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Boost gauge install gone wrong...help

5.8K views 31 replies 11 participants last post by  SilverSubaab  
#1 · (Edited)
So I installed a prosport boost gauge this afternoon in my 06 WRX. I start the car up and the gauge goes to like 15 vacuum, then goes down to 17. I go for a quick drive, just accelerating normally, and the it goes to like 5 vacuum, most of the time staying at 20 vacuum. I put the pedal down, and see something like 7 psi for a second or two, and then maybe 5 psi for a second. Back off on the throttle and I get 10-20 vacuum....? As well, I get a light sputtering hissing from the pass-through behind the pedals. What the heck did I do? For the boost line, I cut the BOV line and put the T in between, with the 2 ends in a straight line going in the middle of the cut factory line (which has very little line to work with). The lines are on as tight as I can get them, and I even used little hose clamps. Damn, why does there always have to be a problem......

**** - Update: I am updating the first post as the issue has changed and the post was moved. The boost gauge now reads correct, but the car is acting messed up. It does not want to accelerate, there is this rattling/fluttering/sputtering sound up to around 3,500 rpms. You push the gas and nothing. The car makes a lot of noise and does not want to go anywhere. The later post in this thread describe it more.... Any thoughts anyone?
 
#2 ·
SilverSubaab said:
So I installed a prosport boost gauge this afternoon in my 06 WRX. I start the car up and the gauge goes to like 15 vacuum, then goes down to 17. I go for a quick drive, just accelerating normally, and the it goes to like 5 vacuum, most of the time staying at 20 vacuum. I put the pedal down, and see something like 7 psi for a second or two, and then maybe 5 psi for a second. Back off on the throttle and I get 10-20 vacuum....? As well, I get a light sputtering hissing from the pass-through behind the pedals. What the heck did I do? For the boost line, I cut the BOV line and put the T in between, with the 2 ends in a straight line going in the middle of the cut factory line (which has very little line to work with). The lines are on as tight as I can get them, and I even used little hose clamps. Damn, why does there always have to be a problem......
your numbers sound right except for the sound there is a leak in the line somewhere
 
#3 ·
Your numbers do not sound right. You should be boosting more than 7psi. From the sound of it you probably put a hole in your line to the boost gauge and thats the noise you are hearing.

If you are hearing it from inside the cabin, have a friend blow into the end of the hose in the engine and you check if you can find anything.
 
#6 ·
No, I did not use teflon tape. I am going to try that this morning. Also, it seems like I have more delay in the throttle/lag since installing the boost gauge. I had someone hit the gas a bunch while I listened in the engine bay and could not detect any leaks. I checked the hose before I installed it and I have made sure it was not snagged or pinched in any way. I can still move it freely. I get noise(air sputtering/wooshing from the gauge as well). I would take the hose off and try again(maybe with a different hose) but my fingers are so sore from pushing the BOV hose on the T-fitting that I could not do it right now. I actually tore some skin away from from thumb-nails pushing/pulling the hose on....
 
#10 ·
vacuum from autozone. same size as the crappy see-through plastic stuff that came with the gauge( the hose was all kinked and pinched, so I decided to get something else).

The gauge works fine at this time. Put some teflon tape around fittings. It just feels like the car stumbles and lags a bunch now, that it does not pull as hard. The car definately did not stumble/accel. choppy before gauge install. This is so ridiculous ...
 
#12 ·
I used the T fitting that came with the gauge. The hose has the same size internal diameter, so this should not cause issues. Plus, the reason I did not use the one that came with the gauge is that it is all kinked and pinched due to the way it was packaged. I tried leaving it out for a couple of days to see if everything would flatten out (or actually un-flatten I suppose), but the line is still messed up. I just don't see why adding a damn boost gauge would cause the car to be slower?
 
#14 ·
Yep. The really messed-up part of it is that while I was trying to get the gauge to read right last night, the car felt great for most of the night, while the gauge was not reading right. Now it seems as though the gauge is reading right(I hit around 11-12psi for my 06 WRX), but the car does not seem to want to accelerate as quickly, hardly at all down low, where the 06 feels so much better compared to my 05 2.0L. The 06 now feels a little like the 2.0L down low with lag and choppy gain of speed.
 
#15 ·
SilverSubaab said:
Yep. The really messed-up part of it is that while I was trying to get the gauge to read right last night, the car felt great for most of the night, while the gauge was not reading right. Now it seems as though the gauge is reading right(I hit around 11-12psi for my 06 WRX), but the car does not seem to want to accelerate as quickly, hardly at all down low, where the 06 feels so much better compared to my 05 2.0L. The 06 now feels a little like the 2.0L down low with lag and choppy gain of speed.
Did you reset the ECU or change anything else?
 
#16 ·
Nope. I did nothing. It makes no sense.

This is probably a stupid question, but if I did have a leak from the boost gauge install, a leak in the T spot or the line going to the gauge, or anywhere that I touched, would it make the car slower?

...I think I need to get my butt to church, or find a 4-leaf clover, or just drink more....
 
#17 ·
Go and undo the T for the boost gauge, and put the lines to stock. Then go out and see if the car still fills the same or not. I really dont see how installing a boost gauge would make your car stumble. Make sure you didnt accidentaly mess something up.
 
#18 ·
I tried the small hose that came with the gauge; car drove like crap. I tried a brass T fitting that I made from Home Depot parts; car ran like crap. I took the boost gauge off and hooked up the factory hose; The car STILL drove like crap. Lag, push the throttle and the car does not really make any power, and a wonderful weird rattling/fluttering, hissing sound. So apparently hooking up a boost gauge has messed up my car. Any ideas as to how this could be or what this might be...

... if you'll excuse me, I'm going to go into the garage and shoot myself in the head.
 
#21 ·
possible try resetting the ECU? maybe it learned something bad from all the changes
 
#22 ·
I just took the negative terminal off the battery, tapped on the brake for a little, pushed the hazard button on, and left it like that for an hour or so. Hooked it back up and I have driven it about 29 miles since...No change...


There really can't be any leaks on the connections I have done. I have re-done them over and over several times this weekend. I currently have teflon tape on all the fittings, the hoses are pushed on as far as they go/I can, I have hose clamps on the connections and zip ties where I could fit both. I have changed out hoses to make sure that it was not a matter of size, or material, or having a hole/cut in the line running to the boost gauge. At this point, I am unfortunately about ready to drive to my local Subaru dealership and see what they think about the issue. Of course, I installed the gauge myself, and I have a catback on the car, as well as sway bars/braces...so who knows what they will say. I don't have the strength or time to take all the stuff off, especially when none of it really could have caused a problem.

It is just my luck around this kind of stuff. I was thinking last week how great my car was running and how much I enjoyed driving it. I was not looking to mess with/mod anything else. I found a good price on a boost gauge, that I always felt like it was a good idea to have and should have come standard in stock form, so I bought one. Simple, straightforward install. It is sad that it seems something always has to go wrong, that happiness and peace seem so elusive to me... I just want to drive my car and be able to have some sense of freedom from all the crap we have deal with each day, to just have a "pure" experience of driving, no one yelling at you, no phones going off, no money concerns, no relationship concerns, nothing....just driving...
 
#23 ·
So I took it to the dealership today. They were pretty good all in all, I just don't have an answer yet. They were able to confirm the presence of a noise before the turbo spools up completely, but say that they can't really do anything about it until it would get worse. They said that it sounded a little like air swirling around the intake. almost like I had an aftermarket intake on the car - I have the stock airbox, stock filter, etc.. They said there is enough variance in cars that this does not seem like an issue at this time. I still find the situation ridiculous and don't see why this would have all started because of a boost gauge install.

One thing I did think of: the hose that goes from I believe the intake manifold to the BOV that I cut to put the "T" in - could that have come out a little from manifold? How does it attach down there? I can't really see all that much and can't get my hand down there as it is pretty cluttered. In re-adjusting the line going to the boost gauge a couple of time, having to pull the T-fitting off twice(as I had to do in order to make sure that it was sealed tight), could that line have come loose? I can't see how it is attached. Could that cause the symptoms the car seems to be having?

I don't know, it is just a thought...
 
#25 ·
SilverSubaab said:
It does not want to accelerate, there is this rattling/fluttering/sputtering sound up to around 3,500 rpms. You push the gas and nothing. The car makes a lot of noise and does not want to go anywhere. The later post in this thread describe it more.... Any thoughts anyone?

Sounds like the BOV is messing up.
 
#26 ·
Went to AutoZone yesterday and bought some new hose to run from the manifold to the BOV. I am going to try to replace it tonight, but might have to wait until Thursday. I'm leaving the boost gauge off.

I have checked under the hood and under the dash as best I could to make sure that nothing came loose or off while installing the gauge.

One thing I noticed yesterday and today is that under light throttle to maybe 1/2 or 1/3, I get regular response and good acceleration(for the amount of gas I;m giving it). It is only when I go from vacuum to asking the turbo to push a good amount of boost that I hear the noise loud and clear, and the car lags and does not want to get going. The higher rpms have better results (4-6,000) but still seem to stumble and not pull as hard as it did before this issue began. I don't know, sounds like a leak, I just can't find where or understand why this would have happened with just a boost gauge install.

As mycologist suggested, I am really wondering if the BOV is messed up...

Thanks for the continued support around this issue!