Boost Problems

[Boosted516]

I just installed my greddy profec type-s boost controller and I was trying to mess around with my boost. This is when i realized my car wont hold anything more than 5psi, even without the boost controller my car would hit 6, then go back down to 5. Sometimes with the boost controller it will spike at about 9 or 10 then go back down to 5 or 6. I was thinking boost leak(s) but then i read something on a dsm forum about turbos with a small amount of shaft play(which i have) having air escape through the oil lines and then escaping through the breathers in the valve covers. I doubt this is whats wrong with my car, but it got me thinking. What are some reasons this could be happening?

 

[lewis15498]

I just installed my greddy profec type-s boost controller and I was trying to mess around with my boost. This is when i realized my car wont hold anything more than 5psi, even without the boost controller my car would hit 6, then go back down to 5. Sometimes with the boost controller it will spike at about 9 or 10 then go back down to 5 or 6. I was thinking boost leak(s) but then i read something on a dsm forum about turbos with a small amount of shaft play(which i have) having air escape through the oil lines and then escaping through the breathers in the valve covers. I doubt this is whats wrong with my car, but it got me thinking. What are some reasons this could be happening?

This can happen, if it does it can pressurize your crankcase and you can end up pumping your oil out through the breathers as well. happened to me, significantly enough that oil ran onto the manifold and caught on fire.
Something to keep in mind.

I would start with a boost leak test.

 

[paradox616]

I just installed my greddy profec type-s boost controller and I was trying to mess around with my boost. This is when i realized my car wont hold anything more than 5psi, even without the boost controller my car would hit 6, then go back down to 5. Sometimes with the boost controller it will spike at about 9 or 10 then go back down to 5 or 6. I was thinking boost leak(s) but then i read something on a dsm forum about turbos with a small amount of shaft play(which i have) having air escape through the oil lines and then escaping through the breathers in the valve covers. I doubt this is whats wrong with my car, but it got me thinking. What are some reasons this could be happening?

sounds like blowby, could be from piston rings or as mentioned above, you'll find oil in your accordion pipe i bet and Weak wastegate spring, happens as they get older

my ct26 does the same thing! try shimming your wastegate, the aim is to put more pressure on the flapper. mine would boost to 8-9psi then drop to 5psi. now it holds 8 stable with a few shims and the controller or 6-7psi with just the actuator, i also run a gizmo electronic closed loop controller i've got a new actuator i need to fit

 

[Boosted516]

sounds like blowby, could be from piston rings or as mentioned above, you'll find oil in your accordion pipe i bet and Weak wastegate spring, happens as they get older

my ct26 does the same thing! try shimming your wastegate, the aim is to put more pressure on the flapper. mine would boost to 8-9psi then drop to 5psi. now it holds 8 stable with a few shims and the controller or 6-7psi with just the actuator, i also run a gizmo electronic closed loop controller i've got a new actuator i need to fit

how can i be certain this is the problem, a compression test?