boost leak, boost solenoid, Something else?

**yamaha_rider619** · 12-22-2009 10:32 PM

I did a pressure check and could not find and leaks in my system. I have a 2003 wrx with an aftermarket turbo inlet hose and a turbosmart bov, which i will be removing in the morning. I only run .05 Mpa, or 7.25 psi. Could this be a solenoid, or something else?

**Donkey** · 12-23-2009 05:05 AM

If the car has always run this boost then you are probably missing the pill in the vacuum line on the compressor. If the car just started doing this recently and you have a CEL then you need to pull the code. The car/ECU is unhappy and has the ability to run wastegate pressure to save the motor. If no CEL then it could be the solenoid,boost leak or preturbo exhaust leak.

**yamaha_rider619** · 12-23-2009 09:20 AM

when i first bought the car it had no pill, then i took it to super rupair and they put one in for me. Before the pill i was hitting 14 psi, now i only get 7.25 psi. I also have no CEL's. And i did a boost leak test last night and coudnt find any, how do i know if its a boost solenoid or a preturbo exhaust leak?

**Donkey** · 12-23-2009 12:31 PM

Originally Posted by yamaha_rider619

when i first bought the car it had no pill, then i took it to super rupair and they put one in for me. Before the pill i was hitting 14 psi, now i only get 7.25 psi.

So are you saying once you put the pill in the boost went down? Did you buy the car modded? List every single performance mod. If you bought the car modded and don't know what exactly has been done to it then it's going to be hard to help you.

**yamaha_rider619** · 12-23-2009 01:18 PM

Originally Posted by Donkey

So are you saying once you put the pill in the boost went down? Did you buy the car modded? List every single performance mod. If you bought the car modded and don't know what exactly has been done to it then it's going to be hard to help you.

When i bought the car it had a hks mega flow intake and a catback exhaust, made by hks i think, but am not sure, and a lamco boost gauge. A carbon fiber hood to, but that doesnt mean anything.

I just put the stock bov back in and the pressure for the boost feels better, but my guage still only says 7.25 psi. Could the restrictor pill be the wrong type or size or anything like that?

**wilson** · 04-24-2011 07:10 PM

and i have just 5psi and idont have any vacuum leak so is posible that causinme the problem because when my turbo boost start workin the car start to feel like loose the power and dont go any faster can some one helpme aneed to fix da and i dont have any other clue of whats going on

**Donkey** · 04-24-2011 07:28 PM

Originally Posted by wilson

and i have just 5psi and idont have any vacuum leak so is posible that causinme the problem because when my turbo boost start workin the car start to feel like loose the power and dont go any faster can some one helpme aneed to fix da and i dont have any other clue of whats going on

. Engrish.......

**yamaha_rider619** · 04-24-2011 08:20 PM

Agree with donkey! But thanks for searching. Yes if you have a pre-turbo leak you won't get full boost. Get that fixed, pre-turbo leaks are bad

**Salica** · 05-02-2011 07:56 PM

Someone else with the same problem has posted a thread.

It seems to me that the wastegate solenoid controller(stock boost controller) is at fault. My car has been doing the same thing 7 psi at max boost. I have changed all my vacuum hoses and i checked for the pill which was in the car. I even tried spraying some lubricant in the wastegate just in case the spring was stuck. It seems to me that my wastegate controller is at fault but i have no clue on how to test it( can we just use a DMM and test for continuity?). My presumption is that this part is giving out. If you find something out let me know. :-)

-Sal

**Donkey** · 05-03-2011 11:48 AM

It's a 12volt unit and can be tested by either placing the car in diagnostic mode or attaching test leads to the solenoid and energizing it straight from the battery. You should here it clicking/actuating.

**Salica** · 05-03-2011 05:53 PM

Could i just disconnect the vacuum hose that flows to the wastegate and turn the car on? if there is no air passing by does that mean the wastegate solenoid valve is closed and therefore not working? if air is passing by at idle then maybe i could rev the car and see if the controller closes early(knock sensor)?

Does this sound like a viable way to test the wastegate solenoid valve(controller)?

-sal

**Donkey** · 05-04-2011 08:24 AM

The air is coming from the wastegate line so disconnecting it would not help you diagnosis the problem. The solenoid is normally closed. It is set up to bleed off air by the ECU using a varying duty cycle that is done by rpm vs throttle position. What does the knock sensor have to do with this? Not sure what was wrong with the ways I suggested......

**Salica** · 05-07-2011 08:11 PM

You are right there is nothing wrong with what you had suggested. I had an idea that would keep me from doing any electrical work. I was also mentioning the knock sensor because i read on different site that if the engine is knocking the solenoid valve will bleed off the air earlier to protect the engine.

Either way i just bypassed the solenoid valve to see if the car would boost past .05 Mpa and it did so i have now narrowed down the problem.

**Sinister** · 05-07-2011 09:22 PM

Just kind of an update on Yamaha's situation... just in case someone else searches and finds this and has the same problem. (7psi boost, and no check engine light)

If you purchased the car and are unsure of the modification history of the car... before you pay someone to fix it, pull the tune. If a person had previously had a Manual Boost Controller installed, or an aftermarket electronic boost controller (not a boost control solenoid) then the Wastegate Duty Cycle will have been set to 0. This was the case in Yamaha's situation. A simple tune fixed his problem.