Trying to simulate this sound on a lift, need thoughts

[Toby_Goodmk]

I am trying to NOT replace parts like a monkey and actually find out if this is true exhaust leak. I have brought this video out before and asked for thoughts. Most come back with crossover leaks or header leaks. I have inspected headers and all are good, however with this being said the V bands are subject. I CANNOT get this sound to emit from the car on anything less than a few pounds of boost. I have tried power braking the car to simulate the noise at a stand still, but cannot get the car to hold the tires.

Why am I bringing this up again? Well I need thoughts on how I can put this thing on a lift, and have someone operating the car. If I cannot get boost pressure, how in the world can I find if I have true exhaust leaks?

On Monday I will be ordering a new set of headers if I cannot find any sign of noise anywhere else, and I would hate to think if I replaced the headers.....and the sound still be there from something else that I did not diagnose properly.

I am trying to eliminate the possibility of a head gasket leaK??????

 

[No disintegrations]

Find a way to stuff rags in the tailpipes. Maybe hold them in place with a carefully place visegrip. That should build enough pressure in the exhaust to accentuate any leaks. No boost needed, I would think with this test.

 

[dynoman]

Sounds like an intake leak to me . Only under boost ( intake pressure) , you won't hear a vacuum leak . I would try spraying carb cleaner around the intake and listen for engine stumble , or pressurize the intake tract & plug exhaust and snoop it . ( soapy water ) When I blew a head gasket straight to the outside, it sounded a big header leak .

 

[Toby_Goodmk]

Sounds like an intake leak to me . Only under boost ( intake pressure) , you won't hear a vacuum leak . I would try spraying carb cleaner around the intake , or pressurize the intake tract & plug exhaust and snoop it . ( soapy water ) When I blew a head gasket straight to the outside, it sounded a big header leak .

I was thinking this as well. Plug exhaust as in shop rag thing to tail pipes or take the covers off and loosen rockers?

 

[Pronto]

If you pull the rockers and let the valves seal, you can pressure test the intake and then the exhaust. I made an intake tester with a pvc cap and tire valve.

 

[dynoman]

I would plug the whole system and check exhaust too . I don't know if rags would seal it up good enough, just don't put too much pressure in it . No more than the boost your running .

 

[dynoman]

Or what Pronto said .

 

[Toby_Goodmk]

If you pull the rockers and let the valves seal, you can pressure test the intake and then the exhaust. I made an intake tester with a pvc cap and tire valve.

Intake plug test seems pretty self explanatory with a PVC cap. Did you use a 2-3/4" plug into your up pipe to throttle body? How about a type of a cap for the exhaust? Go from the tail pipe?

 

[blackazz]

This is how I do my pressure test.
One goes on throttle body other one plugs down pipe.never give it more air then the max boost

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[Toby_Goodmk]

This is how I do my pressure test.
One goes on throttle body other one plugs down pipe.never give it more air then the max boost

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The plug used for the downpipe, what exactly is that? It does not look like a fabbed piece

 

[dynoman]

That is called an inflatable pipe plug . I see that Home Depot has them . They come in different diameters .
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=inflatable pipe plug

 

[Toby_Goodmk]

GREAT ideas

 

[blackazz]

http://turboboostleaktesters.com/evo-8-9-fp-black-red-green-white-2-5-64mm/

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[blackazz]

When I bought mine they where 15 bucks.

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[Toby_Goodmk]

hell I think I may be able to make one to get the test done sooner. So one test you are leaving the rockers down, the other test you are taking the rockers loose??

 

[blackazz]

http://www.evolutionm.net/forums/evo-how-tos-installations/339529-how-boost-leak-tester-5-02-a.html

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[Pronto]

This is how I do my pressure test.
One goes on throttle body other one plugs down pipe.never give it more air then the max boost

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The one I made is similar. I used a thumbwheel regulator and guage. You get the idea. You'll only need about 10 lbs of pressure to show the leaks.

 

[TurboBuRick]

I like to use a shop vac with the hose on the exhaust side of the vacuum. Clamp the hose to the maf pipe and turn on the vacuum. Do the same with on the exhaust. If you have dual's just cap the other pipe. The vacuum moves enough air you do not have to mess around with the rockers. Use soapy water in a spray bottle on suspected areas.

 

[TurboSmart]

For exhaust system..
Disconnected the turbo from the downpipe.
Sealed tailpipes with a plastic bag and zip tie.
With a water hose, start adding water until the system is filled with water.
Look under the car for leaks.

As for header and crossover leaks,
Header... used the rubber hose trick and check for noises.
Or
Seal one tailpipe with a wet sponge and bag.
Start car
Look for signs of water condensation drips or sprays.

One detail... there are times that faulty vbands leak when cold and seal up when hot.

 

[Toby_Goodmk]

for $10$ I made my own intake pressure tester and bought a test plug ball on ebay for 10$. So I have $20 in a complete test setup for this weekend. Last weekend was able to place the car on the lift and listen for exhaust leaks, and found none. Actually we did not find anything with trying to load the exhaust so I am going to go this route. Couldn't get the rear brakes to hold boost either. Adjusted the rear brakes....nadda.. My Hydroboost is leaking and is tired, so it will be replaced with a new hydratech unit. Keep plugging away till I find something.