Just a quick question about boost leaks.

[boosted92laser]

Now that I have my oil pressure problem under control, I did a boost leak test. I filled it with 20psi and heard a hissing and kind of a bubbling sound. I figured out where my only two leaks are. One is the turbo oil return line, it has a small crack in the flex section, which I am going to replace before I drive the car anymore. The other spot it is leaking from is the dipstick tube. If i pull the dipstick out, all (but about 5psi) of the pressure will come shooting out. I did some searching, but didn't find the information I was looking for. Is this normal? If not, what can I do to fix it?
Thanks

 

[romeen]

It could be your PCV valve leaking allowing pressure into the crankcase. You may want to start by replacing it with an oem valve. If you want to test it, unscrew it from the valve cover but leave it hooked up to the IM and repeat the leak test. Check for air leaking past the valve. Do you still have the valve cover breather connected to the intake pipe like the stock configuration?

Did you notice alot of air escaping through the crack in the oil return line? It is normal to have a small amount of air leak past the turbo seals when the motor is not running but if they are on their way out then that could be another source of excessive air getting into the crankcase.

 

[boosted92laser]

It could be your PCV valve leaking allowing pressure into the crankcase. You may want to start by replacing it with an oem valve. If you want to test it, unscrew it from the valve cover but leave it hooked up to the IM and repeat the leak test. Check for air leaking past the valve. Do you still have the valve cover breather connected to the intake pipe like the stock configuration?

Did you notice alot of air escaping through the crack in the oil return line? It is normal to have a small amount of air leak past the turbo seals when the motor is not running but if they are on their way out then that could be another source of excessive air getting into the crankcase.

I do have my vc breather connected to the intake pipe just like stock. But to do the test, I took the hose off the vc and plugged the nipple on the vc. I will buy a new pcv valve tomorrow at work and try it again.
Thanks

 

[boosted92laser]

I have a quick question about the oil return line. I do know that mine has a leak. I have a buddy that can make a new line with braided line. He is able to crimp new ends on to a reinforced braided line and he said it should work.
Would anybody know a reason why it wouldn't work?
He can do this for like $15, instead of searching to find one and paying $30+ for it.
Any input would be great.
Thanks

 

[romeen]

As long as the inner diameter of the line is the same as the stock line it shouldn't be a problem. If it is smaller I believe it would result in excessive oil pressure through the turbo which may result in failure of the seals.

If you are short on cash you can cut out the damaged portion of the stock line. Then use some fuel hose to replace that portion which you cut out. The fuel hose will slide over the cut ends of the stock pipe and be secured with clamps. This will allow you to use the original flanges for the ends. I'm not sure if this is what you are referring to or not. But you mentioned using "new ends" so I'm a little confused.

 

[boosted92laser]

As long as the inner diameter of the line is the same as the stock line it shouldn't be a problem. If it is smaller I believe it would result in excessive oil pressure through the turbo which may result in failure of the seals.

If you are short on cash you can cut out the damaged portion of the stock line. Then use some fuel hose to replace that portion which you cut out. The fuel hose will slide over the cut ends of the stock pipe and be secured with clamps. This will allow you to use the original flanges for the ends. I'm not sure if this is what you are referring to or not. But you mentioned using "new ends" so I'm a little confused.

My guy actually has access to new flanges exactly like the originals, even though they use them on industrial equipment. He said that he has 5/8" braided hose that will fit right on the flanges and then be crimped on.
I don't really want to 'rig' it so it will work, I want it fixed right.

 

[twicks69]

Have you checked your compression?

How new is your head gasket? ARP head studs used?

Also, if you are able to, get your hands on a leakdown tester.

Did you check all vacuum/boost connections including the intercooler, blow off valve, boost controller, IC pipe couplers, etc. to find where the hissing sound was coming from?

Did you check to see if you have coolant bubbling into your overflow tank when you are doing a boost leak test? The bubbling sound is usually a sign of a head gasket failure, or dead piston rings.

 

[boosted92laser]

Have you checked your compression?

How new is your head gasket? ARP head studs used?

Also, if you are able to, get your hands on a leakdown tester.

Did you check all vacuum/boost connections including the intercooler, blow off valve, boost controller, IC pipe couplers, etc. to find where the hissing sound was coming from?

Did you check to see if you have coolant bubbling into your overflow tank when you are doing a boost leak test? The bubbling sound is usually a sign of a head gasket failure, or dead piston rings.

I did a compression test 500 miles ago.

Head gasket is 800 miles old. I used Mitsu head bolts (I couldn't wait for studs)

All connections were checked when boost leak test was done. No leaks anywhere but a vacum line (which I fixed), oil return line, and dipstick.

The bubbling was not coolant, it was oil in my turbo return line. There was no bubbling at all in the coolant.

 

[twicks69]

Ok, thank you for the response.

Either way, if air is getting to the oil, there is a seal leak with either the turbo or the engine.

I hope that you have fixed all your problems, and that I am able to help in the future.

Good luck,

 

[kenamond]

I did a compression test 500 miles ago.

Head gasket is 800 miles old. I used Mitsu head bolts (I couldn't wait for studs)

All connections were checked when boost leak test was done. No leaks anywhere but a vacum line (which I fixed), oil return line, and dipstick.

The bubbling was not coolant, it was oil in my turbo return line. There was no bubbling at all in the coolant.

It is recommended to pull your oil cap during a boost leak test so that you do not pressurize your crankcase. Next time, don't plug the VC breather or pull the oil cap.

Also, do the test romeen originally suggested for your PCV valve. If the PCV is leaking, you can put your thumb over the "snorkel" pipe and see what else is leaking.

Don't forget to test on a warmed-up motor so that the rings are sealed.

Leaking past the turbo seal is okay as long as you don't have excessive shaft play. If you test at the TB elbow, you can eliminate the turbo seal leak from the test.

This is a guess, but I'd think that the return pipe/line from the turbo doesn't have to be huge, as the oil supply is a very small line.

How are your compression numbers?

 

[boosted92laser]

It is recommended to pull your oil cap during a boost leak test so that you do not pressurize your crankcase. Next time, don't plug the VC breather or pull the oil cap.

Also, do the test romeen originally suggested for your PCV valve. If the PCV is leaking, you can put your thumb over the "snorkel" pipe and see what else is leaking.

Don't forget to test on a warmed-up motor so that the rings are sealed.

Leaking past the turbo seal is okay as long as you don't have excessive shaft play. If you test at the TB elbow, you can eliminate the turbo seal leak from the test.

This is a guess, but I'd think that the return pipe/line from the turbo doesn't have to be huge, as the oil supply is a very small line.

How are your compression numbers?

I must have missed the line that said to take the oil cap off. I did it just like vfaq said.

I have a new pcv valve so I will throw that in tomorrow and do it again.

The turbo has no shaft play. How do you test at the throttle body elbow? That will just test for leaks in the engine, right?

I will do another compression test tomorrow and post the numbers.

 

[Dream On]

At the TB elbow you'll be able to isolate leaks better if you have a lot in your intercooler/ IC piping. Check the TB gaskets, IM gasket, BISS o ring, tb shaft seals, injector insulators, and any vacuum lines that you've still got going to the IM or TB.

 

[boosted92laser]

Thanks guys for the help.
One of my managers quite at work, so I will be working like 80 hours for the next couple weeks so I won't even have a chance to look at it anymore. I'm just glad that I have another car to drive in the mean time.