Loud Metal Bang
 

Having a LOUD!!! Metal bang come from my transmission area, like someone hitting a hammer on a metal box.
It is not continuous or rhythmic.
It happens while driving and stationary.
It does NOT happen at all when the clutch is disengaged (clutch pedal all the way to the floor)

NO problems shifting, or driving.

Car's at DB's they are going to check into it on monday/tuesday.

Any ideas what i'm into here?

Re: Loud Metal Bang
 

Is there anything that you do to make it happen. such as engaging the clutch in neutral, or in gear. there has to be some way to trigger it to happen. Sheared off some teeth maybe on the gearset or something break internally to the transmission floating around in there? Drain the tranny fluid to see if there is any metal floating around.

Re: Loud Metal Bang
 

could it possibly be a spring in the clutch came out, or some other clutch destruction

Re: Loud Metal Bang
 

loose flywheel bolts is my guess

Re: Loud Metal Bang
 

I know what sheered off teeth sound like, I had the whole rocks in a coffee can before i sent this bastard off to TRE. I've been searching other forums, and I don't think it's a spring because it was driving fine. I really hope Swanny is on to something and that it's just loose flywheel bolts. Idk why i'm still running a stock flywheel but i've heard that the bolts like to come loose.

Re: Loud Metal Bang
 

They drained the fluid, no metal in it and none on the magnetic plug.

Re: Loud Metal Bang
 

Soooo confused. Drained the oil, clean.
car would NOT boost at all after picking it up, but it also would NOT make the loud metal bang we heard several times on the dyno.

Checked all the vacuum lines, checked for leaks ect none. pulled the turbo. Will not spin at all if there is pressure on it. Was feeding the turbo from the oil filter housing with a restrictor. Was not pushing oil at all.

put my 20g back on using the same lines i had the scm6152 hooked up with, again from the oil filter housing. runs fine boosts hard no loud metal bang.

only question? why/how could the bang have been from the turbo? maybe unsticking its self?

Re: Loud Metal Bang
 

Unsticking, or becoming stuck. If it was spinning at speed (tens of thousands of RPMs) and suddenly stopped that would make a hell of a noise.

Re: Loud Metal Bang
 

makes sense. Mailing the turbo to PTE tomorrow to find out why it failed and get a new center section. Idk why it failed though every thing was hooked up perfectly, it was stored sealed, and we unplugged my TPS before starting to the car to charge it with oil.

Re: Loud Metal Bang
 

unplugged CAS not TPS

Re: Loud Metal Bang
 

lol you are correct sorry i was picturing the cas in my head and typed tps.

Re: Loud Metal Bang
 

Shitty. A turbo is easier to replace than a transmission you just stuck money into and fucked around with all winter though!

Re: Loud Metal Bang
 

Speaks from experience!

But, yeah turbo would be better to replace. At least you can still boost on ur 20G.