Yes, another boost leak test thread!

I just got back from getting a boost leak test done. Pretty concerned with the outcome.

We took off the mas/filter and secured the tester. Started up the compressor and began the test. We heard a small leak with the throttle body seals. Very common thing with evos.

One strange thing is, my boost gauge would hold no more than 8psi MAXIUM. We were using a 200 gallon air compressor FYI.

The thing that most concerns me, is you could hear the compressed air flowing out the exhaust. If you'd put your hand down by the muffler tip, you could slightly feel the air coming out.

So, the questions begin:

Anyone experienced this? We're assuming it's possibly bent valves?

We're doing a compression test tomorrow to see what we come up with, but any suggestions/comments are welcome!

Thanks!

 

Lots of us are having boost leak issues.hehe ( a few threads on here just form today).
I have one as well. When your testing at 8 psi, did you hear a noise, like something manually opening up when it started to leak? Reason I ask is I am in a similar situation as you, but I have that weird noise.

 

No sir.

You could instantly hear the TB seal leak, which I was 99% sure it was going to anyway after researching on here.

The main thing, is hearing the air come straight out my exhaust...Did you have the same thing happen with your exhaust?

 

I couldnt isolate the noise, but that could have been. tomorrow I will check if its coming out the exhaust at all.

 

Trust me, you'd know if you heard it. It almost sounds like when you fire up a propane tank...

 

hmm. maybe that groaning noise was that then.

 

I've noticed that if you set the motor to TDC for the test there's a little "sweet" spot that won't hold pressure and it will blow it straight out of the exhaust. If you were set to TDC, try rotating the crank a little until you hold pressure.

 

when my TB seal was leaking it wouldnt hold more then 10psi! do you have a MBC??