How to determine if waste gate actuator gone bad?

[SS_Sean]

Just as the title says....I'm trying to trouble shoot and over-boosting issue, and I suspect the actuator might have gone bad. What is your method to determine good/bad? I'd imagine a pin-hole would cause serious problems..

 

[mikestertwo]

Just as the title says....I'm trying to trouble shoot and over-boosting issue, and I suspect the actuator might have gone bad. What is your method to determine good/bad? I'd imagine a pin-hole would cause serious problems..

I just put regulated air pressure (about 25lbs) on the actuator and see if it moves and listen for any air leaks. Also check it for binding. The actuator could be out of alignment with the wastegate arm.

 

[GNVYUS 1]

Did you port the new turbo's exhaust puck hole?

If you take the hose off the actuator it will run only 12psi, you can try that and see.

 

[SS_Sean]

I did not port the puck hole. I verified the puck was covering the hole. It didnt matter where I adjusted the wastegate, the boost would skyrocket when I got on the loud pedal. I stuck a hand vacuum pump on the vacuum hose to the actuator and pumped it up. The actuator bled off almost immediately.

 

[salvageV6]

The stock wastegate actuator should start to move with 9psi. of pressured controlled/regulated shop air into it. Done moving out around 12-14 psi.

A HD. actuator starts moving around 12psi. of regulated air, not quite sure when it's done moving probably around 16-18psi.

Need regulated air and zip tied lines and a steady pressure and then listen for leaks in the diaphragm.

 

[SS_Sean]

Ok. Thanks. I'll look at this situation and report back.

 

[bison]

Remove it and submerge it in water and pressurize it. If it bubbles id replace it Make sure the swing valve is not binding

 

[Ttype6]

I stuck a hand vacuum pump on the vacuum hose to the actuator and pumped it up. The actuator bled off almost immediately.

There's a hole in the hose or the actuator is bad. Try the same test with a new hose. If the results are the same the actuator is bad.

 

[SS_Sean]

Could it be that I'm over-boosting because I have to port the puck hole to let more boost escape?? I spoke with Pete at PTE and he's indicating that this is what it sounds like to him...

 

[mikestertwo]

Could it be that I'm over-boosting because I have to port the puck hole to let more boost escape?? I spoke with Pete at PTE and he's indicating that this is what it sounds like to him...

If the problem just started without making any changes then I would say no, you have another issue. If you made changes that would increase air flow through the motor then I would say yes you may have to port the waste gate hole. Are you getting boost "creep" or does it immediatley over boost when you get on it? How high does the boost go?

 

[SS_Sean]

This has been a problem since I put the new motor/turbo combo on the road. The boost is fine, as far as performance goes...it's just that I have no adjustability in the boost with the actuator. The car is bouncing off 27-30 pounds of boost right about 3800-4000 rpms no matter what I try and do with the actuator. It has already cost me a set of head gaskets.

 

[Aztlanahauc]

Don't mean ti hijack the thread.

My Turbo-T seems to overboost also. My set up is 99% stock. I have a new wastegate solenoid and wastegate actuator line-the Y looking set of vacuum lines.

When I changed the headgaskets I noticed that my waste gate actuator was fill with oil. I think the oil broke down the rubber diaphram. I see 15 plus pounds of boost according to the stock boost gauge. I hope to have a 30 pound gauge installed this weekend.

 

[mikestertwo]

This has been a problem since I put the new motor/turbo combo on the road. The boost is fine, as far as performance goes...it's just that I have no adjustability in the boost with the actuator. The car is bouncing off 27-30 pounds of boost right about 3800-4000 rpms no matter what I try and do with the actuator. It has already cost me a set of head gaskets.

It sounds like you may have to port the waste gate hole. Just for grins, what happens when you disconnect the actuator from the waste gate? How much boost will it make then?

 

[87WE4BOOSTED]

If the problem just started without making any changes then I would say no, you have another issue. If you made changes that would increase air flow through the motor then I would say yes you may have to port the waste gate hole. Are you getting boost "creep" or does it immediatley over boost when you get on it? How high does the boost go?

I am having this same issue (boost creep) I did in fact place a new 160* tstat and a new RJC power plate. This is when I noticed the issue. Could this be my issue? I just ordered my new vaccum lines to see it this corrects it. If not I will go with the actuator. If problem is still there I will go with porting.

 

[bison]

I am having this same issue (boost creep) I did in fact place a new 160* tstat and a new RJC power plate. This is when I noticed the issue. Could this be my issue? I just ordered my new vaccum lines to see it this corrects it. If not I will go with the actuator. If problem is still there I will go with porting.

Your boost creep problem is related to the extra airflow the engine has. The thermostat and plate are not contributors to this problem. Open the hole up to .110-.120 and it should go away.