Wastegate sealed?

[TurboTJ]

I am having uncontrolled boost issues. With boost connected straight to the wastegate, I hit 9psi. when I use a boost controller, I hit 20 before I let off. I was checking for leaks in the vacuum lines and realized that I can blow air through the line going to the wastegate and hear it come out. Should this be happening? I thought that the wastegate would be sealed. The line is fine. This is on a 1 month old evo 3 16G with an internal wastegate. Both boost controllers tested where set to 0 PSI or there minimum settings.

thanks for the help

 

[Mr Peepers]

Is your wastegate actuator itself leaking or just the MBC?
On a ball and spring type MBC a little air should leak on the side that leads to the wastegate.

What brand MBC do you have? Are you sure you don't have it hooked up backwards? Are you sure it's being turned the correct direction?

 

[TurboTJ]

I was blowing straight into the line going to the wastegate (MBC disconnected) so the air is leaking somewhere around the actuator. Is this normal?

I was using a DNA MBC and an AEM electronic BC.

 

[kenamond]

I was blowing straight into the line going to the wastegate (MBC disconnected) so the air is leaking somewhere around the actuator. Is this normal?

I was using a DNA MBC and an AEM electronic BC.

The WGA should be air-tight. If you got the turbo from some vendor, contact them and see about getting a replacement.

What's weird is that you were able to hold 9psi without the MBC in the loop. If the WGA was leaking bad enough, you'd have the same situation with the MBC set to 0psi (as you say) as you had with a vaccuum line straight from the boost source to the WGA. The fact that they behave differently makes me think you have a boost controller issue. But I don't think that the e3b16g WGA should leak.

 

[oldman]

1. If you can hear the leak, find it by spraying soapy water and apply compressed air directly to the actuator, while you're at it, perform a thorough boost leaks test. If you have a 3" intake pipe, make sure it's not sitting on top of the actuator fitting resulting in a pinched hose, this is a very common problem.

2. The wastegate leak aside, the issue here clearly points to the MBC or how it's hooked up. Let's forget about the AEM for now and focus on the DNA mbc, assuming you only had one of them hooked up at a time. Is the DNA MBC a ball/spring or bleeder type mbc? How exactly is it hooked up? Give us all the details including the direction of adjustment, clockwise or counter clockwise.

Bottom line, your wastegate is functioning properly, leaking or not, because it ran 9psi without the MBC. Problem is the mbc isn't sending any signals to the wastegate resulting in out of control boost, much like running with the actuator fitting open to the atmosphere.

 

[TurboTJ]

I just boost leak tested it about 2 weeks ago with no problems. But it is the actuator leaking. I would guess that it behaves differently with a MBC because that limits air flow. The MBC doesnt allow enough to open it. With it connected straight to boost, it has all the flow that it needs.

Is there any chance of me being able to fix it?

thanks for the help!

 

[oldman]

I just boost leak tested it about 2 weeks ago with no problems. But it is the actuator leaking. I would guess that it behaves differently with a MBC because that limits air flow. The MBC doesnt allow enough to open it. With it connected straight to boost, it has all the flow that it needs.

Is there any chance of me being able to fix it?

It's a possibility but it is just a guess at this point which needs to be verified, you can't consider fixing something until you verified that it's broken. Where exactly is it leaking? How about answering my previous questions? You may have a leaky actuator but I still think the problem is the MBC or the hook up.

 

[TurboTJ]

1. If you can hear the leak, find it by spraying soapy water and apply compressed air directly to the actuator, while you're at it, perform a thorough boost leaks test. If you have a 3" intake pipe, make sure it's not sitting on top of the actuator fitting resulting in a pinched hose, this is a very common problem.

2. The wastegate leak aside, the issue here clearly points to the MBC or how it's hooked up. Let's forget about the AEM for now and focus on the DNA mbc, assuming you only had one of them hooked up at a time. Is the DNA MBC a ball/spring or bleeder type mbc? How exactly is it hooked up? Give us all the details including the direction of adjustment, clockwise or counter clockwise.

Bottom line, your wastegate is functioning properly, leaking or not, because it ran 9psi without the MBC. Problem is the mbc isn't sending any signals to the wastegate resulting in out of control boost, much like running with the actuator fitting open to the atmosphere.

Bottom line: I have 2 boost controllers not working which is very unlikely. I read the instructions 10 times for both and tested everything. It is the wastegate solenoid leaking for sure. I even tested the line running to it. Does my previous explanation make since or does that not work out logically?

As for the DNA, counterclockwise = less boost
Here is the site. I printed the directions and checked the setup 10 times
http://www.dnamotorsport.com/Products/Boost_Controller/Boost_Controller.htm

thanks for all the help

 

[TurboTJ]

It's a possibility but it is just a guess at this point which needs to be verified, you can't consider fixing something until you verified that it's broken. Where exactly is it leaking? How about answering my previous questions? You may have a leaky actuator but I still think the problem is the MBC or the hook up.

Here is my process:
I pulled off both lines to and from the boost controller. I tested them both to make sure that they hold boost. I then connected one line back to the actuator. I blew through it. There was NO restriction, it was like the other end wasn't even connected.

thats what led me to my hypothesis.

 

[oldman]

As for the DNA, counterclockwise = less boost
Here is the site. I printed the directions and checked the setup 10 times
http://www.dnamotorsport.com/Products/Boost_Controller/Boost_Controller.htm

This is what bothers me,

1. Loosen the lock nut
2. Turn adjusting screw ¼ of a turn anti-clockwise to begin with
3. Tighten lock nut
4. Check boost level
5. If you wish to increase boost more, with the lock nut tight use small screwdriver to open valve more while holding lock nut
6. Once you reach desired boost level tighten lock nut, you may use a thread locking liquid for added security

To me, "use small screwdriver to open valve more" means counter clockwise, this contradicts your statement. If in fact I interpreted the direction correctly, this is a bleeder type mbc, loosening (CCW) the screw = more air being bleed off = less pressure to the wastegate = higher boost level.

 

[oldman]

I pulled off both lines to and from the boost controller. I tested them both to make sure that they hold boost. I then connected one line back to the actuator. I blew through it. There was NO restriction, it was like the other end wasn't even connected.

thats what led me to my hypothesis.

Something is not right, if it can't even hold less than 1 psi, how can it possibly give you 9psi of boost, you will most certainly get all out boost all the time. I'm still not convinced.

 

[kenamond]

Here is my process:
I pulled off both lines to and from the boost controller. I tested them both to make sure that they hold boost. I then connected one line back to the actuator. I blew through it. There was NO restriction, it was like the other end wasn't even connected.

thats what led me to my hypothesis.

If the WGA is leaking that badly, it may be that adding an MBC in-line - even set at 0psi - will have a boost control effect in that it restricts the air flow enough to let the WGA leak down faster than the MBC is letting air through.

But I'm still suprised that you held 9psi boost with the boost source straight to the WGA if the WGA is leaking that badly. Could be the case since you do have a fair flow of air through a simple vaccuum line.

Anyway, if it's leaking that badly, you definitely need to get a new WGA or see if you can somehow fix the leak. Like oldman said, verify that it's leaking from the WGA first. If it's as bad as you say, it may not make soapy bubbles, but you should be able to feel the leak or have someone get their ear right up next to it.

Also, make sure you don't have a hole in the vaccuum line to the WGA that might just sound like it's leaking at the WGA. Did you use a different line when you ran 9psi straight from the boost source to the WGA?

 

[TurboTJ]

Thanks for all the help!

I was gonna test everything tomorrow but you guys raise good questions. I am going to take a closer look right now.

as for the boost controller, It says open the valve = more boost; to me this means CCW but they need to be much more specific. I will post what I find.

 

[TurboTJ]

With the line back on the solenoid, I blew into it and it leaked at the nipple badly. I then put my clamp back on and it continued to leak. Even with the clamp tightened fully (as it was before), it leaks at under 1 PSI. Guess its time for smaller vacuum lines? This may still not be the problem because the turbo worked great for about a month. I will check everything tomorrow.


Thanks for all your help!

 

[oldman]

Just making sure the BCS has been removed. When you said solenoid, you mean the wastegate actuator, not the boost control solenoid right?

BTW was the mbc turned all the way out during testing because you thought it would decrease boost?

 

[TurboTJ]

The stock boost control solenoid was removed.

the MBC was turned all the way in during the test.

It appears that the problem is fixed! I put on the thinner vacuum line that came with my greddy rs. It fits more snug on the wastegate. It didnt leak. I put it all back together and I was actually able to hold down boost! The vacuum line that was on it has a much thicker wall. I think this didn't let it fit snug around the nipples contours.

Looks like problem solved! Thanks for all the help!