New Evo III 16g, slow to build boost

[GSTDoIt]

Hi there. I just put in an Evo III 16g over the weekend. When I originally took it out for a test drive, I found that it would not boost. So I took the next day checking for boost leaks. I found a few, so I fixed and re-tested. Now it is fine, but the problem that I am having is that it will not build full boost untill around 4500 RPMs. The MBC is currently set for about 15psi. From what I have read on these forums, it seems to be boost creep. But I want to get any opinions that you guys may have before I end up taking it in. I am going to try turning the boost controller up to allow for more boost and see if that does anything as that is what was suggested in another thread. The 16g is brand new and fully ported along with the 34mm flapper. The O2 housing is also fully ported. My mods are in my profile. Any suggestions would be greatly appreciated. Thanks.

 

[wimploki]

Hi there. I just put in an Evo III 16g over the weekend. When I originally took it out for a test drive, I found that it would not boost. So I took the next day checking for boost leaks. I found a few, so I fixed and re-tested. Now it is fine, but the problem that I am having is that it will not build full boost untill around 4500 RPMs. The MBC is currently set for about 15psi. From what I have read on these forums, it seems to be boost creep. But I want to get any opinions that you guys may have before I end up taking it in. I am going to try turning the boost controller up to allow for more boost and see if that does anything as that is what was suggested in another thread. The 16g is brand new and fully ported along with the 34mm flapper. The O2 housing is also fully ported. My mods are in my profile. Any suggestions would be greatly appreciated. Thanks.

Did you perform a proper boost leak test? On a stock motor with a stock turbo, make sure the intake system can hold 20psi for 30 seconds before bleeding down.

Did you prime your turbo before starting?

Did you check your turbo for shaft play? Minimal side to side is okay. In and out play is considered a bad turbo.

Have you done your tune up lately? Check the condition of your air filter, spark plugs, fluids, and hoses as well. Is your spark plug properly gapped?

Check for exhaust leaks as well.

Do a compression test. This will tell you the condition of your engine.

Good luck

 

[robs90tsi]

I'd also have to say that sounds like a boost leak, especially if youre not boosting until 4500 RPM's, try and redo a boost leak test, see if there's anything you missed. Also, the E16G's are notorious for boost creep, you just have to upgrade/port your wastegate, and turbo, if you bought the turbo ported, they port for flow, not to help with boost creep, try getting your wastegate ported as well.

 

[SiNiST3R]

This may sound dumb but make sure the turbo is on. ie the four top bolts and also the ones to hold on the 02 I've had a turbo hang there before.

 

[kenamond]

You say you set your BC to get 15psi and you're getting this boost, but it is slow getting there. This doesn't sound like creep. Creep is when you exceed the specified boost due to inadequate flow out of the wastegate.

 

[CanadianTSi]

Sounds like an exhaust leak pre turbo to me...

Check for any black marks around where the manifold connects to the head and turbo and triple check all the bolts.

 

[GSTDoIt]

Did you perform a proper boost leak test? On a stock motor with a stock turbo, make sure the intake system can hold 20psi for 30 seconds before bleeding down.

Did you prime your turbo before starting?

Did you check your turbo for shaft play? Minimal side to side is okay. In and out play is considered a bad turbo.

Have you done your tune up lately? Check the condition of your air filter, spark plugs, fluids, and hoses as well. Is your spark plug properly gapped?

Check for exhaust leaks as well.

Do a compression test. This will tell you the condition of your engine.

Good luck

I will be getting a proper boost leak tester very soon, and when I do I will do a proper boost leak test.
The turbo had 0 shaft play when I got it. No in/out or side/side.
The air filter is a K & N and I cleaned it about 3 months ago. Spark plugs were changed about 4-5 months ago with the specified NGKs and gapped to whatever was specified. Tranny fluid was changed 3 months ago, radiator fluid 2 days ago, and oil changed about 800 miles ago.
I will go back over all of the exhaust bolts/nuts tonight and re-check them to make sure they are torqued correctly.
I do not currently have a compression tester, but I will get one and check the compression.

Thanks for the help everyone! I'll keep you updated on the progress as I have time to check the problems.

 

[GSTDoIt]

Ok, so just as an FYI for anyone else who may have this same sort of problem, I was able to figure out what was wrong and fix it. It turns out that the waste gate actuator arm was slightly pushing on the flapper and therefore keeping it cracked open and letting exhaust gas past the turbo at all times. Basically, the arm was too long, with it mounted the way it was stock. So what I did was shim the actuator further back with washers as was suggested in another thread that I read about on here, which pulled the flapper closed. The turbo now boosts perfectly and very quickly.