How do I diagnose a bad turbo?

[Damkid]

Ok so my 323 smokes incredibly bad, I'm suspicious of a bad turbo but I don't know how to properly diagnose it, can someone gives me some tips as to how to go about doing this

Thanks

[turbokid]

Easiest way is to remove the intake and wiggle the compressor blades for excessive play. In and out and up and down. Sometimes if the bearings are really bad you can see wear in the intake side where the blades have contacted the compressor housing. If you see oil you're in bad shape.

[Nerd Racing]

replace with a new one, if it works then you know

[Christ]

If they're sleeve bearings, there will always be some play when it's not under load and oil pressure. The key is that the turbine shouldn't be able to touch the housing at all.

BB turbos should have no play at all.

[Christ]

Did you put the oil restriction in the feed line?

[Advancedynamix]

What turbokid explained. Except if your shaft has minimal play then then the turbo is most likely not the source of the oil. They often are blamed for the oil because they are the lowest point and oil collects there.
My b6t blows oil out the breather into the intake pipe quite rapidly under boost. It will fill the turbo with oil, so I made a baffled catch can with an auto drain. Now the car no longer smokes or consumes oil. My problem is too much ring end gap ( the rings came with too much gap when I was building this engine and I just wanted to put it together.) Worn valve guides and bad valve seals will also cause excessive crankcase pressure.

[Damkid]

I knew about checking for shaft play, that part was obvious lol just didn't know if there was more to it or not

Charlie, what you said you did maybe what I need to do, the PO of this B6T put new rings in it and I have no idea what the end gap is, I may try a catch can.... or KL swap lol

[blkfordsedan]

You could run a compression test on the motor as well. That would at least tell you how much of a factor the ring seal would be.

[DriverOne]

Rotary.

[Advancedynamix]

My engine shows 170psi across all 4 and runs awesome, but blows oil like Western Texas.

[Damkid]

I plan on doing a compression test on it tonight to try and figure out what's going on, depending on the problem, I may pull the motor and opt for something different.... Hence the reason for this thread

[turbokid]

I say a 2JZ swap and call it a day. Hey, you've done harder things.

[Damkid]

Lol I don't want to hack up the car, it's supposed to be my daily driver, plus being the rare GT model, it'd be a shame to chop it up

[Flyin4stroke]

Check the pcv. I had a b6t smoke like crazy on me and I thought it was a turbo issue but it was just a pcv valve.

[blkfordsedan]

My engine shows 170psi across all 4 and runs awesome, but blows oil like Western Texas.

Agreed, but in his case, a compression check may show an obvious issue as well. If the PO had the engine apart.....who knows what they did. In the case of my B3, it runs perfect, uses (burns) zero oil and doesn't smoke a bit out the exhaust.....but it will blow the hat off your head when you remove the oil filler cap, LOL. It will fill a 16oz catch can with oil in 100 miles. I'm guessing a broken piston.