From out of nowhere surge!?!?

S

schmitty

Member
:
'08 MS3
I originally posted this on Mnmazda, but I have kinda hit a wall in diagnosing this so your feedback is welcome.

Last week I upgraded my inlet and added a boost gauge. Everything ran well on Saturday and Sunday. Yesterday I take the car out in the morning and it runs fine. I go out in the afternoon , everything is fine on the way to lunch. On the way home while getting on the highway, I accelerated down the ramp (15PSI boost) clutch to shift and it sounds like I have a turkey in my engine, then the BPV makes it's mario coin sound. This continues every time I boost more than 5 or so PSI.

I come home, and change the spring in the BPV (was blue with no shim, so I swap to yellow with no shim) and no more turkey sound but, it wont hold very much boost.

Today it surges again and i check all the hoses I can without removing the battery box. AFAICT all the hoses are on and in good condition. The hose coming off the BPV (the big one) is on but is easy to slide off with out moving the clamp. I also saw that the tube going to the boost gauge solenoid is pinch so I freed it up. Rev the engine and BPV works fine a low boost, go out and test drive, anytime i get above 5PSI it gobbles, then the the BPV *chings*

So I am thinking that the BPV isn't operating fast enough, which could be remedied by using the softer yellow spring, but then it won't hold the proper amount of boost.

So far I have tried all spring and shim combos, and swapped with a known good Forge BPV. I also upgraded the clamps on the BPV and inlet.

Here is a video I made of what it sounds like. Any feedback is welcome. http://tinyurl.com/n2tmr3
 
how old is your BPV? Does the valve still open smoothly and easily by pushing it? You may just have to clean it up and lube it up again.
 
Are you saying that you tried another Forge and it did the same thing?

If so, it's got to be in the tubes and clamps somewhere.

If you have not substituted a known good BPV, do you still have your OEM BPV sitting around? Substitute it to see if the problem goes away. If problem is then solved, either leave it on or get a new, good Forge.
 
At first I thought it was just flutter, but that does not sound anything like my old forge sounded. I'm sorry but I would check all connections again as to me that does sound like Surge a bit to me.
 
Last edited:
We checked the connections at least twice... they all appeared okay.

One thing I was suggesting is that he said the BPV connection on the TIP (you installed that the same weekend too, right Schmitty?) is located closer to the actual turbo inlet than stock. So I was wondering if the recirculated air from the BPV was causing turbulence at the compressor inlet, and if that was the source of the surging.
 
I went through and reinstalled the inlet. Double checked all lines, tightened all clamps. Still surging.
 
MSMS3 said:
If you have not substituted a known good BPV, do you still have your OEM BPV sitting around? Substitute it to see if the problem goes away. If problem is then solved, either leave it on or get a new, good Forge.
Click to expand...

Try that.
 
I might be worth it to go VTA just to see if it stops the surging. That would answer the question of if the BPV being closer to the Turbo makes a difference. You will need to cap off the recirc hose to do this.

Shy of that, I don't know what to tell you. With your mods and the Forge you should easily be able to run the blue spring with 1 shim even.

Is there any chance something got dropped into the turbo with the Inlet install? I find it strange that it ran just fine for a day or so then started surging.

Have you checked and tightened all the clamps on the hot side to the throttle body to ensure your not leaking there? Not sure if that would make it surge but maybe?!
 
Bravnik said:
I might be worth it to go VTA just to see if it stops the surging. That would answer the question of if the BPV being closer to the Turbo makes a difference. You will need to cap off the recirc hose to do this.

Shy of that, I don't know what to tell you. With your mods and the Forge you should easily be able to run the blue spring with 1 shim even.

Is there any chance something got dropped into the turbo with the Inlet install? I find it strange that it ran just fine for a day or so then started surging.

Have you checked and tightened all the clamps on the hot side to the throttle body to ensure your not leaking there? Not sure if that would make it surge but maybe?!
Click to expand...

Single piston recirc valves can't be run VTA. They will be open whenever the manifold is in vacuum and you will have the mother of all leaks.
 
schmitty said:
I originally posted this on Mnmazda, but I have kinda hit a wall in diagnosing this so your feedback is welcome.

Last week I upgraded my inlet and added a boost gauge. Everything ran well on Saturday and Sunday. Yesterday I take the car out in the morning and it runs fine. I go out in the afternoon , everything is fine on the way to lunch. On the way home while getting on the highway, I accelerated down the ramp (15PSI boost) clutch to shift and it sounds like I have a turkey in my engine, then the BPV makes it's mario coin sound. This continues every time I boost more than 5 or so PSI.

I come home, and change the spring in the BPV (was blue with no shim, so I swap to yellow with no shim) and no more turkey sound but, it wont hold very much boost.

Today it surges again and i check all the hoses I can without removing the battery box. AFAICT all the hoses are on and in good condition. The hose coming off the BPV (the big one) is on but is easy to slide off with out moving the clamp. I also saw that the tube going to the boost gauge solenoid is pinch so I freed it up. Rev the engine and BPV works fine a low boost, go out and test drive, anytime i get above 5PSI it gobbles, then the the BPV *chings*

So I am thinking that the BPV isn't operating fast enough, which could be remedied by using the softer yellow spring, but then it won't hold the proper amount of boost.

So far I have tried all spring and shim combos, and swapped with a known good Forge BPV. I also upgraded the clamps on the BPV and inlet.

Here is a video I made of what it sounds like. Any feedback is welcome. http://tinyurl.com/n2tmr3
Click to expand...

My guess is that the cap o-ring has failed and the upper portion of the valve can't hold enough vacuum to keep the valve open. This is causing the piston to open and close rapidly and making the "turkey" sound.

Perform the "pent-test" in this PDF and let me know what happens.
 
I kinda have the same thing going on, every time I hit boost it makes this fluttering sounds, I have the PG Turbo inlet, COBB SRI, and a Type S BPV. I thought it was just noise of the air going through the TIP because it's stainless steel, but now I am worried that it might be surging and I know that can hurt a turbo.
 
i know a few different people including me that have funny sounds with the turbo inlet. i have the same set up....sri, turbo inlet, and forge bpv and mine makes what sounds like a sort of surge but i think it comes with the inlet. not surge....just the wierd noise. a friend in the ms6 section has an inlet and his makes a funny noise too. mine is sort of covered up by the mario coin but his is not because he doesnt have the forge.....food for thought. maybe it is surge and this needs to be figured out soon....OR ELSE!
 
I know the sound you speak of....its just a louder deeper sound of the BOV releasing. i took my car for a ride and duplicated it perfectly.
 
Last edited:
Thanks for all the good feedback everyone, getting this type of help makes me glad I am in the Mazda family.

Another update - I removed the hose going to the boos gauge and replaced the T with a regular two ended connector, still has the same problem.

I will try the "pent-test" as soon as patty fixes the link.

I kinda have the same thing going on, every time I hit boost it makes this fluttering sounds, I have the PG Turbo inlet, COBB SRI, and a Type S BPV. I thought it was just noise of the air going through the TIP because it's stainless steel, but now I am worried that it might be surging and I know that can hurt a turbo.
Click to expand...

The sound that you hear while at boost is most likely added noise from the inlet. My problem is when i try to get off boost. I really think the sound you are hearing is normal.

mazdaspeed32007 said:
I know the sound you speak of....its just a louder deeper sound of the BOV releasing. i took my car for a ride and duplicated it perfectly.
Click to expand...

Yes when it was working it was def louder, but after 3 days it when from being "cool loud" to "WTF why is there a turkey in my engine?"

Is there any chance something got dropped into the turbo with the Inlet install? I find it strange that it ran just fine for a day or so then started surging.
Click to expand...

Good Lord, I pray that didn't happen. At this point if something were to have been in there it would have made its way through the whole system several times. I was extremely careful and the only thing that may have gotten in there would be some silicone from the coupler and then only if the turbo or inlet sliced a piece off when i was sliding it in place., which would be very, very hard to do. I made sure to make sure there was no debris in the inlet before I installed it.
 
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