How to find a boost leak

[djuosnteisn]

Hahahahaha, someone beat me to it then.

[Matrix311]

Well just bought all the parts and ran a boost leak test, instantly i hear some hissing sounds. The first and loudest one I located was along the weld of my CP-E CAI just around the MAF housing. Your right Dustin, i have a small hair pin hole like what you pointed in the pictures and a ton of air is really moving through there. I just tossed on some JB Weld so hopefully after that takes care of that leak. Once that cures i'll run another test to see if there are any more leaks. Thanks for the thread and part listing! Cost me $20 from Ace for all the parts, they had everything there I needed.

[djuosnteisn]

Good catch. Even though the intake will never be under boost, a hole there is both unfiltered and unmetered air getting in, and should be fixed.


I'm gonna do a boost leak check today maybe

[8.5MS3]

well i got the system to 15psi or so....

no audible leaks in the intake/fmic piping

opened the drain to my occ, no air out of there either, so both pcv's are holding

only spot where air gets out is the valvecover breather

i didnt dare lift the dipstick for fear of moar oil ejaculation

i iz officially confuzzled

btw after the test i threw 2 codes, crankshaft position sensor (lol) and barometric pressure sensor.

the latter i understand, but the crank is a head scratcher

cleared them, nothing returned

[Matrix311]

Originally Posted by 8.5MS3 well i got the system to 15psi or so.... no audible leaks in the intake/fmic piping opened the drain to my occ, no air out of there either, so both pcv's are holding only spot where air gets out is the valvecover breather i didnt dare lift the dipstick for fear of moar oil ejaculation i iz officially confuzzled btw after the test i threw 2 codes, crankshaft position sensor (lol) and barometric pressure sensor. the latter i understand, but the crank is a head scratcher cleared them, nothing returned

I had the same problem. I was getting air coming out of my valvcover breather as well and I also threw those codes, cleared my AP and they have not returned. I just drove 50 miles and no issues that I could tell.

Originally Posted by djuosnteisn Good catch. Even though the intake will never be under boost, a hole there is both unfiltered and unmetered air getting in, and should be fixed. I'm gonna do a boost leak check today maybe

Ya good call, I guess I never thought about that. Either way I had 2 other clamps that were loose which I tightened and it made a world of a difference. I was getting a bunch of kr and my AFRs were all over the place. After fixing the 2 clamp leaks my AFRs are super stable and i'm registering zero kr on wot 3rd and 4th gear pulls. Thanks for reposting this how to.

now I just need to plug my recirc bpv hose so I can test to see if my hks ssqv is leaking or not.

[djuosnteisn]

Originally Posted by 8.5MS3 well i got the system to 15psi or so.... no audible leaks in the intake/fmic piping opened the drain to my occ, no air out of there either, so both pcv's are holding only spot where air gets out is the valvecover breather i didnt dare lift the dipstick for fear of moar oil ejaculation i iz officially confuzzled btw after the test i threw 2 codes, crankshaft position sensor (lol) and barometric pressure sensor. the latter i understand, but the crank is a head scratcher cleared them, nothing returned

I tested my setup yesterday... and same thing... air (smokey air in my case cause engine had just been running and was still very hot) coming out the valve cover.

It's normal IMO. There's always an open valve, and air will creep past the rings etc... As long as your compression is good, then there's no problemo. You just need a pressure source capable of filling the intake tract fast enough.

Oh, and oddly enough........ i thread the crankshaft pos sensor cel as well. Interesting hahahahahaha.

[urville]

Originally Posted by 8.5MS3 seeing as the valvecover breather is after the maf, in theory there should be no change to the maf calibration but if 10% of the air is simply flowing from the intake mani -> crankase -> the intake and around again, then the fueling would be rich since that portion of the air is running around in circles whats worse is that potentially means that the turbo is spinning like a fucking lunatic trying to hit boost targets with a bypass in the system....and your pressurizing the crankcase or im absolutely 100% wrong....idk im gonna go drink and mow this over in my head

So... wait... in comparison to older threads, could you in fact just vent through a breather filter without causing issues? Because that air is unfiltered and carries garbage in it. If I understand right it sucks under throttle and vents during low throttle/idle... maybe thats totally wrong. most tshit i can find on the PCV system omits real depth on the valve cover breather, to only say, its venting. this would be great cause it would cost me one less occ

[djuosnteisn]

I vent mine to atmosphere. You'll just have to re cal the maf.


Under vac, the system works like this. Vacuum from the intake manifold sucks air in from the turbo inlet, to the valve cover, down the timing chain cover, into the crank case, out the crank case breather, through a PCV valve (which limits the amount of air flow) into the intake manifold.

So you have a constant and continuous "breeze" so to speak through the crank case into the intake mani, and thus out the exhaust. These breeze is important to pull the blow-by nastiez out of the crank case and burn em off in the motor, and helps preserve the oil life.


Under boost. The PCV shuts (like a check valve).... so any crank case pressure can only vent out the valve cover, into the turbo inlet.




With all that said... and with the goal of limiting the amount of crud sucked into the motor.... the best setup for a bolted speed is probably a filter on the valve cover, and a catch can off the pcv to the intake. When in vac, the OCC (catch can) will catch the nastiez.... and under boost, they will be vented out the filter (but not into the turbo / intake.


You could also run an OCC on the valve cover, and still route it to the turbo inlet. This is a nice setup cause the turbo inlet is actually in vacuum under high loads, and will help limit the pressure in the crank case better than a VTA filter.




I'm gonna be trying something a bit more exotic in the near future. And if it works out well, i may make a kit out of it for everyone. If it works, it'll result in zero nastiez going back into the intake, all the time.... and double the venting under boost.

[8.5MS3]

i had something like that way back when. it totally fucked up my trims lol

http://www.mazdas247.com/forum/attac...2&d=1246546466

huge pic is huge

[djuosnteisn]

I like it. Worth a maf cal IMO.

[8.5MS3]

i actually welded a post to the bottom and used the airbox mouting hole to support it.

pretty clever for a retard like me

let me know when im next for a recal and ill throw it in before logging

just gotta find the end of the broomstick i used to plug the intake lol

[SLOWHATCH]

Sorry if this is a newb question, but when I do this should I attach the tester to the maf housing? Or directly to the TIP?

Maybe it makes no difference but wanted to make sure. I'd rather not have to remove the maf housing if unnecessary.

[silvapain]

Pull off filter, attach tester.


Tapadatass

[SLOWHATCH]

Ok so I tested my car and I have no leaks. However some air was escaping from valve cover also. I disconnected the breather hose from tih and plugged it but didn't have anything to plug the vc with. Got the system up to 22 psi though with no leaks anywhere else.

I will say the 3 to 2" reduced was too big to use with my cs intake so I had to improvise. Were these instructions made for a bt car?

[djuosnteisn]

Na, it was used on a cp-e CAI. I just scrunched the shit out of the rubber coupler to "make it fit" lol.

[myt_tuf1]

Originally Posted by SLOWHATCH Ok so I tested my car and I have no leaks. However some air was escaping from valve cover also. I disconnected the breather hose from tih and plugged it but didn't have anything to plug the vc with. Got the system up to 22 psi though with no leaks anywhere else. I will say the 3 to 2" reduced was too big to use with my cs intake so I had to improvise. Were these instructions made for a bt car?

A 2" to 2" coupler works great... With the CS SRI at least.

[silvapain]

I bought a Spectre coupler from
Autozone for mine; it comes with a 3x2.5" reducing insert that works perfectly with my CP-e SRI.

EDIT:

This is it
http://www.autozone.com/autozone/acc...er=601098_0_0_


Tapadatass

[8.5MS3]

i used a 4x3 reducer for my cobb sri

[Pedal-Force]

Originally Posted by myt_tuf1 A 2" to 2" coupler works great... With the CS SRI at least.

So I tried to do this today and ran into some problems. I ended up making things complicated, and bought a 3" PVC cap, a short piece of 3" PVC Pipe, and various air fittings and barbs to make it work.

I did all this thinking that when CS says in the instructions that their angled intake hose is 3", they mean ID, but they actually meant OD. So my 3" PVC pipe doesn't fit in there. Are you saying a 2" rubber coupler will connect to the CS TIP correctly if I remove the angled intake hose first? Then I could just get a 3" to 2" coupler, put the 3" side on the PVC pipe, and the 2" side on the TIP.

I now have everything all cemented and puttied together, so I can't really take my fittings back out and I'm kinda stuck using the 3" PVC pipe, and I need a way to attach it to the car.

[myt_tuf1]

Originally Posted by Pedal-Force Then I could just get a 3" to 2" coupler, put the 3" side on the PVC pipe, and the 2" side on the TIP.

Wow, you really did make things complicated. ^This sounds like it will work, just take off your filter, maf housing, and silicone elbow, and attach 2" side of coupler to TIP (it'll fit fine, but if it's a little tight, use some silicone spray or white lithium grease, and it'll slide right on) and tighten your PVC pipe down in the 3" side.

Good luck, and don't forget to take off your valve cover breather hose and plug it up while you're testing.

[ColonR]

here for those of you that dont have a drill that you can use to drill the pvc cap i found a different way to build the boost leak tester using similar parts but not exactly the same. here youll need the 3in to 2in rubber reducer and thiis pvc cap with the 1/2in threaded hole then also the 1/2 barbed piece that will screw in the top.

[silvapain]

Or, you could have looked at how I did it on page 1 and seen a threaded plug used...


Tapadatass

[ColonR]

haha true i couldve but i didnt even see your post i went to lowes to get the stuff to take djs design and made that one up as i was there good idea though

[Meder]

Boost leak test had air coming from here. This is around 15-16 psi connected directly to the maf housing. Any idea why? Oil came from here as well.

[myt_tuf1]

Originally Posted by Meder Boost leak test had air coming from here. This is around 15-16 psi connected directly to the maf housing. Any idea why? Oil came from here as well.

Yes, you didn't unplug your valve cover breather hose from the valve cover before you did the leak test.

There is a hose that runs from your intake (past the MAF, towards the turbo) that runs right up to your valve cover... Unplug that hose from the valve cover, plug the hose, or clamp it with something, and retest.

With that hose intact, you were pressurizing your engine, causing the air to come out from that specific spot.

[Meder]

Originally Posted by myt_tuf1 Yes, you didn't unplug your valve cover breather hose from the valve cover before you did the leak test. There is a hose that runs from your intake (past the MAF, towards the turbo) that runs right up to your valve cover... Unplug that hose from the valve cover, plug the hose, or clamp it with something, and retest. With that hose intact, you were pressurizing your engine, causing the air to come out from that specific spot.

Thanks, any harm done? I was already at my psi i run(16), do i need to retest? Its the only place that leaked so far.

[myt_tuf1]

Originally Posted by Meder Thanks, any harm done? I was already at my psi i run(16), do i need to retest? Its the only place that leaked so far.

Nope, no harm done afaik... And if there were no other leaks, you should be good to go.

[Meder]

Thanks

[Meder]

Found a leak near maf sensor. This leak is coming from the o ring on the maf sensor and starts to leak within 1 psi.

The o ring itself is a bit damaged, possibly from maf cleaner drying it out? its a bit shredded on one side. Since the intake isn't pressurized, does this even matter? Is it possible that unmetered air is getting in despite there be no pressure in the intake?

Anyone else get leaks around maf sensor when doing a boost test? Another thing, I had leaks all around the block that the maf bolts into on the cpe nano awhile back. From what i understand this does not really matter. Why would it matter if the maf had a small leak near it assuming it does not suck in air through that area?

Excuse my dumb questions. I don't quite have the knowledge that many of you have

[myt_tuf1]

Originally Posted by Meder Found a leak near maf sensor. This leak is coming from the o ring on the maf sensor and starts to leak within 1 psi. The o ring itself is a bit damaged, possibly from maf cleaner drying it out? its a bit shredded on one side. Since the intake isn't pressurized, does this even matter? Is it possible that unmetered air is getting in despite there be no pressure in the intake? Anyone else get leaks around maf sensor when doing a boost test? Another thing, I had leaks all around the block that the maf bolts into on the cpe nano awhile back. From what i understand this does not really matter. Why would it matter if the maf had a small leak near it assuming it does not suck in air through that area? Excuse my dumb questions. I don't quite have the knowledge that many of you have

It doesn't matter if anything is leaking pre-turbo (as far as loosing boost, because that area is never pressurized, or holding boost); however, as DJ mentioned earlier in the thread:

Originally Posted by djuosnteisn Even though the intake will never be under boost, a hole there is both unfiltered and unmetered air getting in, and should be fixed.

So I would find a way to seal that up, or see if you can buy a new o-ring from the dealership.

[DONOTBUGME]

soo would this method be better than @Derek Doo vacuum tube, bike pump, and cigarette smoke leak tester?

how to find boost leaks, guaranteed

[breakfstincluded]

Originally Posted by coltonR here for those of you that dont have a drill that you can use to drill the pvc cap i found a different way to build the boost leak tester using similar parts but not exactly the same. here youll need the 3in to 2in rubber reducer and thiis pvc cap with the 1/2in threaded hole then also the 1/2 barbed piece that will screw in the top.

I cannot for the life of me find a 1/2in barbed piece that will go onto a blow gun handle or otherwise connect to my compressor... 1/2inch seemes to be too big.

But I can't turn back now because my device looks just like yours now

[silvapain]

Originally Posted by breakfstincluded I cannot for the life of me find a 1/2in barbed piece that will go onto a blow gun handle or otherwise connect to my compressor... 1/2inch seemes to be too big. But I can't turn back now because my device looks just like yours now

Get a 1/2" NPT to schrader valve adapter. I got mine at Ace Hardware.


Tapadatass

[ColonR]

Originally Posted by breakfstincluded I cannot for the life of me find a 1/2in barbed piece that will go onto a blow gun handle or otherwise connect to my compressor... 1/2inch seemes to be too big. But I can't turn back now because my device looks just like yours now

hmm really?? thats odd my buddy and i ran it just push the chuck from the air compressor into the hose ha ha and use an oring to make sure its tight

[breakfstincluded]

I ended up just using a few adapters to get from the 1/2inch barb to a check valve, as guided through it by the Ace hardware dude.

My device must not be tight enough though because it keeps popping off at 11psi...

which is funny because that's where my boost pressure is max-ing out at which is leading me to check for leaks in the first place....

Anyone have any similar experience or should I just be tightening the coupler onto my intake tighter.

I'm also releasing the air into the intake very very slowly.

[breakfstincluded]

JBWeld, Awesome.

Tighteng better on intake, awesome.

Re-tightening MAF sensor because uneven tightness makes it tilt and leak, awesome.

Compressing to 15psi and getting air out of the VVT actuator on VC, not awesome.

Will try disconnecting valve breather hose on the intake and also reciculation hose on BPV. But how the hell are you guys capping these things off? Potato?

[silvapain]

Length of hose folded back on itself and hoseclamped down.


Tapadatass

[breakfstincluded]

Will try that on recirc hose.... And just take off the damn SRI to pressurize at TIP.

Hopefully I won't have to remove my battery, I need that so I can monitor boost on AP lol

Also: sounds like what the bad guy in silence of the lamb does to his nuts in front of the mirror and dances.

[JP@edgeautosport.com]

Was thinking at first that the PCV hose leak under pressure was because most of you guys probably pressure test higher than what stock boost is from Mazda but then @08.5MS3 said he did 15psi and it still happened. I'd bet that any internal components seal better when expanded from heat while running causing that issue to go away or at least be reduced under circumstances where the PCV isn't venting.

Just a thought
@djuosnteisn

[jack_hammer]

if your pcv is leaking, then you will see air come through the valve cover vent.
if your bpv is leaking, you'll see air come out of there.

those both recirculate.

so if you want to see only if you're losing air out of the system, then you could leave those in place. then, you could address any potential BPV and PCV leaks after.

is that correct?