Turbo oil return pipe leak

Pete_89T2 · 04-17-2011, 07:08 PM

Figures, less than 2 weeks to DGRR '11, and I find this. It's on my S5 T2, brand new BNR stage 1 turbo rebuild, but with the old stock return pipe. Leak is a tiny one, and apparently due to a corrosion induced pinhole leak where the elbow joins up with the flange, on the turbo side. It's definitly coming from there, and not the gasket or anywhere else.

Questions:

1. Anyone have a good oil return pipe for an S5 T2 they want to sell?

2. What kind of oil pressure & oil flow volume do these oil return lines typically see? This pinhole leak is really tiny; the car has to be running for a long time before a bead of oil even starts to ooze out. In the event I can't fix this before the DGRR trip, I was wondering how much of a risk it would be assuming I carry a plentiful supply of Castrol and check the oil often. DGRR trip will be close to 2K miles round trip, including all the driving in/around the area.

Ender · 04-17-2011, 08:49 PM

Is this the hard line on the top of the turbo? If so that's actually the supply, and that's a fairly common issue whenever the turbo gets pulled/reinstalled. I think it tends to have more to do with the strain on the line where it meets the flange, but regardless a flex line ought to work better. I had mine go out during a track day, started a small engine fire. Sucked.

I recommend making a flex line with a new flange. I bookmarked this flange a while back (so hopefully it'll fit), eventually I'm going to make mine a little more professionally, right now the flange is a hand tapped piece of steel. I also used and would recommend anodized fittings and a braided steel line.
http://www.atpturbo.com/mm5/merchant..._Code=ATP-FTG1

HOWEVER, if you're really talking about the lower oil line (the larger of the two) then I imagine you could do about the same thing with stainless flex line... or find another one. The return line shouldn't see much pressure, idk how much but I think it's basically a gravity feed back into the front of the block.

RETed · 04-17-2011, 09:51 PM

If it is the oil return pipe, there is very little pressure in there.
Or, it should not have any pressure in there...
If there is pressure, the turbo will start to smoke in a very short time.

When you installed the gasket, did you RTV the entire gasket?
This will help in sealing.

-Ted

Garfinkles Motor Works · 04-18-2011, 03:54 AM

Can I braze the area around the flange ? Cheep and easy .I do make flanges for oil lines for 3rd gens but time is not on your side .

Pete_89T2 · 04-18-2011, 07:37 AM

Yeah, it's definitely the oil return pipe (bottom of turbo). Gaskets were RTV'ed on assembly. I know it's not leaking from the gasket by inspecting it, here's why. The stock return pipe on the S5 turbo (turbo side) is basically a flange with an elbow pipe brazed/welded into it; there is also a sheet metal piece that sort of shields the OUTSIDE surface of the elbow, which is attached to the flange, probably brazed/welded as well to the outside of the flange (as it doesn't come off). My oil leak can only be seen right at the low spot at the bottom of the elbow, in the space BETWEEN the elbow and the sheet metal shield piece if that makes sense. No oil is seen anywhere on the outside of the flange, or the outside surface of the metal shield piece, the turbo or from places above (i.e., oil inlet line). So the leak has to be coming from the brazed joint where the elbow pipe enters the flange.

I like Garfinkle's idea of fixing it, but not sure if that's do-able with that shield piece in the way? Might just be easier (and maybe cheaper than a new Mazda part) to fab up some flanges and use properly sized AN line/fittings.

Since it sounds like this leak isn't likely to become a gusher, do you guys agree I can press on to DGRR and deal with it when I return if necessary?

Garfinkles Motor Works · 04-18-2011, 08:03 PM

Pull off the pipe and overnight it to me. or get a new one if the price is good .

FerociousP · 04-18-2011, 09:51 PM

Quote:

Originally Posted by Pete_89T2

Yeah, it's definitely the oil return pipe (bottom of turbo). Gaskets were RTV'ed on assembly. I know it's not leaking from the gasket by inspecting it, here's why. The stock return pipe on the S5 turbo (turbo side) is basically a flange with an elbow pipe brazed/welded into it; there is also a sheet metal piece that sort of shields the OUTSIDE surface of the elbow, which is attached to the flange, probably brazed/welded as well to the outside of the flange (as it doesn't come off). My oil leak can only be seen right at the low spot at the bottom of the elbow, in the space BETWEEN the elbow and the sheet metal shield piece if that makes sense. No oil is seen anywhere on the outside of the flange, or the outside surface of the metal shield piece, the turbo or from places above (i.e., oil inlet line). So the leak has to be coming from the brazed joint where the elbow pipe enters the flange.

I like Garfinkle's idea of fixing it, but not sure if that's do-able with that shield piece in the way? Might just be easier (and maybe cheaper than a new Mazda part) to fab up some flanges and use properly sized AN line/fittings.

Since it sounds like this leak isn't likely to become a gusher, do you guys agree I can press on to DGRR and deal with it when I return if necessary?

Take the line off and either braze it or JB it for the gap... I'd rather have JB on a pinhole (on the return) than nothing at all.

Garfinkles Motor Works · 04-19-2011, 07:42 AM

What if the damage is on the inside and compleatly around the pipe and only a small leak has developed at this time but the rupture is waiting to gush oil .I do not risk failure of a part that I can fix .

Pete_89T2 · 04-19-2011, 09:01 AM

Well I just checked with Ray Crowe at Malloy Mazda on the price of a new pipe - turns out this part is out of production and there isn't a single one left anywhere in Mazda's inventory. So price is a moot point and a repair of the existing part or fabbing up custom flanges & AN lines are the only way to go.

Time is really tight for me now (damned day job!), but I plan to pull the pipe off ASAP, and get a better look at it from the inside. If it looks like the inside is free of corrosion, and if the elbow is solidly attached to the flange and shows no signs that it could get worse, I'll take the gamble and soldier on to DGRR with it as is, and ship it off to Garfinkle's when I return for a repair or getting custom AN flanges made up. What I might try doing while it's out is see if I can squeeze some RTV in the space between that shield piece and the exterior of the elbow while it's off - that might be sufficient to reduce/stop the leak temporarily if it's not under much pressure.

djmtsu · 04-19-2011, 11:39 AM

Talk to Himni Racing.

http://www.himni-racing.com/index.php

Pete_89T2 · 04-22-2011, 08:03 AM

Update - two nights ago I pulled to pipe off to inspect the thing internally and assess the risk that it might become a gusher leak on the DGRR trip. Good news is it looks like the brazed joint between the pipe & flange appears solid. Put the flange in a vise and tried deflecting the elbow relative to the flange by twisting it and pushing/pulling, and couldn't get it to budge. The inside of the elbow and joint with the flange looks to be corrosion free & clean. Should have taken some pictures. Anyway, I put it back on the car with a new gasket & RTV, and after making sure everything was cleaned up, I let the car idle on the jack stands for about 30 minutes - no oil leaking after all that time. So yesterday I decided to use the car to commute to work (50 mile round trip, plus a few miles out for lunch), and took another look underneath when I got home. There was a hint of an oil film starting to form on that same spot on the elbow, but it hasn't quite become a drop yet. So with frequent dipstick checks and a few extra quarts of oil onboard, I think the DGRR trip will be a low risk proposition.

RETed · 04-23-2011, 05:07 AM

I agree - you should be safe.
The key is that that part of the system is not pressurized.
So, since we're dealing with relatively low (oil) pressure, you should not spring a significant leak that could compromise your engine life.
Enjoy the trip!

-Ted

04-17-2011, 07:08 PM	#1
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD iTrader: (1) Posts: 874 Rep Power: 15	Turbo oil return pipe leak Figures, less than 2 weeks to DGRR '11, and I find this. It's on my S5 T2, brand new BNR stage 1 turbo rebuild, but with the old stock return pipe. Leak is a tiny one, and apparently due to a corrosion induced pinhole leak where the elbow joins up with the flange, on the turbo side. It's definitly coming from there, and not the gasket or anywhere else. Questions: 1. Anyone have a good oil return pipe for an S5 T2 they want to sell? 2. What kind of oil pressure & oil flow volume do these oil return lines typically see? This pinhole leak is really tiny; the car has to be running for a long time before a bead of oil even starts to ooze out. In the event I can't fix this before the DGRR trip, I was wondering how much of a risk it would be assuming I carry a plentiful supply of Castrol and check the oil often. DGRR trip will be close to 2K miles round trip, including all the driving in/around the area.

04-19-2011, 11:39 AM	#10
djmtsu My minds tellin' me no... Join Date: Feb 2008 Location: Murfreesboro, TN iTrader: (10) Posts: 4,043 Rep Power: 21	Talk to Himni Racing. http://www.himni-racing.com/index.php __________________ 1976 Mazda Cosmo RX-5 1976 Mazda Cosmo RX-5 2003 Toyota Tundra TRD 2015 Toyota 4Runner SR5

04-18-2011, 03:54 AM	#4
Garfinkles Motor Works RCC Contributor Join Date: Mar 2008 iTrader: (11) Posts: 535 Rep Power: 17	Can I braze the area around the flange ? Cheep and easy .I do make flanges for oil lines for 3rd gens but time is not on your side .

04-18-2011, 07:37 AM	#5
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD iTrader: (1) Posts: 874 Rep Power: 15	Yeah, it's definitely the oil return pipe (bottom of turbo). Gaskets were RTV'ed on assembly. I know it's not leaking from the gasket by inspecting it, here's why. The stock return pipe on the S5 turbo (turbo side) is basically a flange with an elbow pipe brazed/welded into it; there is also a sheet metal piece that sort of shields the OUTSIDE surface of the elbow, which is attached to the flange, probably brazed/welded as well to the outside of the flange (as it doesn't come off). My oil leak can only be seen right at the low spot at the bottom of the elbow, in the space BETWEEN the elbow and the sheet metal shield piece if that makes sense. No oil is seen anywhere on the outside of the flange, or the outside surface of the metal shield piece, the turbo or from places above (i.e., oil inlet line). So the leak has to be coming from the brazed joint where the elbow pipe enters the flange. I like Garfinkle's idea of fixing it, but not sure if that's do-able with that shield piece in the way? Might just be easier (and maybe cheaper than a new Mazda part) to fab up some flanges and use properly sized AN line/fittings. Since it sounds like this leak isn't likely to become a gusher, do you guys agree I can press on to DGRR and deal with it when I return if necessary?

04-18-2011, 08:03 PM	#6
Garfinkles Motor Works RCC Contributor Join Date: Mar 2008 iTrader: (11) Posts: 535 Rep Power: 17	Pull off the pipe and overnight it to me. or get a new one if the price is good .

04-19-2011, 07:42 AM	#8
Garfinkles Motor Works RCC Contributor Join Date: Mar 2008 iTrader: (11) Posts: 535 Rep Power: 17	What if the damage is on the inside and compleatly around the pipe and only a small leak has developed at this time but the rupture is waiting to gush oil .I do not risk failure of a part that I can fix .

04-19-2011, 09:01 AM	#9
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD iTrader: (1) Posts: 874 Rep Power: 15	Well I just checked with Ray Crowe at Malloy Mazda on the price of a new pipe - turns out this part is out of production and there isn't a single one left anywhere in Mazda's inventory. So price is a moot point and a repair of the existing part or fabbing up custom flanges & AN lines are the only way to go. Time is really tight for me now (damned day job!), but I plan to pull the pipe off ASAP, and get a better look at it from the inside. If it looks like the inside is free of corrosion, and if the elbow is solidly attached to the flange and shows no signs that it could get worse, I'll take the gamble and soldier on to DGRR with it as is, and ship it off to Garfinkle's when I return for a repair or getting custom AN flanges made up. What I might try doing while it's out is see if I can squeeze some RTV in the space between that shield piece and the exterior of the elbow while it's off - that might be sufficient to reduce/stop the leak temporarily if it's not under much pressure.

04-22-2011, 08:03 AM	#11
Pete_89T2 Lifetime Rotorhead Join Date: Apr 2010 Location: Elkton, MD iTrader: (1) Posts: 874 Rep Power: 15	Update - two nights ago I pulled to pipe off to inspect the thing internally and assess the risk that it might become a gusher leak on the DGRR trip. Good news is it looks like the brazed joint between the pipe & flange appears solid. Put the flange in a vise and tried deflecting the elbow relative to the flange by twisting it and pushing/pulling, and couldn't get it to budge. The inside of the elbow and joint with the flange looks to be corrosion free & clean. Should have taken some pictures. Anyway, I put it back on the car with a new gasket & RTV, and after making sure everything was cleaned up, I let the car idle on the jack stands for about 30 minutes - no oil leaking after all that time. So yesterday I decided to use the car to commute to work (50 mile round trip, plus a few miles out for lunch), and took another look underneath when I got home. There was a hint of an oil film starting to form on that same spot on the elbow, but it hasn't quite become a drop yet. So with frequent dipstick checks and a few extra quarts of oil onboard, I think the DGRR trip will be a low risk proposition.