Subaru WRX Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
292 Posts
Discussion Starter · #1 ·
Arrrgh, something is wrong with my WRX! I've noticed over the past few weeks it doesn't pull as hard nor throws me in the seat like it used to. Now that I installed the guage, my fears were confirmed. My guess is that if I see -20+ psi then I probably don't have any boost guage tubing leaks. I tapped the boost from the BOV hose and from the hose connecting to the intake manifold. Same readings on both.

I installed the Autometer Boost guage and here are my readings:

idle: -19psi
in gear, off gas: -22psi
1st: 5psi
2nd: 9psi
3rd: 9psi
4th: 9psi
5th: 8psi

There is no drop in boost either like there should be when I get closer to redline. Everything from 3k rpm - 6.5k rpm feels slugish.

Bad turbo? Bad Wastegate?

The only mods I have on the car are a GFB BOV, silencer removal, and the boost guage.

-- Rich
 

·
Registered
Joined
·
3,501 Posts
Rich, it sounds like you hooked something up wrong. Look at the wastegate actuator hose and make sure everything looks OK with the T connection that goes to the solenoid. You should never be seeing vacuum pressures that high (-19 psi) on your gauge. You might have a boost leak or malfunctioning wastegate.

Good luck. I hope you can figure this out!

-Jim
 

·
Registered
Joined
·
192 Posts
Is your autometer guage like the one on the left?
If it is, then you're seeing 19 inHg at idle, which is normal. 29.92 inHg is 1ATM, or 14.7psi.

Assuming that the scale below zero is in inHg, and your guage is functioning correctly, sounds like you have a boost controller problem. You say you don't have any sort of aftermarket boost controller?

If you run a straight hose from the turbo outlet nipple to the wastegate actuator (so the wastegate actuator is always seeing boost pressure) then the wastegate will open at its spring pressure, which is around 9 lbs.

On a stock wrx, there is a hose from the turbo outlet nipple connecting to a T. From this T, one hose goes to the boost control solenoid and one hose goes to the wastegate actuator. Normally the boost control solenoid's ports are open, so there is no pressure in this line - therefore the wastegate actuator sees no pressure and the wastegate stays shut (allowing further turbo spoolup). When max boost is reached, the ecu sends a signal to the boost control solenoid, which closes its ports. This pressurizes the hose, sending a pressure signal to the wastegate actuator. Whenever the wastegate actuator sees a pressure greater than its spring pressure it opens the wastegate to bypass some exhaust flow around the turbo turbine wheel and maintain turbo rpm (prevents further spoolup).

Sounds like you have a flow blockage somewhere, preventing that line from venting. Either the hose from the T to the boost control solenoid is clogged, or the ports in the solenoid are stuck shut. Try checking those.
 

·
Registered
Joined
·
554 Posts
It is probably just a plumbing problem. I have my Autometer guage hooked up in the same place as you do, off the stock BOV pipe with a nice big brass tee. When you put the tee together I hope you used plumbers tape on all screw points. I eliminated the tee hose off the turbo with a manual boost controller while plugging the hose than ran back to factory boost solenoid. You will not get vaccuum off that line, only the BOV line. When i am cruising on the highway I run close to 20 on the vaccuum side of the gauge, when under throttle I go up to about 15.5 PSI of boost. If all connections are good and secured with zip ties or whatever, pull out the boost gauge tee and hook it back up the way it was and see if it pulls better for you. Or you could have a bad gauge.

Ok, I didn't really help, but after a few beers I just like to ramble on.

Justin
 

·
Registered
Joined
·
292 Posts
Discussion Starter · #5 · (Edited)
here's my guage:


Austin, I think your explaination makes sense. My max boost is hovering right around 9psi. I've checked those hoses and they look good. So would the problem be on the ECU side or on the wastegate side? It's hard to say. Either way, this would be a dealership issue.

One more thing (this may be unrelated), but my cooling fan kicks on every 30seconds. When I start the car in the morning to get it warmed up, I am not even back to my front door and I can hear the fan kick on.

Root, yes I used that special glue crap on all my brass fittings. Granted, I have never installed a boost guage before but I think I got the install right.

Thanks to all for the help. I'll keep you posted on what happens. A Civic SI was messing with me last night and I could barely keep up with him. Something is definitely wrong. I was so embarrased.

-- Rich
 

·
Registered
Joined
·
292 Posts
Discussion Starter · #6 ·
FOUND THE PROBLEM!!!

I dropped my TurboXS MBC in to try to determine if it was the electronic boost control selonoid or the wastegate itself. It's the selenoid. Granted, I didn't tune the MBC just right the first time, but I got 13psi in 3rd. I did a few more tweeks and I'm now at 14psi.

I took the MBC back out and am now going to head to the dealership and point to the selonoid and say FIX IT!

Thanks for all the help. If we all lived closer, I'd buy a round of beers.

-- Rich
 

·
Registered
Joined
·
192 Posts
One more thing (this may be unrelated), but my cooling fan kicks on every 30seconds. When I start the car in the morning to get it warmed up, I am not even back to my front door and I can hear the fan kick on.
That is because you have the AC turned on and it's trying to get air across the AC condenser. Turn the AC OFF and it won't do that.

If your dealership is close, then, yeah, take it in. If not, try checking the hose that goes from that T to the boost control solenoid. There is a junction about halfway down the length of that hose that has a plastic restrictor in it. I have heard of these restrictors melting, and if it melted enough to clog the air path to the solenoid, you've found your problem.
 

·
Registered
Joined
·
292 Posts
Discussion Starter · #8 ·
It's 40 degrees here in the mornings... My A/C is definitely not on. I was watching it kick the fan on and off this morning again.

BTW, I did find some melted plastic pieces in the stock EBC hoses.

-- Rich
 

·
Registered
Joined
·
3 Posts
BigRich said:
here's my guage:


Austin, I think your explaination makes sense. My max boost is hovering right around 9psi. I've checked those hoses and they look good. So would the problem be on the ECU side or on the wastegate side? It's hard to say. Either way, this would be a dealership issue.

One more thing (this may be unrelated), but my cooling fan kicks on every 30seconds. When I start the car in the morning to get it warmed up, I am not even back to my front door and I can hear the fan kick on.

Root, yes I used that special glue crap on all my brass fittings. Granted, I have never installed a boost guage before but I think I got the install right.

Thanks to all for the help. I'll keep you posted on what happens. A Civic SI was messing with me last night and I could barely keep up with him. Something is definitely wrong. I was so embarrased.

-- Rich
Hey BigRich,

I have been having hte same issue with boost not going over 10psi. I have installed some of that after markert yellow vacuum hose, but recently I have learned that there is a valve in one of the factory vacuum lines so I'm going to change the hoses back and see if that fixes it. :mad:

The fan issue you are having can also happen by having the A/C set to front defrost. If you turn it to vent or turn the fan to 0 it will stop this.
 

·
Registered
Joined
·
161 Posts
BigRich said:
>> Melted pieces are never good!

Neither is a $25,000 sports car with no balls!:D

-- Rich
What are you talking about? This is a 4 door family Sedan :).
 

·
Registered
Joined
·
3,501 Posts
Yeah, Rich. I noticed a lot of patrol cars recently too. What's up with that?

I saw an honest-to-goodness FIVE cops on my 19 mile commute to work on Monday!

-Jim
 

·
Registered
Joined
·
292 Posts
Discussion Starter · #15 ·
I watch the news every morning and they've been saying that Holiday travel by cars is up some 80%. No one wants to fly. We had plans to fly to Chicago for Christmas. Those plans got cancelled quickly! I have an office in the State Department. Lately I've been trying to work out of my satelite office in Southern Maryland. I don't need Anthrax.

Who can I leave my car to in my will? ehehe

-- Rich
 

·
Registered
Joined
·
376 Posts
hmm

*Please note that the WRX is equipped with a factory electronic boost controller. The solenoid must be disabled in order for the TurboXS manual boost controllers to work properly*

i hope u did this because i was reading on turboxs site and i stumbled across this...
 

·
Registered
Joined
·
66 Posts
Big Rich,

I also noticed my cooling fan(s) coming on shortly after starting the car in the mornings. It really didn't click until I read your post. One of those memory triggers I guess. My A/C and defrost also both off. Anyone else out notice this?

Shawn
 

·
Registered
Joined
·
17 Posts
Ok This is my initial post on this type of chat room so bear with me if i am jacking something up here..

but a quick statement on my self and why I am here... I currently don't have a WRX. I have a 1998 Eagle talon tsi awd, (see pic) with some mods on it. (profec b, 3" exhaust, larger turbo, intake, gauges etc, etc..) well I have liked the WRX from the git go, and am a closet enthusiast for these cars. Not to mention that i have two buddies that just bought them, so i am learning alot quickly.

One bud has done the exhaust 3" from turbo back. (gets CE lights all the time) Intake, (injen) gauges, and profec b all of which i helped install.

the other bud is in the stock car getting ready to mod, and i will be helping him.

Ok with that said, i am replying to the post regarding the 9 lbs of boost issue. The one thing i experienced when a buddy and i installed a Profec B into his wrx, was that when we powered off the profec b the boost level only got to 8-9 lbs of boost also, which we both though was odd. we were under the impression that the stock boost on a wrx (2002 usa model) was in the 12-13 range. Is that correct? What IS the stock boost level? Well anyway, the reason i thought it was odd is because on my Eagle talon, when powering off my profec of it does go back to the stock 10.5 -11 psi boost. which leads me to believe the boost level you are experiencing on your car is a function of the wastegate spring tension. (does that make sense??) This also leads me to believe that there possibly is a leak in a vac line leading to the wastegate. which is causing the low boost level.

Just my $.02..

Thoughts anyone?
 

·
Registered
Joined
·
292 Posts
Discussion Starter · #19 ·
The problem has definitely been fixed. There are these plastic restrictors in the stock tube that goes from the turbo to the stock boost controller. This restictor MUST be on the turbo side. If it is on the wastegate side the wastegate isn't getting enough pressure and is always sprung. Bottom line was, I was only getting 9PSI of boost.

Dropping the MBC in brought me right back up to 15 where I wanted to be. However, yes, stock boost is 13.8 (or something close to that).

-- Rich
 
1 - 19 of 19 Posts
Top