Has anyone ever experienced a wastegate actuator failure? When I apply pressure to the line to the actuator it all leaks out without engaging the actuator.

Here's the whole story:

I just replace the twins with a used set. While I was in there I plumbed in an electronic boost controller. I did not wire up the boost controller yet, I am trying to track down an engine performance issue, so I thought I would wait until I found that problem and then I could finish the boost controller install.
I tee'd the two lines coming off the turbo, then ran that single line to the stepper motor. Then I ran that line and tee'd it to the two lines going in to the actuators. Then I plugged the two nipples coming off of each of the actuators.

It worked fine the first time I drove it, I had a 7/6/7 boost pattern, which in my brain is correct for no pills and no restrictions. I was testing the O2 sensor for problems the other day, and all of a sudden I have uncontrolled boost. It hit 15 lbs at one point. Scared the bee jeezus out of me.

By the way, 93 Fd, stock except for the intake, Y pipe, hi flow cat.

So, today I put pressure on the line that goes to the two actuators, and it does not engage the actuators, in fact you can hear the air just leaking right back out. So, I am wondering if anybody has ever seen this kind of problem before? I assume that there is some sort of rubber type diaphragm inside those actuators, and maybe the wastegate actuator failed.
Any thoughts?

 

I have a similar problem only that my actuator is not leaking, but I never activates, my car has boosted to 15psi but it seems like when I let go of the gas the pressurized air in the intercooler kind of pushes back to the turbo and BOV making a choppy discharge.

 

The caps you put on the nipples are leaking already.

It happened to me also.

 

Any suggestions for a good way to plug them?
I am using the standard rubber plugs you buy at the parts store, and then I zip tied them.

 

According to Dale Clark, the EPDM caps from McMaster-Carr are much more durable.

Another option for now is a short hose with something solid (golf tee) plugging the end.

 

Ok, I will order some of the EPDM caps, and in the meantime I will try the hose, golf tee method.
But, I am going to do some additional testing, because I sprayed soapy water on the plugged nipples, and did not see any bubbles. That doesn't mean they arent' leaking, but I can hear the air leaking out, and it sounds like it's coming from behind the actuator.

 

It's entirely possible for the actuators to be leaking. It's very unlikely though that both have developed a leak at the same time.

Regular vacuum caps definitely break down in a hurry in this environment. Mine probably had 1000mi on them when they burst. Both at the same time in fact. I still have hoses with golf tees in them because I haven't had reason for an order to McM yet.

Dave

 

I think only one of them is leaking. The wastegate actuator. They are plumbed together for the boost controller. This is correct isn't it?
I like the advice of the hoses and golf tee. But, as far as leaking, the plugs have about 10 miles on them is all. I think I will isolate the wastegate act., install hoses with golf tees, and test it to see if that cures it. IF not, I will replace the actuator with one from my old set of turbos.

 

Since you have a spare actuator then yeah I'd do it exactly as you described.