Cracked K04?

[BR1JZL]

Hey all, I am hoping someone can help confirm something for me.

I have a '05 Mazda 6 MPS (or Mazdaspeed6) for about 6 months, and can't seem to ever get it to perform the way that other MS6's have (car produces boost, but feels like an NA car)

I have done all kinds of diagnostics, and everything seems to check out, so I've been chasing any kind of leak and been doing smoke tests on the intake side, and I have found nothing. I have done a smoke test of the exhaust side and the smoke has come out of the side of the turbo (wastegate actuator arm side). Is this normal, or this the reason for my car performing like a stock Corolla?

I've uploaded a video for reference.

[BR1JZL]

Has anyone had a similar thing?

[Jeff23spl]

we dont see much but if exhaust side leak enough to decrease performance, you would hear an exaust leak and see black deposit where the crack is.

You can do a lot better than a smoke test by replacing inlet filter by a pipe with a nozzle to inject 15-20psi from a garage air compressor and check for leaks...

to diagnose those car you need a way to read and log obd2 parameters. the best tool is a cobb or versatuner....

btw if you have a downpipe you would usually need a tune different from the factory one...it should overboost cut a lot....

[BR1JZL]

Thanks Jeff, should've mentioned I've done boost leak tests, exhaust leak test (using shop air and soapy water), compression test, leak down test, etc and I am wanting to get a Cobb AP, but have my wedding coming up, so car funds are on hold :/.

At the moment, car isn't overboosting, its hitting 15.6PSI and settling down to 10-12PSI, so no cut.

[Jeff23spl]

humm ok, unless you datalog it to see if something wrong else where....

knock, temp or fuel could call for boost reduction at some points. your boost level isn,t far from spring pressure like if your ebcs isn,t working much to raise boost....make sure the 2 wires that connect to it, aren,t damaged and that the solenoid itself isn,t burned...

i would say to try an external manual boost control to see if you can increase it but i would wait to see datalogs unless you got something wrong to avoid zzb