Help with boost leak test?

[Frickadella]

Test not working as I expected.

I removed intake hose to turbo inlet and put on blt coupler. I removed oil cap. Put on bicycle pump - it's all I have atm. There is pressure right away, 20 psi, but only as long as I'm pushing the pump. As soon as pump is down, pressure drops to zero. I could only hear air coming out of oil filler cap.

I expected it to take a bit to fill the system and pressurize, so I loosened the lower ic from the turbo outlet and expected to hear a hiss, but no. I removed it and expected to feel air as I pumped, but no. What the hell is going on? Am I missing something?

Thanks in advance.

 

[Calan]

1. Make sure the motor is at TDC

2. Make sure the motor is warm.

3. Find something other than a bicycle pump. It won't flow enough air at enough pressure to do much of anything.

 

[faudin]

the leaks are hard to find. and yes get a compressor and set it for 20 psi, and a spray bottle of soap and water is your friend on this one, spray everything down and watch for bubbles if you dont see any spray each area at least 2 or 3 times you dont always hear slow leaks so best of luck to you.

 

[Frickadella]

Thanks for the replies.

I'll be happy to do all that if I can rent a compressor, but the problem seems to be I'm pumping air into the inlet side and none is coming out the outlet. What does TDC or warming the engine have to do with that? I kind of expected the air to flow right through the compressor housing with zero restriction. It seems more like I'm forcing air past the turbo shaft and into the oil system?

Yes, I R turbo-newb.

 

[darthvadar tsi]

Like said in the above comments get an air compressor set it to 5 psi to start off with. and just hold on the tester. keep the air constant while feeling around for air coming out and spraying with soapy water. This wont hurt anything but you can remove the oil cap and listen for leaks there. The easiest place to start for me was the throttle body. Check the gaskets and The back of it and the intake manifold. Good luck man.

 

[miguelmcv]

Definitely you need a compressor, with the bike pump, it will pump 1psi on each pump which a leak will loose more then 2 psi, so even with soppy water you wouldn't see the leak.

 

[Artago]

Thanks for the replies.

I'll be happy to do all that if I can rent a compressor, but the problem seems to be I'm pumping air into the inlet side and none is coming out the outlet. What does TDC or warming the engine have to do with that? I kind of expected the air to flow right through the compressor housing with zero restriction. It seems more like I'm forcing air past the turbo shaft and into the oil system?

Yes, I R turbo-newb.

TDC ensures all the valves are closed.

Warm engine ensures all the seals and piston rings have expanded and aren't leaking that way.

Oh and you NEED a compressor for this. Bike pump wont do, I've tried.