For a while I had a failed WG actuator, that would cause boost creep like no other.

I replaced it with a working actuator, but now it makes a clicking noise at idle, and low RPM. I applied air pressure to the wastegate actuator, to verify the problem.

The clicking sound occurs when the wastegate is closed, with the engine under vacuum.

When the absolute pressure reaches atmospheric (0 psi), the clicking noise stops.

Has anyone ever had this problem? I want to replace it if it is a geniuine problem, but the actuator is currently working great, and I have no boost creep in any gear. It's only that clicking noise that bothers me.

 

maybe some joints in the assembly are loose so it rattles/resonates at certain pressures, kind of like holding a piece of paper to a flat surface and blowing across it, you can make quite a bit of noise with it. that may not be it, but I'm not sure what it would be otherwise.

 

is it the actual wg flapper door rattling? if the airflow through the wg at idle is greater than that of the tension on the door it'll rattle.

 

^^^ I'd say that could be considered one way of being loose. Can the waste gate tension or position be manually adjusted? I haven't taken my turbo out yet to learn these things...

 

See, that's what i'm thinking, but the sound never happened on my previous actuator.

As for your second statment:

During idle I don't have pressure, only vacuum. I realize there must be some airflow, but wouldn't having a vacuum "suck" the wg flapper shut? The actuator works by pressure right?

I don't know of a way to adjust the tension on the rod besides bending the actuator mounting tab; the clicking sound may be because my engine is currently not tuned, so it runs rough at idle causing vibrations.

So far I have two suspects: the actuator, or the flapper.

 

well i would think that either resonating heat waves might be pushing the flapper open slightly or it could just be vibrating from the engine transfering to the flapper. i had this problem with my aftermarket adjustable actuator and arm. stock arm has no adjustment but most likely you just need a little more tension which could be achieved by bending the flapper arm slightly or maybe even wedging in a piece of wire around one of end the actuator arm to add an extra mm of tension. that might be enough to stop the vibration. i would just get the car up on stands and let it idle and inspect the actuator arm by putting tension on it to see if the vibration stops.

 

I'm having trouble picturing how that is done. I'll try bending the actuator arm to see if I can remove some 'slack' from the travel. Thanks for all the help, by the way.

 

with the car running pull the actuator towards the front of the car (towards the actuator). if there is a little play you can do what i described above my wrapping a piece of thin wire around the end of the actuator arm (the hole the nub on the flapper arm attaches to). kinda hard to describe but

((O))======

the parentheses being the eyelet on the end of the actuator arm that slips over the nub where the c clip locks it in. before if there is a slight bit a play you can wrap a bit of wire around the eyelet making the opening smaller and thus putting a little more tension on the flapper door. hope that makes sense. if that works and you want a more permanent solution a tiny spot weld would do and then u can just grind it down to where it fits nicely without vibration.

 

OH! Alright I see what you're talking about. What wire did you use to do it? I'm assuming that I'll have to find a really thin piece of wire, that will be able to handle the temperatures emitted from the turbine.

 

i just used some cheap aluminum framing wire. costs like a buck of 2 at any hardware store and they have a variety of gauges. holds up to the heat fine and is still somewhat manageable after many heat cycles. i'm sure you'll find something that'll work.

 

Will do. I'll check back with updates. Thanks.