So umm trying to do a boost leak test..

[nfernotalon]

So umm trying to do a boost leak test.. I say trying because it wont hold pressure enough to actually look for the leak! Im using a compressor too, am I not pumping enough air or is it just a huge ass leak?

It hisses very loud I think its coming from the sidemount but im by myself right now and cant look down there fast enough.. Maybe this is why my car bucks sometimes before it warms up?

Can I pressure test my sidemount by myself? If possible how?

 

[Vicious_mole]

So umm trying to do a boost leak test.. I say trying because it wont hold pressure enough to actually look for the leak! Im using a compressor too, am I not pumping enough air or is it just a huge ass leak?

It hisses very loud I think its coming from the sidemount but im by myself right now and cant look down there fast enough.. Maybe this is why my car bucks sometimes before it warms up?

Can I pressure test my sidemount by myself? If possible how?

depending on how big the boost leak tester is you can cap off one side of the sidemount and then put the boost leak tester on the other and just test it that way. it might be easier to remove the smic off the car and do it

 

[T is for TURBO]

So umm trying to do a boost leak test.. I say trying because it wont hold pressure enough to actually look for the leak! Im using a compressor too, am I not pumping enough air or is it just a huge ass leak?

It hisses very loud I think its coming from the sidemount but im by myself right now and cant look down there fast enough.. Maybe this is why my car bucks sometimes before it warms up?

Can I pressure test my sidemount by myself? If possible how?

Yes you can. You could take it off and plug one end

 

[nfernotalon]

Damn i didnt feel like taking my sidemount off right now, but looks like I will have to..

 

[T is for TURBO]

damnit you beat me too it

 

[kenamond]

Just get that corner on a jackstand and have a good look around. It might be a coupler or a big hole in the IC or endtanks. I don't know how the 1g SMIC is mounted, but it's only 2 or 3 screws on the 2g plus the couplers. Don't recall if taking the splash guard off helps get at the upper coupler or not. If you've never taken it off, take it off, straighten the fins, clean it (inside and out)...oh...and check for leaks .

It's really nice down here...must be similar up there...get your butt out in the sun, son!

 

[nfernotalon]

Yes I know its pretty warm for it being at night, its just that the damn oil return line got me down already... im a take it off and post back thanks guys

 

[nfernotalon]

Ok **update** so I quit being a lazy ass and took the sidemount off, I hooked up the boost leak tester to one end and I covered the other with my hand, I didnt hear any leaks or anything from the sidemount. When I took my hand off the pressure was still there and plenty of air came out, so I dont think its the sidemount.

What I did next was plumb the intercooler back into the car but I plumbed it outside on top of the engine instead of on the bottom corner in the stock location, I boost leak tested the whole system again and it wont hold any pressure at all, I put air in it for about 15-20 seconds and wont hold any pressure!! the piping seems fine.. any help thanks..

Youre suppose to cap off the Recirc tube and the vacuum line from the BOV right?

Also the boost gauge is suppose to give me some kind of reading too right?

 

[Vicious_mole]

couplers/clamps? any holes or anything like that? check the throttle body blade shaft seals leak all the time... but if it sounds like its by the i/c could be a coupler ? worth a shot

 

[nfernotalon]

I made sure everything was tight especially since it was right by my ear I thought I could hear something but it has to hold pressure to be able to hear something.. this sucks...

 

[Rob10_99]

How much pressure are you using for the boost leak test?
I would suggest trying to see if anything is leaking around the intake manifold/TB.

 

[srumel]

A good aid in any boost leak test is soapy water such as windex or dishwashing soap and water in a spray bottle. Spray, discriminately of course, all possible suspects like the turbo outlet gasket, piping connections, blow off valve gasket, both throttle body gaskets, injector o-rings, or the idle set screw and then try and pressurize the system and look for bubbles. Another candidate and a real pain in the butt to replace is the intake manifold gasket. This procedure has helped me immensely in the past. Good Luck!

 

[nfernotalon]

Im gonna try and pressurize from the throttle body elbow see if that gives me something.

 

[nfernotalon]

How much pressure are you using for the boost leak test?
I would suggest trying to see if anything is leaking around the intake manifold/TB.

My compressor is set at 90psi I know it takes like 10 seconds for it to pressurize so I made sure I didnt leave it too long on there, but when it didnt I left it longer on there and still nothing..

 

[nfernotalon]

Ok I pressurized from the throttle body elbow it holds pressure. I have a vacuum line disconnected that wasnt hooked to anything from the throttle body, it says A1 second one down from the rear of the throttle body, the air comes out through there when I pressurize it, if I plug it up it holds pressure, is that suppose to be hooked up to something or should I take all those vacuum lines off and cap them off at the throttle body??

 

[nfernotalon]

Anybody?

Come on kenamond we pulled through my last MBC thread

 

[tbonitz301]

I know what line your talking about. Im just not to familiar with 1g's. I know that mine gos on the firewall about 8 inches to the right of the TB. I believe its for the map sensor.

 

[nfernotalon]

Hmm.. why would it not be hooked up?

 

[tbonitz301]

Mine would always blow off when i hit boost. I just put a little cable tie around it, and its good now.

Edit: also i just thought that maybe when you put that compressed air to the system it may have seen more pressure than normal. Causing that line to pop off.

 

[kenamond]

Well, if it holds boost (ignoring the vaccuum line...which I don't know enough about (search!)) at the TB elbow, you know it has to be one of the following...starting from the compressor itself:

• Compressor housing
• compressor/j-pipe gasket
• MBC vaccuum lines or tee fitting
• MBC (it leaks back into the intake pipe which is outside of the system you're pressurizing)
• WGA
• LICP including couplers on each end
• IC (you already checked that...might clean it tonight and straighten the fins while watching CSI or Speed channel or whatever )
• UICP (first half) including couplers
• UICP/BOV gasket
• BOV (might leak back into the intake pipe via the recirc tube)
• BOV vaccuum line
• 2nd UICP and couplers

Any of the vaccuum lines can be tested by just pulling them off and capping the nipple (like the whole MBC system can be eliminated by capping the j-pipe nipple).

If you do soapy water, use plenty of soap (I use dish soap with pretty high concentration of soap).

Atleast you know it's something big between the compressor and the TB elbow. That's progress.

EDIT: And you don't want to add more than about 20psi or so when you test. Maybe set your regulator for like 90 and unplug it and just use what's in the tank. I use an 11gal portable air tank pressurized to 100psi, but it adds air slow enough that my 5-year-old daughter can sit in the driver's seat and tell me when I hit 20psi .

 

[1gDSM4g63]

I have the same situation. I tried putting air in with an air compressor with my 3" boost leak tester but I can't get any pressure in there. Will this cause erratic wideband readings and eventually the car dying down while driving or some other issue I have to look for?

 

[nfernotalon]

K then ill try tomorrow i guess

 

[kenamond]

I have the same situation. I tried putting air in with an air compressor with my 3" boost leak tester but I can't get any pressure in there. Will this cause erratic wideband readings and eventually the car dying down while driving or some other issue I have to look for?

If you can't hold any boost, that's one thing to fix...if that doesn't completely solve your problem, then go on from there.

Make sure you test on a warmed-up motor or ring blowby will leak a lot. Also, if you're unlucky, you might have tested when the intake and exhaust valves were overlapped such that boost leak test air went out the exhaust. I've never encountered this on my 2g, but 30°ATDC is the sure-fire crank placement to dodge this if you wanna bother...I'd just blip the starter and try again.

Do like nfernotalon did and test at the TB elbow to eliminate half of the intake. He was able to deduce that the major leak was before the TB elbow. Go from there.

I started dumping thoughts into a wiki on this site...take a look for potential culprits. I think I've listed the vast majority, but I'm a noob when it comes to the TB vaccuum lines and may also have missed a part, but it'll give you a pretty good list of potential leak spots:

Boost Leaks - Dsmwiki