possibly boost leak.....

fuzzybmx

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Mazda speed 3
possiable boost leak.....

Hello all! for about a week now I've been noticed my boost would hit up about to 16.5 psi then make its way down to 13 psi. It will do this mostly in 5th gear. At times it will hold at 16.5 psi in all gears, but most the time it will drop. I have a cp-e nano sri, test pipe, and AP running stage2 map. I changed out my OEM bov. but I'm not sure where to go from here. I would appreciate and advice. Thank you!!
 
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165 psi, you will blow it up!

What did you change it out with, another stock? Those things are crap. I got s Forge BPV and it hold boost well. You should check your hoses off the turbo to the intercooler, and to the throttle body. You have a leak somewhere, and those clamps can come loose.
 
My bad, I meant 16.5. I put on another stock BOV to see if it was that. I'll go check the hoses right now. thanks!
 
The hose in the back going to the turbo seemed a little lose. I haven't got a chance to take the car for a drive yet. In the morning I will. Are there any other hoses I should look at?
 
So I tightened down the hose clamps. They really didn't seem to lose. It sms like my boost is dropping down more in 5th gear. Is there anything else I can look at? I don't much about a turbo car. But I'm willing read and learn. I really want my car to run strong again.
 
So is it a hose that runs from the turbo straight to the throttle body? Could my waste gate be causing me problems as well? Thank you for the reply.
 
what if the inlet tube which i think connects to the turbo was a little lose, could that cause some problem for me?
 
Mostly driveability issues on that side of the turbo, as unmetered air is entering the intake.

Check the connections on the boosted side, those are the ones that work loose. Do this engine cold and make sure you get the lower ones as well, not just the top ones near the intercooler.
 
thanks for replying Darth Vader. Which side is the boost side? and to get the lower ones do i have to jack the car up?

Since I tightened down the inlet tube it seems to be better. could be in my head.
 
So is it a hose that runs from the turbo straight to the throttle body? Could my waste gate be causing me problems as well? Thank you for the reply.

No. The air comes out of the compressor side of the turbo up through a hot pipe at the back of the engine (it's a silicone tube at the back of the intercooler that reaches down to the turbo) and into the top-mounted intercooler (the thing under the black plastic engine cover) then into the TMIC cold pipe (where the BPV is mounted), down and into the intake manifold (through another silicone black tube), then engine.

Which side is the boost side? and to get the lower ones do i have to jack the car up?

Since I tightened down the inlet tube it seems to be better. could be in my head.

Boost side is the pipe coming out of the compressor part of the turbo, into the TMIC and then into the cold pipe and intake manifold. The intake side is where the intake and turbo-inlet-pipe hook up to; and the exhaust side is the downpipe coming off of the turbine. No, you don't have to jack the car up.

It could be in your head I guess... if there were drivability issues before while under any boost and there aren't any now, then yeah... you did something right.
 
I've been experiencing some baffling boost issues myself, and a friend of my just threw this idea out there. Is it possible the wastegate itself is leaking?
 
So I just checked the hose that went from the turbo to the tmic and it seemed like it could have been on tight. I noticed on the inner side it looked a little high. So I tightened it down. I will see tomorrow if it has made any difference. Is there anything else I can check?j.

I don't think its my drivability. I've never notice the boost this low before. I have a boost gauge and a ap. I can post some ap logs tomorrow.

I've also wondered if it could be a waste gate problem. I have heard any complaints on those. I've heard people say to swap the stock bov. Or is it called the bpv?
Silver do you have a boost gauge?
 
I run a Dashhawk for a Boost Gauge.

I've ran multiple different BPV's (stock, Forge, currently TS BPV) and the car still reacts the same. Spikes real high and settles down well below the stock targeted range. And it doesn't matter if it's 20*F or 80*F.
 
So after tightening the hose from the turbo to the TMIC there is no change at all.
I plan on check the wastegate vacuum lines tonight. I notice there is a hose on top and a hose on bottom. where does the bottom hose go from the wastegate?
 
here is a quick log i did from my AP on the way to work. this is just 5th gear.

According to your log, there are no boost leaks and the BPV is fine.

If there is a leak, the WG duty will be abnormally high (the boost pressure is lower than target and the ECU is trying to increase it).
In your case, the WG duty and boost pressure are tracking each other well.

The boost is pretty much where the ECU wants it to be.
 
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You should not be dropping boost that much, there must be a leak somewhere. I have not heard of a WG going bad but I guess it could. There was a guy on the boards recently that had boost issues and he swore up and down that he checked all the clamps and they were fine. He took his car to the dealer and they found a clamp loose that he forgot to tighten up when he removed his TMIC to install new plugs.

Check everything again. If you have a friend who is a gear head have him help.
 

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