overboost

[khvolk1s]

I have an 03.5 MSP and have noticed the following on my boost gauge
1st-4psi
2nd-10psi
3rd-13psi
4th-15psi
I know the factory settings are 7psi so idk whats going on here I'm the third owner of this car so I have considered some knuckle head monkey business, but for the life of me I can't find a boost controller anywhere on the car. Under the hood it looks stock except for an injen intake. The guys at my local mazda dealer are stumped. I don't think the internals have been upgraded, and I really don't want to detonate the engine, so I need some answers/suggestions. Is this normal? is it a bad gauge? could this be an ecu flash?

 

[hornsfan10609]

Could be a bad wastegate actuator, pull off the vacuum hose leading to it and blow air into it. If any air passes it is shot and needs to be replaced, it if doesn't pass any air as hard as you can blow it is probably fine. A leaking vacuum hose could also cause this, but would also have worse driveability when not under boost.

 

[bluemp301]

It almost looks like a race setup with the boost set per gear. But if the car is pretty much stock I'm puzzled. Where did you get the car from?

 

[Alamo1]

The guy could have cut the actuator rod and made it adjustable therefore putting more preload on the spring inside. Really the only way to check that is to have the turbo off though.

 

[hornsfan10609]

The stock WGA is adjustable but it may have failed altogether.

 

[khvolk1s]

first of all thank you to you all for replying... now: The guys at Benning Mazda thought the waste gate had been "bent open" but they said it looks fine, but Ill try the hose thing anyway. I got the car from Lou Fusz Chevrolet in St. Peters Mo (suburb of STL), I have already called and tried to get info on the last owner, but the person who could help was busy. admittedly, My tuner knowledge is at a minimum but I am learning as I go, so I have no idea about the actuator rod. The biggest problem I am having is that this car is so rare that hardly anyone knows anything about it... the dealerships top gear head had only ever seen one other before so it just hard to find anyone who knows the car intimately.

 

[khvolk1s]

replaced the wategate, and now she runs like a champ. Boosts all the way to 9psi under full throttle which I understand is a safe level. Thanks to everyone for helping.

 

[hornsfan10609]

It's not extremely safe but as long as you don't go over 9 without a tune and upgraded intercooler you probably won't snap the connecting rods.