6:30 pm

Re: VF28 without engine management

Post by bcmaxx »

is it intercooled? my piston/ring let go , and it was pumping a liter of oil in 18km into the intake.....from the pcv system. well anyways, the intercooler holds a ton of oil for a longtime. I just cleaned mine all out this morning, it was nasty. no knock, piston slap or anything heard, just constant smoke that was worse under boost. does smoke come out of the crankcase with the oil cap off after a drive?
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I haven't checked that out yet but will after the next run. It has been intermittent oil burning and goes away after each turbo swap. I definitely should clean out my intercooler. I have done gravity drains on it but should take care of it. I have read some people used gas, diesel and soap and water as options.

If I can't get the problem settled with the oil feed to the turbo I will try a compression test next. Thanks for the heads up!
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
bcmaxx
First Gear
Posts: 218
Joined: Wed Oct 24, 2012 6:30 pm

Re: VF28 without engine management

Post by bcmaxx »

just-rust wrote:I haven't checked that out yet but will after the next run. It has been intermittent oil burning and goes away after each turbo swap. I definitely should clean out my intercooler. I have done gravity drains on it but should take care of it. I have read some people used gas, diesel and soap and water as options.

If I can't get the problem settled with the oil feed to the turbo I will try a compression test next. Thanks for the heads up!
I flushed mine out with brake clean . 1 liter each time . Three times. After gravity drain. And ill letit sit for a few days in the warm to fully evaporate
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

Don't worry guys. I found the rest of my missing oil! Pulled the intercooler for cleaning tonight and found this:

Image
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
mike-tracy
Moderator
Moderator
Posts: 4986
Joined: Tue Aug 25, 2009 7:52 am
Location: Des Moines, Wa

Re: VF28 without engine management

Post by mike-tracy »

Jeebus!
1992 Legacy SS 5mt, build in progress
Josh Colombo wrote: Mon Jan 14, 2002 10:23 am Wait....I'm confused now.
cj91legss
Fifth Gear
Posts: 6317
Joined: Fri Jun 20, 2008 8:17 am
Location: Lakewood, Wa 98439
Contact:

Re: VF28 without engine management

Post by cj91legss »

Nice!!!

It's always good to have lubricated cylinder walls!
91 L-TW Wagon with a full Swap -RIP
92 SS Prefaced, GD dash swapped, 22T/205 Hybrid 20 psi - BEAST!
93 SS Bone Stock Gone!
94 TW Bone Stock Gone!
91 SS 4EAT Sold!
98 LGT 4EAT
98 LGT Wagon 4EAT
bcmaxx
First Gear
Posts: 218
Joined: Wed Oct 24, 2012 6:30 pm

Re: VF28 without engine management

Post by bcmaxx »

just-rust wrote:Don't worry guys. I found the rest of my missing oil! Pulled the intercooler for cleaning tonight and found this:

Image
To the tee what mine did.
just-rust
First Gear
Posts: 230
Joined: Thu Dec 26, 2013 4:22 pm
Location: Minnesnowda

Re: VF28 without engine management

Post by just-rust »

I have enough lube for a few more cylinders! lol

If it is a ring I am SOL. Not sure how I would go about getting that fixed. Old Legacy would have to retire for a while.

Should I skip pulling the turbo and go straight to a compression test? Seems to make the most sense at this point. The only confusion I have is the point at which I put a different turbo in I quit burning oil for a while. A month one time and this time about 12 days. The pulled turbos I have show signs of oil leakage as well.

This is by far the most oil I have seen out of the last three episodes.
Rusty 1991 EJ22T - VF28 - '07 wrx TMIC - MBC - Invidia DP - Walbro 255 SOLD
1992 Legacy SS 5mt, with some neat stuff on it
bcmaxx
First Gear
Posts: 218
Joined: Wed Oct 24, 2012 6:30 pm

Re: VF28 without engine management

Post by bcmaxx »

If you have access to a compression tester i would try that first. Its easy on these. Well eSier than others
Post Reply