projectresto83

This is not mustang specific but a wastegate is a wastegate. Its on a buddies SRT4. He was out running around one night and had it at full boost (20+ psi) and when he let if he heard something or something like that IDK I wasn't with him and he isn't the best at explaining things. He blew off the flexpipe that is welded into the exhaust right after it comes off the wastegate and he says it has no performance at all. But anyway exhaust is just free flowing thru the dump tube (well what is left of it) at idle and when you hit the throttle. Wouldn't that mean his wastegate is broken or at least stuck open? Could a broken/leaking vac line cause this too somehow?

FoxGT

Need a better explanation if possible. Does he still have the stock turbo? Most srt4's come with the turbo built into the exhaust & use an integral wastegate which means there is no flex tube in the system before the wastegate. After the wastegate, it wouldn't matter if something broke in terms of the turbo spooling. If you're talking about the flex joint after the turbo/before the catalytic converter, that wouldn't cause it to stop producing boost, that would however cause the 2nd o2 sensor to get an incorrect reading.

A lot of cars won't produce boost when just revving the engine. If it won't produce any when he's getting on it going down the road, it could be caused by quite a few things (sensors causes aside); a hose on the intake side loose, the clip that holds the wastegate rod to the wastegate door may not be on causing the rod to disconnect from it, the wastegate failing, or the turbo failing.

A broken vacuum/pressure line would cause the turbo to overboost.

More information would help narrow it down.

FoxGT

edit: double post

projectresto83

Well like I said in my description the flextube that is comming off the wastegate was blown off. It is a turbonetics wastegate and some larger turbo. So the wastegate sits in front of the #1 and #2 cylinder so all the exahust gas flows straight out of that instead of thru the turbo. Wastegates only operate at the set max boost anyway so it shouldn't be letting the exhaust flow thru. Thanks for the reply but we have already talked and he is ordering a new/bigger one anyway.

Blackbetty04

i hope i can shine some light on the explanation, Ok it is a 50trim turbo mounted on the cast iron exhaust mani, The waste gate mounts between the number 1 and 2 exhaust port which pust the turbo closer to the 3 and 4.
I has a external waste im sure the size dosent matter here. I have both )2 sensors hooked up but only 1 of them is where it is suppose to be as the down pipe only allows one and it had been that way since its big turbo. I can only think that the wastegate is suck open and with the flex tube that dumps into the exhaust down stream is allowing to much of the exhaust out of the wast gate and not allowing it to go through the turbo to produce boost, and I am saying that as in a perfect world that it has no exhaust leaks. I am the owner of the car but thats what i came up with. Anyones advice?

FoxGT

so it's broken AFTER the wastegate? Where is the flex tube?

In any case, can you get take the wastegate off easily or is it a hassle?

Blackbetty04

yes, the flex tube comes off of the wastegate and connects to the exhaust, the wastegate is a pit of a hassle but i am going to change it out to a tial 44mm wastegate with a different mani and dump tube

FoxGT

can you feel any exhaust coming out of it at idle?

projectresto83

As it says in the my first post, yes.

FoxGT

Sounds like a wastegate issue then. You can test it with a small manual pressure pump.