What is this? It's making a lot of noise

[zbph10]

I'm a new turbo owner and this thing is making a heck of a racket while the cars ignition is either in the ACC position or if the car is running. It's somewhat intermittent. Car is a 91 turbo. It runs and drives fine, just noisy.



What needs to be done?

Thanks
Brian

[burgermeister]

I have NEVER seen a Turbo or owned one, but I'm curious. Perhaps something involved in oiling said turbo's bearing?

[zbph10]

BTW It's on the drivers side exhaust piping.

[Oh Haha]

The Turbo forum would be a better place for this question.

You should post over there as well.


That is the wastgate, BTW.
Can you describe the noise? Are you getting full boost?

[RarlyL8]

That is the waste gate and catalytic converter / heat shield form a C2T.

I don't know why it would be making a noise unless the heat shield is vibrating against something.

[richde]

Originally Posted by Oh Haha

The Turbo forum would be a better place for this question.

You should post over there as well.


That is the wastgate, BTW.
Can you describe the noise? Are you getting full boost?

What controls wastegate actuation? Could it be getting erratic inputs or maybe be unable to function properly, the noise being the wastegate attempting to position itself.

[spuggy]

Originally Posted by richde

What controls wastegate actuation?

Positive pressure in the intake manifold, aka "boost". The control input is connected above a big diaphragm connected to a big valve with a big spring.

When there is sufficient pressure (factory setting is .7 or .8 bar) above the diaphragm to overcome spring pressure and open the valve, it dumps exhaust gas before it drives the hot side of the turbo in order to regulate the intake manifold pressure.

You cannot get this without load on the motor - e.g. revving the car to any RPM you like at a standstill is unlikely to build significant boost.

Could it be getting erratic inputs or maybe be unable to function properly, the noise being the wastegate attempting to position itself.

What sort of noise? Rarly's "heat shield rattling" sounds like the best explanation.

If it does it with the ignition to ACC and the car not running, are you sure it's coming from there? The fuel pumps make a racket, but yours shouldn't run until the plate on the air metering moves off the stop...

[Britwrench]

The heater blower motor is directly above the wastegate, sure it's not that?

[bolt]

+1 what Britrench said....if the car engine is NOT running but key is in ACC position, and you hear the noise- try turning off your heat and blower/fan to see what happens.

otherwise +1 what spuggy and rarly said.

good luck.

[zbph10]

It's not doing it today so next time it makes the noise I'll try it.
Thanks for the ideas!!

[zbph10]

I started removing fuses until the noise went away and it was the drivers side blower motor. I pulled it out and it was completely shot.

Thanks for the help
Brian