Boost leak tester problem

[odormat000]

While checking boost leak do you need to have anything else blocked off or have your engine at TDC? I would think that if i pressurized my pipes it would just go into an intake valve and leak out an exhaust valve or something of that means. Also I would think it would leak out the recirculating breather tube on my valve cover. Any advice on what to do to keep it under pressure?

 

[turbosax2]

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

I have never turned my motor to 30* ATDC while doing a boost leak test and haven't had a problem performing the test. The only thing I block off is the mbc. Another option is to leave your oil cap off during the test so you don't accidentally over-pressurize the crankcasae.

 

[redline2k6]

usually with the throttlebody closed you can check all your intercooler pipes without a problem and even with the tb cracked open ive never had a problem not finding the leak

 

[tunethis]

I had to "blip" the starter a couple times because it took a long time to show boost on my gauge. Once I did that, the gauge showed boost instantly as I pumped in air. As long as your gauge shows boost instantly, you know the valves are in the right spot.

 

[odormat000]

I did the test and should there be any air leaking where the throttle return spring shaft is? if not how do i fix something like that?

 

[kenamond]

I did the test and should there be any air leaking where the throttle return spring shaft is? if not how do i fix something like that?

Those would be the throttle body shaft seals. Those seals are a common boost leak. The VFAQ has an article that details how to replace them. It's a bit harder than fixing some of the other boost leaks.

If air is coming out your VC breather line, it can be one of three things: leaking PCV valve, bad compression (worn rings) or intake valve stem seals. Make sure you test on a fully-warmed motor; it makes a big difference with blowby past the cold rings. If your PCV valve is bad (pull it out of the VC and test; nothing should leak out the tip), get an OEM one, not an Autozone/Carquest/etc. one, as they don't hold boost even when brand new.

Make sure you find all leaks around the TB before you pull it to fix the shaft seals or you might get to pull the TB again to fix another leak. Find as many leaks as possible and then go to town.