Help Plz

[90DSMTurbo]

Hey

i installed my new turbo a few days ago, and well i press the gas and i get boost fine till 5 psi then it hisses like a beast

i checked all my connections and they are solid is it possiable i have a bad wastegate?

thanks

 

[Bohrn]

Wastegate shouldn't hiss if it is open. It goes directly out the exaust pipe. Of course, I have never taken one apart, but to my understanding that is how it works. The wastegate doesn't dump boost, but stops the impeller from getting exaust to turn it.

Now you may have a bad Blow off Valve. If that leaks you might hear a hiss. Also there are alot of areas that could leak under pressure. You will have to pressure test your system. Block off the turbo inlet and pump up the system with a bike pump attached to the turbo outlet outlet nipple. It is on the top of that elbow that comes out of the turbo. You will have to cut off the tire fitting on the pump. Make sure that the plug is in the turbo intake VERY well, as your system should hold 20 psi. Do this at a quiet time, and you will hear the leak if there is one. Remember that rubber pipes and connectors will stretch under pressure, so what looks fine while the engine is at idle, may be a whole different story under boost.

best of luck

 

[90Turbo]

I beleive thats normal for a turbo to hiss when boost increases. Mine does, but then again I have no exhaust so it whines, I love it. Here is a description of how mine goes, I step on the gas and it starts sssssssssshhhhhhhhhhhhh, I shift then pppppssssshhhhhhhhhhh, ssssssssssshhhhhhhhhhhh ppppppppppssssssssssssssshhhhhhhhhh

Everything sounds normal, are you holding boost after the wastegate opens. If boost is falling off that means you have a leak, but if it stays steady you good to go and you have nothing to worry about.