Boost Leak help

[Street_Killer]

Hi, I was wondering if there is anything for cracks that can get in there and seal up. Ive had a leak in the same spot of my throttle ody no matter what spot, whether I use the gaskets or silicone. Its so annoying. Its a bad leak to, I cant even build pressure during a test.

Also, where are some other possible leak places, the average person like me would not know to look?

One more question. When doing the test, I noticed a girgling kind of sound like when pouring oil in your car, but a lot slower. Kind of like Gurgle.........Gurgle..........Gurgle. Almost like a big water bubble popping.

 

[EagleTalonTim]

Take a look at this link : http://www.vfaq.com/mods/ICtester.html

the bubbling in the motor is more than likely the turbo leaking air around it's seals and pushing back into the oil pan. Mine does the same thing when I run a boost leak test. not very noticeable anymore. Be sure the engine is warm when you do the test. If you are using a bike pump, stop......use an air compressor and turn it down to 20psi.

 

[schoffs4]

boost leak with the rad cap off check for head gasket problems

 

[Street_Killer]

boost leak with the rad cap off check for head gasket problems

Are you saying the gurgling could be the head gasket, or just a suggestion?

 

[EagleTalonTim]

I think that was just a suggestion. If the sound is coming from the oil pan, it is more than likely what I stated above.

 

[Street_Killer]

Ok, thanks for the help. Im using a compressor to by the way.


So does anyone know of some good sealant? Something that could get into cracks.

 

[GVR4592]

If a factory gasket doesn't seal it, there's another problem. Have you replaced the throttle body shaft seals?

 

[Street_Killer]

Ya, its a bran new tb. I can feel see where the air is coming out. Im thinking maybe the metal is a little wapred in a spot.

 

[oldman]

1. Disable your mbc.

2. Turn your motor to 30* ATDC to avoid valve overlap.

3. Start your test at the TB elbow and focus on area behind the TB first.

4. Spray soapy water at TB gasket, BISS, TB shaft on both sides, IM gasket, injector insulators, brake booster, afpr and all vacuum lines/connections.

5. Open your oil cap and listen for leaks. (PCV, valve seals/guide, rings)

5. Listen to your tailpipe for leaks. (EGR, valve overlap, jumped timing, bent/unseated valves)

6. Once all leaks are fixed, move the tester back to the turbo inlet.

7. Spray down the compressor cover (known leak), BOV return/flange (DO NOT TAP YOUR BOV LINE FOR YOUR MBC!!!), IC end tank/fins and all connections. Re- test.

8. Note that you will leak air into the crankcase through the turbo seal but do not panic, this is normal during a static pressure test as long as there are no shaft play.

The desired test result from the begining of the LICP (bypassing turbo) is around 20psi (on boost gauge) with the compressor set at 30psi, while taking no less than 30 seconds to bleed down to 0.

As a reference, my last test on my 500 mile new engine, I was able to pressurize the system to 25psi, bled down to about 16psi (my 1G bov) in about 30seconds, then took about 3 mins to 6psi and just kinda lingered there for a while. It's not easy to do but the point is it's possible. My next goal is 30psi After motor break in and Dodge modding my BOV. A boost leak test is one of most pita but important regular maintenace task, the key is patience and endurance, have fun.

boost leak with the rad cap off check for head gasket problems

You're thinking of leakdown, boost leak test will only pressurize one combustion chamber at a time. Lastly, please make sure to use proper caps and punctuation in tech posts.

 

[Street_Killer]

Thanks for the info. Now I really need someone to answer about sealant that could seep into a small crack and possible seal it up. Im 99.9% positive the probelm with my leak is the metal being dented in on the throttle body, so it cant seal up properly even with a gasket.

I was thinking maybe some type of glue?

 

[oldman]

Thanks for the info. Now I really need someone to answer about sealant that could seep into a small crack and possible seal it up. Im 99.9% positive the probelm with my leak is the metal being dented in on the throttle body, so it cant seal up properly even with a gasket.

I was thinking maybe some type of glue?

You shouldn't make that assumption until you repeat the test with soapy water, you certainly don't want to seal it and having to take it off again because you discover more leaks, for example TB shaft seals. Once you have confirm the leak is in fact cause by warped flange, you can apply RTV on both sides of the stock gasket. If that won't seal it, I would suggest you re-surface the flange/flanges.