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boost leak test

20K views 90 replies 18 participants last post by  blkspd3 
#1 ·
ok so i assembled a leak tester yesterday using a 2" pvc cap and a valvestem.... $4.00 total.
it did its job just fine, but my results are ....... inconclusive. first i tested it from where the reducer goes on the inlet side of my MS intake. this method would pressurize the entire boost system, including the turbo and all the little vac. lines that come off of it. i pressurized to 25psi, and found a small leak where the plastic intake tube clams on the turbo. this would not be a boost leak, since it is on the intake side. i did tighten it up just for good measure though. i then proceded to put the tester right befor the throttle body to get a maor accurate manifold pressure test. i again used my compessor to pressurize to 25 psi. i did see that gauge was showing the pressure rapidly droppping, and i heard a rushing air sound. so i filled a spray bottle with soapy water, and pulled the IC off (i was only testing the manifold and hoses leading from it at this point) after several spray downs i found only a tiny leak right at the TB and only above 22psi, so i know that is not my problem. i still hear the air coming out somewhere, but it may just be passing through the engine.
i reset the battery and drove for a while i still see lower boost levels than i used too.
i see;
10psi in 1st
13 in 2nd
13 in third
14- 15 in 4th
5th and 6th will hit 16 and hold 14
did anyone else test or leaks yet ??
if not will someone try it and same their results ?? i would like to see if you hear the same thing or if i do infact have a leak.
i dont want to bring it in to the dealer and leave it for a few days just for them to tell me its fine.
 
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#3 ·
How exactly are you making the whole system air tight? Air is going to leak out from the throttle plate as that's not going to be a 100% air tight. Maybe make sure the engine cylinder 1 is at Top Dead Center, that should line up all the cylinders either at the top or at the bottom with all the intake valves closed.
 
#5 ·
[quote author=eurotuner link=topic=85432.msg1619574#msg1619574 date=1186524485]
a question for you guys

no matter what bolt on u install, do you still run the same number of boost?
[/quote]
the 17mm bolt give 17 pounds of boost. The 19mm bolt gives 19 pounds.









:D
 
#7 ·
[quote author=eurotuner link=topic=85432.msg1619592#msg1619592 date=1186524824]
oh and how do u change that !?

on the WG?
[/quote]
Sorry - did you see the smiley? There is nothing simple you can change. The ECU controls everything.
 
#9 ·
[quote author=eurotuner link=topic=85432.msg1619609#msg1619609 date=1186525192]
no i didnt

but u should be able to change twist the screw on the waste gate...
no?

i am just been curious
[/quote]
No, you can't. The waste gate limits to about 10psi. The ECU overrides limit to about 18 when it feels it is safe. If you change the spring it changes the basic boost, but the ECU is really in control. In fact, if the ECU detects the base boost higher than it is supposed to be, it may shut down the engine with a fuel cut.
 
#11 ·
[quote author=bombermanx link=topic=85432.msg1619474#msg1619474 date=1186522523]
How exactly are you making the whole system air tight? Air is going to leak out from the throttle plate as that's not going to be a 100% air tight. Maybe make sure the engine cylinder 1 is at Top Dead Center, that should line up all the cylinders either at the top or at the bottom with all the intake valves closed.
[/quote]
it is supposed to go through the throttle plate. air still gets through when the blade is shut, thats how your car idles !
i never did a test on any of my other turbo cars...never needed to. it dont know if i have a leak or if it is just the crazy hot humid weather we are having for the past few weeks. maybe the ecu is pulling boost due to the heat/humidity...???
 
#12 ·
[quote author=TRU-BOOST link=topic=85432.msg1615486#msg1615486 date=1186414303]
ok so i assembled a leak tester yesterday using a 2" pvc cap and a valvestem.... $4.00 total.
it did its job just fine, but my results are ....... inconclusive. first i tested it from where the reducer goes on the inlet side of my MS intake. this method would pressurize the entire boost system, including the turbo and all the little vac. lines that come off of it. i pressurized to 25psi, and found a small leak where the plastic intake tube clams on the turbo. this would not be a boost leak, since it is on the intake side. i did tighten it up just for good measure though. i then proceded to put the tester right befor the throttle body to get a maor accurate manifold pressure test. i again used my compessor to pressurize to 25 psi. i did see that gauge was showing the pressure rapidly droppping, and i heard a rushing air sound. so i filled a spray bottle with soapy water, and pulled the IC off (i was only testing the manifold and hoses leading from it at this point) after several spray downs i found only a tiny leak right at the TB and only above 22psi, so i know that is not my problem. i still hear the air coming out somewhere, but it may just be passing through the engine.
i reset the battery and drove for a while i still see lower boost levels than i used too.
i see;
10psi in 1st
13 in 2nd
13 in third
14- 15 in 4th
5th and 6th will hit 16 and hold 14
did anyone else test or leaks yet ??
if not will someone try it and same their results ?? i would like to see if you hear the same thing or if i do infact have a leak.
i dont want to bring it in to the dealer and leave it for a few days just for them to tell me its fine.

[/quote]

I know where the leak is and we are working on a fix for it. Should be released soon.
 
#13 ·
why kind of post is that ??!!!
are you trying to tease me on purpose ??
you should share your findings ....
 
#18 ·
[quote author=bombermanx link=topic=85432.msg1619474#msg1619474 date=1186522523]
How exactly are you making the whole system air tight? Air is going to leak out from the throttle plate as that's not going to be a 100% air tight. Maybe make sure the engine cylinder 1 is at Top Dead Center, that should line up all the cylinders either at the top or at the bottom with all the intake valves closed.
[/quote]

Even putting the #1 at TDC does not mean that all the intake valves are closed.
 
#21 ·
as soon as the product comes out, we can see how it works anyways.....
we can then buy it or come up with our own fix. the fact that PTP hasnt posted since, makes me think its a bluff. they have no idea, just trying to sell something. my guess is it will be some sort of crank vent type thing.
 
#22 ·
[quote author=TRU-BOOST link=topic=85432.msg1648954#msg1648954 date=1187389787]
as soon as the product comes out, we can see how it works anyways.....
we can then buy it or come up with our own fix. the fact that PTP hasnt posted since, makes me think its a bluff. they have no idea, just trying to sell something. my guess is it will be some sort of crank vent type thing.
[/quote]

Not a bluff and we are working on finding the correct size part for the fix. The PCV valve appears to leak under boost just like all other turboed cars. We have a solution for other turbo cars but the MS3 is giving us some issues due to the location. Yes a crank vent type thing, I will have the results up in 2 to 3 weeks.
 
#23 ·
did i call it or what ?!?!?
let me know when its ready.... it should be a reasonably cheap mod and easy to do. lord knows this little turbo cant afford a leak....of any size !
 
#24 ·
[quote author=TRU-BOOST link=topic=85432.msg1662835#msg1662835 date=1187833431]
did i call it or what ?!?!?
let me know when its ready.... it should be a reasonably cheap mod and easy to do. lord knows this little turbo cant afford a leak....of any size !
[/quote]

yea you did. subscribing.
 
#25 ·
+1
 
#26 ·
Update on the fix. Stil looking for the damn fitting that I need. I may end up doing something different with the check valve to keep the PCV system from leaking but for now the mod I have is very simple if I can find the fitting. We also have seen some interesting gains by getting rid of the vent from the VC to the intake tube. There appears to be a lot of hot oil fumes under the valve cover that love getting sucked into the turbo inlet. I will have a simple how to or fix it kit for that as well.
 
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