some boost leak test Qs

[tips000]

i have never done anything like this before... i understand that i put the tester on the inlet of the turbo and pump it with pressure...

i read somewhere that mbc will leak and are supposed to?? is that true? and if so how do i find other leaks?

will this help find vaccum leaks?

do i need to hold the throttle open?

i plan on using soapy water and a pc. of hose for finding leaks...

any other tips?

thanks

 

[BigBeans]

i have never done anything like this before... i understand that i put the tester on the inlet of the turbo and pump it with pressure...

i read somewhere that mbc will leak and are supposed to?? is that true? and if so how do i find other leaks?

Clamp the line to the MBC with vice grips or something similar

will this help find vaccum leaks?

Yes

do i need to hold the throttle open?

No

i plan on using soapy water and a pc. of hose for finding leaks...

any other tips?

Turn the crank to 30* ATDC so the intake valves are closed

thanks

Good luck!

 

[9!'clipseDOHC]

Yes, you can hook it up to the turbo inlet (to test the entire system) or the throttle body elbow (to test half of the system).

Yes, a MBC will leak, you need to clamp the line leading to the MBC. The other leaks you will find spraying connections and looking for bubbles.

Boost leaks and vacuum leaks are one in the same. A boost leak test will find both.

No, you do not need to hold the throttle open.

Tips? Use an air compressor with a regulator set to 20psi. Start at the TB elbow and work your way back. Check all vacuum lines, couplings, welds, injector seals, TB shaft seals, TB gaskets, etc. Works best with 2 people, one pressurizing the system and the other spraying and looking for leaks. Once you find a leak, fix it and repeat the test. Keep doing this until it holds your desired pressure.

Hope this helps!

 

[BigBeans]

^^ Beat you

 

[9!'clipseDOHC]

^^ Beat you

I noticed Guess I should have given little one word answers like you did.

 

[tips000]

I noticed Guess I should have given little one word answers like you did.

OHHHHHHHH haha jk

thanks alot guys i also found a tech article that helped alot that i didnt see before... also it seems like the bov will leak? i mean wont it blow off at 12 psi like i have have it set to?

i planned on having someone in the car watching my boost gauge and using a really cheap electric compressor and cycling it to keep the pressure up

and is it possible to do this withot being at 30*? i dont know how to get it there with the tools i have

 

[BigBeans]

I noticed Guess I should have given little one word answers like you did.

That's one of the many reasons why you're the wiseman

OHHHHHHHH haha jk

thanks alot guys i also found a tech article that helped alot that i didnt see before... also it seems like the bov will leak? i mean wont it blow off at 12 psi like i have have it set to?

i planned on having someone in the car watching my boost gauge and using a really cheap electric compressor and cycling it to keep the pressure up

and is it possible to do this withot being at 30*? i dont know how to get it there with the tools i have

No, the BOV shouldn't leak at 12psi. Don't clamp the line to the BOV and it should hold a lot more than 12psi.

All you need is a 1/2 inch ratchet and an extension, put it into the center of the crank pulley (through the driver's wheel well) and turn.

As for the electric compressor...if you're talking about the type that take 20 min to inflate a tire, that's probably not going to work....at all.

 

[9!'clipseDOHC]

OHHHHHHHH haha jk

thanks alot guys i also found a tech article that helped alot that i didnt see before... also it seems like the bov will leak? i mean wont it blow off at 12 psi like i have have it set to?

i planned on having someone in the car watching my boost gauge and using a really cheap electric compressor and cycling it to keep the pressure up

and is it possible to do this withot being at 30*? i dont know how to get it there with the tools i have

Yes, when the BOV opens it will leak off boost.

A little electric compressor will make this VERY difficult. If you have any leaks (which you probably do) the air will leak out faster then you can pump it in and it will be hard to hear it with the electric compressor running all the time. My advise would be to find a friend with a big tank compressor.

Its possible to do it without being at 30* but not all of the valves will be closed, allowing air to escape down the exhaust. Just rotate the crank until about 6 teeth before the two timing marks line up on the cams. The only tool you need is 1/2" drive ratchet to turn the crank.

 

[9!'clipseDOHC]

Dang it BigBeans!!! Again!

 

[eltitillo]

remember to turn the crank clockwise

 

[BigBeans]

dang it bigbeans!!! Again!

Lol, had a good laugh

 

[tips000]

Yes, when the BOV opens it will leak off boost.

A little electric compressor will make this VERY difficult. If you have any leaks (which you probably do) the air will leak out faster then you can pump it in and it will be hard to hear it with the electric compressor running all the time. My advise would be to find a friend with a big tank compressor.

Its possible to do it without being at 30* but not all of the valves will be closed, allowing air to escape down the exhaust. Just rotate the crank until about 6 teeth before the two timing marks line up on the cams. The only tool you need is 1/2" drive ratchet to turn the crank.

alright thanks... i will try it with the electric one if not ill have to find someone who has a good compressor...

 

[Calan]

Warm the engine up first if possible. It will make it harder for air to leak past the valves and rings and into the crankcase.

 

[BigBeans]

alright thanks... i will try it with the electric one if not ill have to find someone who has a good compressor...

Honestly, save yourself the time and find someone with a good compressor. That little electric isn't going to get the job done.

 

[tips000]

alright... it seems that the leak is WORSE when cold... when the car is warmed p it idles almost fine... bt when i first start it from cold it wants to stall and i have to give it gas...


also the gaskets for my throttle body are metal? i ordered one b/c i figred they were paper and the one i got was paper but whats up with the metal ons?

 

[razrman8]

If you can not get over 20 pounds of air on demand, you are going to have a lot of fun finding leaks.

Metal=Factory. If you are going to be changing them out, I highly suggest a layer of RTV on both sides of the gasket. Not a lot, just a thin layer. You'll be less likely to have it leak again. I put the new ones you speak of in, and the one that I did not RTV leaked. Thank god it was TB elbow to TB not TB to intake.

 

[BigBeans]

alright... it seems that the leak is WORSE when cold... when the car is warmed p it idles almost fine... bt when i first start it from cold it wants to stall and i have to give it gas...


also the gaskets for my throttle body are metal? i ordered one b/c i figred they were paper and the one i got was paper but whats up with the metal ons?

Those gaskets are usually some type of paper composite.

You probably need throttle body shaft seals, not that gasket (unless you know it was leaking) BTW.

 

[tips000]

Those gaskets are usually some type of paper composite.

You probably need throttle body shaft seals, not that gasket (unless you know it was leaking) BTW.

the reason i got the gasket was because i cleaned the tb... i didnt realize they were metal so i jst re sed them... my idle is low to normal so i dont think its tb to intake... i almost think it is a vaccuum line... but i wont know till i test...

 

[razrman8]

+1 On the TB shaft seal. I had a leak there for the longest time, untill I sent it (stevemonroe), who rebuilds them. Hate boost leaks, love finding them.

 

[BigBeans]

the reason i got the gasket was because i cleaned the tb... i didnt realize they were metal so i jst re sed them... my idle is low to normal so i dont think its tb to intake... i almost think it is a vaccuum line... but i wont know till i test...

Have you set your BISS?

I'm trying to find the VFAQ on it, give me a sec

 

[razrman8]

Same OP http://www.dsmtuners.com/forums/newbie-forum/396890-how-properly-adjust-biss-screw.html

 

[BigBeans]

Same OP http://www.dsmtuners.com/forums/newbie-forum/396890-how-properly-adjust-biss-screw.html

Gracias

 

[tips000]

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will this be good enough or no?

 

[razrman8]

It will get the job done. Depending on how many times you pressurize the system, it may be on alot. But will get the job done. Not everyone is fortunate enough to have huge compressors. It's all about taking what you have, and making it work.

 

[tips000]

ok also somwhere in the vfaqs i saw that yo can adjst the biss by unplugging the isc and adjsting it to 800 and then plg it back in and reset? does this work? seems mch easier than all the scan tool/ diagnostic port crap