funky boost leak test results

[TurboStutr]

I've been doing a boost leak test on my car and can't seem to figure out what's going on. First it was leaking from the little breather filter that I have on the valve cover. Then I plugged that up and then it was leaking from the oil dipstick. I recently replaced the PVC valve with another OEM one from the dealer so I don't think that is the problem. And I just got a Greddy oil catch can to replace the breather, because it's getting clogged up with oil(but I haven't installed it yet). Any ideas on what could be going on and some possible fixes? I know I'm getting excessive crankcase pressure, I just don't know how.

 

[FORMONTOYA]

Where are you testing from?
If it is the turbo inlet, it could be leaking past the seals which is normal if the car is cold. Switch the test to the lower ic pipe and see what happens.

Jim

 

[TurboStutr]

Where are you testing from?
If it is the turbo inlet, it could be leaking past the seals which is normal if the car is cold. Switch the test to the lower ic pipe and see what happens.

Jim

ahhh i did not know this...yeah i was doing it from the turbo inlet. i'm gonna get right on that and see what happens, thanks.

 

[TurboStutr]

i just tried it from the lower intercooler pipe with the same result...i pull off out the oil dipstick and get a poof of air that still comes out, and it still wont hold pressure

 

[majik2k5]

If you have excessive crank case pressure, it could be bad rings. Or in my case, and bad headgasket.

 

[GSX93DSM]

I know on mine. I did a boost leak test and i could hear it coming from the throttlr body area.
But what was weird th egauge would only go to 10psi, all the air i was putting in was coming out as fast as i put it in. Finally after a lot of fustration i sprayed the tb dowm with soap and water i found leaks from everywhere possible on it. What didn't help was my idle was messed up from the aicv. Which my friend had one and cahnged it. so i know i know it feels to to be in your position?

Never quit to you Figure it Out!

 

[PieEyedPiper]

I'm not positive on this but I BELIEVE Oldman has intructed me to NOT, under any circumstances, block that breather port on the valve cover.

Just a fyi.

 

[oldman]

I'm not positive on this but I BELIEVE Oldman has intructed me to NOT, under any circumstances, block that breather port on the valve cover.

Haha, that is right. The problem is intake pressure leaking into the crankcase, by plugging off the "BREATHER", you're forcing pressure to find other ways out. Open the oil cap every time you pressure test to avoid crankcase pressure build up.

That said, couple of questions and suggestions for the thread starter.

1. Is the car smoking? If so, when?

2. Did you discover oil in the licp?

3. How much pressure was the intake tract able to hold when testing from the licp?

4. Repeat test with the pcv hose removed from the intake manifold with the fitting capped, listen for leaks under the oil cap as well as compare holding pressure to prior test.

5. Perform a dry and wet compression test.

 

[TurboStutr]

I'm not positive on this but I BELIEVE Oldman has intructed me to NOT, under any circumstances, block that breather port on the valve cover.

Just a fyi.

i just plugged that up during the boost leak test, i normally have the filter on it when i'm driving it around...at that point i was just trying to see what was leaking worse.

i started out with an intake manifold gasket leak, then replaced that so its not leaking anymore, but now i have all these little miscellaneous problems that i just cant seem to find a solution to.

 

[TurboStutr]

Haha, that is right. The problem is intake pressure leaking into the crankcase, by plugging off the "BREATHER", you're forcing pressure to find other ways out. Open the oil cap every time you pressure test to avoid crankcase pressure build up.

That said, couple of questions and suggestions for the thread starter.

1. Is the car smoking? If so, when?

2. Did you discover oil in the licp?

3. How much pressure was the intake tract able to hold when testing from the licp?

4. Repeat test with the pcv hose removed from the intake manifold with the fitting capped, listen for leaks under the oil cap as well as compare holding pressure to prior test.

5. Perform a dry and wet compression test.

1. i didnt notice the car smoking till just this evening, after it sat idling for a few minutes i revved it and BLAH, out came that wonderful cloud fo smoke. so i think my new PCV valve is shot once again. its the same problem i had when i replaced the PCV valve with an OEM piece about a month ago.

2. nope, none at all.

3. i just had a bike pump on it, but as fast as i could pump it in, it was coming right back out. i can get it hooked up to a compressor tomorrow.

4. i'll definitely be doing that tomorrow as soon as i get out of work. whats the best thing to cap that fitting with to keep it from popping out easily?

5. i can get one of my friends to help me out with that since i dont have those tools, but i'll be putting up results as soon as its done.

 

[oldman]

1. i didnt notice the car smoking till just this evening, after it sat idling for a few minutes i revved it and BLAH, out came that wonderful cloud fo smoke. so i think my new PCV valve is shot once again. its the same problem i had when i replaced the PCV valve with an OEM piece about a month ago.

PCV, valves seals or rings, most likely valve seals.

4. i'll definitely be doing that tomorrow as soon as i get out of work. whats the best thing to cap that fitting with to keep it from popping out easily?

A 1/4" fitting cap with zip-tie, you can pick them up at autozone or the likes.

5. i can get one of my friends to help me out with that since i dont have those tools, but i'll be putting up results as soon as its done.

Make sure you guys follow the directions as written, half a cap full for the wet test.

 

[TurboStutr]

PCV, valves seals or rings, most likely valve seals.


A 1/4" fitting cap with zip-tie, you can pick them up at autozone or the likes.


Make sure you guys follow the directions as written, half a cap full for the wet test.

will do, i printed out the directions a few minutes ago...and thanks for the help, i'll put up results as soon as i can

 

[laserspeeddemon]

I was going to say valve seals. I got some ideas, maybe oldman (congrats on the mod status, by the way) can confirm these, this what I did to isolate the leak.

My wifes eclipse was leaking boost, on a boost leak test, I found all the external leaks. (IC piping, IC, etc.). My last few concerns was the PCV, valve seals, TB seals, and turbo compressor seal (not likely).

First, I did the test from the Lower IC (as I was sure the compressor housing seal was good) - stilll was leaking boost

next while I had the IC tract pressurized I opened the throttle, there was no change in pitch - that eliminated the TB seals,

next I removed the PCV (while still connected to the manifold) - found a leak,

I also covered the pcv outlet with my finger and heard a very very slight, bearly audible hiss. So my valve seals were bad too.

Anyway, hope this helps.

 

[steve]

One of the hard ones to find is when the EGR valve leaks. Not the EGR gasket but the value. The gasket will leak to the outside but the valve leaks from the intake manifold through the head to the exhaust manifold all internal.

Steve

 

[FORMONTOYA]

One of the hard ones to find is when the EGR valve leaks. Not the EGR gasket but the value. The gasket will leak to the outside but the valve leaks from the intake manifold through the head to the exhaust manifold all internal.

Steve

I never thought about that spot. I will have to keep that in mind in the future.

Jim

 

[oldman]

I was going to say valve seals. I got some ideas, maybe oldman (congrats on the mod status, by the way) can confirm these, this what I did to isolate the leak.

Haha, I'm not sure if it's a promotion but thanks anyway. Not bad on the troubleshooting, looks like you have mastered the art of boost leak testing.

I never thought about that spot. I will have to keep that in mind in the future.

Put your ear up against the tailpipe.

 

[FORMONTOYA]

I knew I was supposed to listen at the tailpipe, but did not grasped the concept of what would be leaking if I heard a sound from there. Mine must be good then as I did not hear anything. At least not yet.

Thanks for the clairafication.

Jim

 

[oldman]

I knew I was supposed to listen at the tailpipe, but did not grasped the concept of what would be leaking if I heard a sound from there. Mine must be good then as I did not hear anything. At least not yet.

Thanks for the clairafication.

Jim, hissing from the tailpipe can mean one of two things.

1. A stuck open EGR valve like uncle steve posted.

2. Valve overlap, both intake and exhaust valves open in between the end of exhaust stroke and beginning of intake stroke.

 

[FORMONTOYA]

2. Valve overlap, both intake and exhaust valves open in between the end of exhaust stroke and beginning of intake stroke.

From my searching in the past I was under the impression that before a leak test I should rotate the crank CW to get ~30 deg off TDC to avoid this. Of course with air tools and a bladder jack, it is real easy to get the car up on stands.

Jim

 

[oldman]

From my searching in the past I was under the impression that before a leak test I should rotate the crank CW to get ~30 deg off TDC to avoid this. Of course with air tools and a bladder jack, it is real easy to get the car up on stands.

Jim

You should but most people don't, obviously, you have done your homework well.

 

[Black94DSM]

How do i know where 30 degrees off TDC is ?

 

[FORMONTOYA]

How do i know where 30 degrees off TDC is ?

As you are rotating the crank by hand CW, NEVER TURN THE CRANK CCW, the timing "notch" on the crank pully will be roughly at 12:00 o'clock. It does not have to be exactly a measured 30 deg, but roughly 30 deg.

Jim

 

[laserspeeddemon]

Just to clarify

CW= Clockwise
CCW= Counter-Clockwise

At first, I thought he was talking about Crankwalk.

 

[FORMONTOYA]

Just to clarify

CW= Clockwise
CCW= Counter-Clockwise

At first, I thought he was talking about Crankwalk.

You are correct. Sorry for the confusion, I'm just an assuming kind of guy. I guess that is why a lot of people think I'm an a**.

Jim

 

[Black94DSM]

As you are rotating the crank by hand CW, NEVER TURN THE CRANK CCW, the timing "notch" on the crank pully will be roughly at 12:00 o'clock. It does not have to be exactly a measured 30 deg, but roughly 30 deg.

Jim

Thanks for your help. I didnt think it was that easy.