Correct way to check for boost leaks + intake collector gasket question.

[Steve660]

S13 Sr20det Black top.

My car started running like crap a couple days ago and my afr went really rich at idle. I’m on map so this ment I had a vacuum leak.

I made a cap to insert into the hot pipe. What is the correct way to test the system for an sr20? I cannot cap my cold pipe as my bov just starts to leak without pressure from the vac line. Plus I want to check the engine gaskets/vac lines for leaks. What I don’t understand is if you have stopped the motor and you have both an intake and exhaust valve open won’t the pressure just go straight out the exhaust? When I did the test I could feel warm air exiting the exhaust pipe.

Either way when I hooked the cold pipe back up to the trottle I immediately found a huge leak at my intake collector (gasket between lower and upper intake). I couldn’t get the boost gauge above 3psi. This collector gasket seems like a huge pia to find. Only place I could find it was enjuku

OEM Intake Collector Gasket for Nissan SR20DET S13

Anyone know if that is a common part with an other nissan NA vehicles? Can I get this gasket somewhere in canada? If not can I use sealant or do I have to pay 3 times the amount to ship it from enjuku.

[chris240sx_3]

varun should have that gasket

[Steve660]

^ good call he has one.

I’m still interested in knowing what the right way to do this is. I have read you can pressurize the system to your boost level and a proper system should leak at 1psi/s. Does this theory work with sr’s?

[RustyS13]

@Steve660"

Anyone know if that is a common part with an other nissan NA vehicles? Can I get this gasket somewhere in canada? If not can I use sealant or do I have to pay 3 times the amount to ship it from enjuku.

no don’t use rtv just buy the gasket maybe frsport will have cheaper shipping or someone on ebay

[Steve660]

Bumping this as I still need guidence with how to properly pressure test your motor. Gasket issue resolved and fixed.

I made two end cap fittings, one with a tire stem and one with a cap to a vacuum line. I blocked the cold side of my intake with the cap/vacuum line and ran it to my bov. The cap with the stem went into the intake. This worked well, I was able to pressurize the system up to 20psi with a gas station air comp. Only issue was my bov was leaking from the cylinder, I emailed turbosmart and they said it was normal but I should clean/lube it, I’m still unsure of that answer as I expected it not to leak.

So I have no leaks in the IC piping minus the bov.

When I try to pressurize the engine I can only get up to 5psi. I can’t find any leaks anymore but I cannot get any higher than 5psi. From what I’ve read an acceptable motor should lose 1psi/second once you have it pressurized to your boost level. So why can’t I get the pressure over 5psi? Is it a flow related issue? I imagian that if an acceptable motor leaks then you need a certian cfm to get it to your boost level, obviously a turbo would produce a lot more cfm then the air pump at a gas station. Does anyone know what the required cfm is? I’ve beat the hell out of google and I can’t get a solid answer.

I’m doing all this because I have an annoying over boosting problem I can’t figure out. My wastegate isn’t openning when it use to and I keep spiking until my ecu boost cuts.

[Steve660]

I figured it out tonight, my wastegate is leaking from where the actuator arm comes out. Air was coming out quickly so that would be the reason I cant get above 5psi

[240sx_nismo]

are you running internal or external? ive had problems like this and i want to switch to external now.

[Steve660]

internal. I’ve never had that happen before but I did crack my exhaust manifold earlier this year so I’m thinking the extra heat might have lead to the failure. Wastegate was only 2 yrs old.

[Steve660]

Since this thread didn’t get many response’s for to how to correctly do a boost check, I figured I might as well update it with what I did.

This test cost me around 25 bucks in parts and loonies at the gas station. I did this because my car started to run really rich and was overboosting. I ended up finding a couple leaks that were probably always there so this was more than worth the effort and cost.

Parts required
water spray bottle with soap
2-1/2" PVC end fittings - or whatever your intake and cold pipe size is.
tire valve stem
hose barb - vacuum tube size.
A hose with a block for the idle intake tube.
An extra couple is nice but not required.

First drill a hole in the top of one of the end caps, the hole size is specificed on the tire stem package. Pull the tire stem through.

Drill another hole in the second end cap and thread in the hose barb. I put gasket sealer in the hole as well.

I attached my extra coupler and pc of vacuum tube up to the second cap.

I then took an extra pc of hose and make a block for idle air tube coming off the cold pipe.

I didn’t take many picture’s of the set up during testing but it’s striaght forward to explain. I did two test- one with just the IC piping and one with the motor.

If your like me and don’t have a compressor first drive over to gas station with an air pump .

The end cap with the tire stem gets clamped into your intake. Make sure it is after any other piping (re cir bov or crank case vacuum line)

To test the IC piping put the other end cap with the vacuum line blocking your cold pipe to the throttle body. The vacuum line then runs to your bov. You also need to block off the idle air line. Once that is all in place squirt soapy water over all the conection points. throw your loonie in the pump and hook it up and watch for bubbles. Having a second set of eye’s is almost required.

Pump it up until your IC can hold your boost pressure. Note* be carefull not to put your face in front of any of the blocks or pvc end caps you’ve made. Mine were able to hold 20psi without issue but I am not responsible if you lose an eye!

Once you have confirmed there are no leaks in the ic piping hook your cold pipe back up. Now spary all the intake gaskets, fuel injector o rings. throttle body, and vac lines. Open your oil cap then hook the air up to the intake stem again. I just run the pressure until it reachs my boost level. I found if I had any leaks it wouldn’t let me get over 5psi. I’m not sure what the cfm of a gas station pump is but it seem’s to work well. Once I had all my leaks fixed I could get it up 20psi. I didn’t bother trying to time the rate it leaked out.

I found 2 coupler leaks, 1 intake gasket leak and the root cause of my problem was a broke wastegate.