Test your BMW twin turbo the easy way & Get your boost back!  

This Boost Leak Tester kit mounts inside both of the flexible intake hoses that lead to your turbo's compressor inlet flanges.  You will need to remove the air box (or your aftermarket air filters) to expose the 2 intake pipes. Install the testers in each pipe and pressurize the system using the tire schrader with your tire inflation tool.  The kit comes with the necessary caps to block the diverter valve return flanges on the intake pipes, also a cap to block the breather line at the back of the valve cover.  Once the kit is installed, use compressed air to charge the system and you will see that both gauges read the compressor pressure you are filling with.  You'll be able to test the turbo to the motor checking all leak points in between, including intercooler, clamped connections, intake manifold, divertor valves and the many random potential leak points.

This is an important tool that every turbo car owner needs in their arsenal of tools.  It is going to keep the turbo healthy by eliminating leaks in the boost path and not allowing it to over speed compensating for a boost leak.   It is a must if you are tuned and or going to get a custom tune, or any time you are replacing any components in the intake tract such as charge hoses, intercooler, manifold, vacuum lines, injectors…etc.  Also a must if you are going to the track and want the peace of mind that everything is tight and capable of handling sustained boost without blowing any hoses off

Importance of the tester's boost Gauge?

Not having a gauge readout on a boost leak test is similar to filling air in your car's tire without a gauge.  You just don't know how much air is in the system!   

It is very wise to know how much pressure is actually going into the charge system to prevent damage to your engine and to yourself - Example if the compressor is unregulated (using high pressure shop air at 90 PSI) there is a risk that the charge pipes will be over-pressurized and something will give - the boost leak tester could blow off or any component of the engine could.   

The gauge on the boost leak tester allows the user to:

1. apply a safe amount of pressure to prevent injury or damage to the charge pipes or engine
2. read how fast the system holds and bleeds air after removing the air source
3. give a good comparison of compressor outlet air Vs. boost test air while pressurizing.  The smaller the difference the lesser the air loss in the system

Design Features:

• Durable Plastic End Caps with 1/8" NPT threaded gauge port & fitting port
• Upgraded Boost Gauges with 15 PSI / 1 Bar Readout.  Stainless Steel housing, very durable.
• Universal Tire Schrader Valve (can be removed and tapped for 1/4" NPT thread fitting if desired)
• (2) Stainless Steel T-Bolt Clamps with Nylon lock-nut
• (3) Rubber Caps for Diverter Valve Return and Valve Cover Breather

Applications:

• 2006–2010 E90/E91/E92/E93 335i with N54 TWIN TURBO engine.
• 2007–2010 E60/E61 535i with N54 TWIN TURBO engine
• 2011–2013 E92/E93 335is with N54 TWIN TURBO engine
• 2011 E82 1 Series M Coupe with N54 TWIN TURBO engine

Important Notes while testing: Testing at the intake pipe, you may hear noise coming from the turbo inlet o-ring (at ~12 psi test pressure) that seals the intake pipe to the turbo inlet from debris.  This is not a boost leak, these are not meant to see boost and not intended to be perfectly sealed, however hearing this hissing may be mis-diagnosed as a leak since it is pre-turbo not post-turbo.  In this case reduce the pressure.  If no obvious leaks are heard in any other location, the test is complete and there are no significant leaks.  If the inlet pushes out from the test pressure, it needs to be pushed back in and held in place with a wedge.  This indicates the inlet seal may be worn out.

Remove the intake air box or aftermarket intake filters to expose the inlets.   This is where the tester end caps will slide in.   Disconnect the Diverter valve return at the intake pipes and cap off the intake pipe with provided (2) rubber caps.   The 3rd (smaller) cap is for the PCV block on the intake pipe.   Follow the rear of the valve cover, there will be a hose that connects the valve cover to the rear intake pipe.   Disconnect at the intake pipe and cap off the intake pipe with 3rd rubber cap.  

While testing, remove the oil cap to vent any possible build up of air pressure