Boost Leak lawn chair and a massive bump

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C-Rock
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Boost Leak lawn chair and a massive bump

Post by C-Rock » Thu Oct 25, 2012 11:05 pm

We have a boost leak and it's a little tough to find while driving and putting the car under load. I took a lawn chair and some duck tape and I strapped my son in law to the front of the car and took it for spin. Duck tape did not hold well and he fell off. So after some road rash and a massive bump on his head I thought I would make up something to test it and not take a chance of breaking that lawn chair.

So made up some fittings and have a 30 lbs pressure gauge and plan on hooking this up to the air intake on the turbo and then pump it up to 20 lbs. If I don't have any leaks than I should be able to hold 20 lbs of pressure with this set up going from the air intake on the turbo through the intercooler and into the throttle body and into the engine? Am I thinking right?

Thanks Cliff

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Esteban
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Re: Boost Leak lawn chair and a massive bump

Post by Esteban » Fri Oct 26, 2012 3:28 am

Duct tape? You should have used zip ties!
The system wont hold boost forever as it can seep out past the piston rings.
Pressurize the system, take a spray bottle of soapy water and start spraying the couplers, seals, gaskets, etc. You will bubbles where the air leak is.
One very common place are the throttle body shaft seals.

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Re: Boost Leak lawn chair and a massive bump

Post by timandsam » Fri Oct 26, 2012 5:08 am

I agree with esteban, the system isnt airtight. Air will leak past the rings and out the exhaust. As well as the spray bottle the esteban suggested, i used a 3' length of tubing. Hold one end to your ear and move the other end along anywhere that could possibly leak. You WILL hear it.
Mono Silver 85 XR4Ti: Ported Head| Ported Intakes|Schneider Roller Cam|Big NPR IC|3” Exhaust|Ported E6|Walbro 255|PiMP|80lb injectors|HE341|Alkycontrol|T5Z

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C-Rock
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Re: Boost Leak lawn chair and a massive bump

Post by C-Rock » Fri Oct 26, 2012 7:37 am

I agree it will bleed past the rings but it will give me some time to find the leaks and should hold the 20 lbs for a while,right?

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Mike McCreight
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Re: Boost Leak lawn chair and a massive bump

Post by Mike McCreight » Fri Oct 26, 2012 8:50 am

Here's an easier way.
Get the propane tank from your BBQ, or better, borrow one from a neighbor. Attach it using your duct tape to the turbo outlet. Crack the valve, and let sit for 1/2 hour or so, then send your son in with a spark lighter to check for leaks.
It's not a hobby, it's an obsession!

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Re: Boost Leak lawn chair and a massive bump

Post by timandsam » Fri Oct 26, 2012 4:13 pm

C-Rock wrote:I agree it will bleed past the rings but it will give me some time to find the leaks and should hold the 20 lbs for a while,right?
I really don't think so. I would hook it up to the air compressor (regulated to 20psi) and just keep it hooked up to whatever boost leak checker thing you made. It will leak alot of that air out in a hurry past the rings and such.
Mono Silver 85 XR4Ti: Ported Head| Ported Intakes|Schneider Roller Cam|Big NPR IC|3” Exhaust|Ported E6|Walbro 255|PiMP|80lb injectors|HE341|Alkycontrol|T5Z

turboplz
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Re: Boost Leak lawn chair and a massive bump

Post by turboplz » Fri Oct 26, 2012 9:05 pm

To properly test the entire intake tract for leaks, you're going to need to remove the followers from the intake valves. Assuming you have good valves and seats, this will keep the entire system pressurized until you can find the leak.

A couple common places I have found leaks are at the pcv fitting, under the lower dash there are a couple vacuum lines that have rubber couplers that like to rot over time and the most common is the throttle body shaft. If you have no obvious leaks in the system, I would thoroughly inspect those areas.
Jason

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lucky87
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Re: Boost Leak lawn chair and a massive bump

Post by lucky87 » Fri Oct 26, 2012 9:38 pm

You could try using smoke to find the leak, use all those fittings and attach it to a smoke machine. smoke comes out of the leak. I did a ghetto version with cigarrette smoke, worked well enough to find a leak near the vaccum ball thingy, (broken tube) which was easy enough to fix.

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C-Rock
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Re: Boost Leak lawn chair and a massive bump

Post by C-Rock » Sat Oct 27, 2012 12:11 am

I had made up a set up with a pressure gauge and it worked well and we have some leaks and will be getting them ironed out. I will also do this on my 89 red car. This is something I would suggest everyone do I was surprised at the leaks.

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