Friction sound in turbo

[djsupra7]

Cliffs- Standard fuel, intake, and clutch upgrades, with SAFC-II, at 1.2 bar on EVC-IV, tuned at a dyno. CT-26 with 57 trim and <100 miles on it. Loud pop right after letting off throttle at full boost. Metal-on-metal sound occurs immediately- no hose blow-off. Perform test run later and boost just fine. Perform test this morning with nearly warm car and sound occurs. Perform test after warming and sound disappears. Currently boosting fine.

I just completed my small project- 550cc injectors, Walbro, Aeromotive AFPR, Lexus AFM, SSQV and stock BOV run parallel, ACT Stage 3 street clutch, SAFC-II, EVC-IV (set to 1.2 bar), and upgraded CT-26 to 57 trim by PT. I have a 3 inch DP with 1.75 inch separated WG pipe (not vented to atmosphere) and 3 inch catback.

I tuned my Supra on Wednesday at a dyno and all went well. Then yesterday around 6pm, I'm driving with my brother and hit full boost no problem. When I left off acceleration, I hear a loud pop, but she doesn't die. I continue to drive her to test any abnormal conditions- I can't boost very well and an odd metal-on-metal sound occurs at about 10in Hg through boost. So I pull into a parking lot, check hoses/pipes- nothing blew off, nor anything out of the ordinary. I perform a quick low rev run in 2nd gear in the empty lot and the same sound still occurs.

Then when I'm driving my car home, still not convinced it's the turbo, I try to boost again; it's fine as if nothing happened! This was at 0.7 and 1.2 bar. Comes on right where my dyno curve shows max torque and boost!

This morning, I drove her when she wasn't completely warm and I hear the same sound: metal-on-metal. But once it warmed up, the sound went away. I haven't spun the shaft to see if there's resistance, but I'm boosting without troubles so I doubt the bearing is giving me resistance. Are there any ideas? If anyone has seen this, any input would be great.

 

[Snotcycle]

Pop= backfire?
Any more info about the "metal on metal" sound? does it get louder or change pitch with more boost (turbo spinning faster)?

from the preliminary diagnosis its possible that its spun, take off the accordion pipe and check shaft play(in-n-out, and side-to-side) and compressor blades for obvious physical damage. check the spin to see if it is catching anywhere in the rotation.

Edit: if all is well pull off the elbow and check the turbine side for damage.

 

[djsupra7]

Shaft play is fine, but oil residue is all over the turbo and around it. I'm guessing I blew an oil seal :nono:. Less than 500 miles on the turbo and this happened. I'll have to get a hold of PT to discuss it with them. This sucks...

 

[suprabad]

Oil seal for sure... but that doesn't explain the metal to metal sound. I'm thinking bearing. Don't drive it or start it until you pull the turbo, it's only going to get worse if you do. I cringed every time I read how you started/drove it after the original misshap.

 

[djsupra7]

The weird part is the sound goes away once the car warms up, or should I say the oil warms up? There's no shaft play- the bearing feels fine. My guess would be the bearing with that sound, but because it's not consistent, so I'm unsure. Oil definitely leaks out of the turbo, though. Has anyone had this happen to them this early with an upgraded turbo from Performance Techniques?

 

[randandrawson@v]

turbo bearings can do that. feel great, and be junk.
My powerstroke (big garett) made horrible noise that was intermittent as well, but boosted fine with minimal shaft play.
boosted fine till it just up and shit.

Maybe the BOV setup hiccuped and whacked your turbo real good? .

 

[boostaddict]

this actually happened to mine i didnt it sounded like mine was coming from the drivers side of the car though so i ruled out the turbo but i put an upgraded ct on mine any way and havent really driven it much since so i dont know if its still doing it

 

[djsupra7]

So I was burning oil for a while, but now it's not leaking as bad, or maybe at all, anymore. I had to add a quart of oil after a long drive- after that, I've been okay (I drove back from Portland to Seattle... 250 miles). She did just fine, however I didn't boost pretty much the whole way home. It's just baffling me. I've never seen a mechanical part behave in this way before. Does one thing, decides to stop and do something else, then stop that and make me wonder what's up. Do these seals need to set for a period of time, then they're okay? I have a large amount of oil on my bumper- I'll wash it off, drive it softly with some test boost runs for a couple days and see if I burn more oil. I'll need to clean my engine bay, too.