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Discussion Starter #1
Hi!

My car is no longer building more than 1psi of boost. Idles perfectly and makes no weird sounds. Just won’t build more than 1psi of boost.

The wastegate rod slides in and out very easily, the nut is still on it.

I’ve replaced the wastegate vacuum solenoid cable with a new connector and checked all fused to no avail.

How can I test the wastegate vacuum and connector?

I had a welder tack welt my loose heat shield right before the turbo stop building boost.

Could it have shorted out my wastegate vaccum solenoid or something else?

I have a p0299 underboost check engine code.

Thanks for your help in advance.
 

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If the only thing done between working and not working was the welding that is definitely a prime candidate for the cause.

Other things that could have been damaged are the boost sensor and the ECM.

You will either need a true diagnostic scanner (Tech2, etc) or you will have to start replacing parts and hoping.
 

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Discussion Starter #3
If the only thing done between working and not working was the welding that is definitely a prime candidate for the cause.

Other things that could have been damaged are the boost sensor and the ECM.

You will either need a true diagnostic scanner (Tech2, etc) or you will have to start replacing parts and hoping.
If the ecm was damaged wouldn’t there be other things failing?

Where is the boost sensor?
 

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Welder damage (if that is what this is) can vary significantly depending on conditions. It is possible that the only thing damaged is the sensor or solenoid, or it could be the individual input or output that the device is connected too.

The advantage of the scanner is that you can look at actual sensor inputs, and can activate specific outputs. This makes diagnosis significantly more definite, and you aren't guessing as much.

The boost sensor is identical to the MAP sensor, and is on the charge pipe between the cooler and the throttle body.
 

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Discussion Starter #5
Welder damage (if that is what this is) can vary significantly depending on conditions. It is possible that the only thing damaged is the sensor or solenoid, or it could be the individual input or output that the device is connected too.

The advantage of the scanner is that you can look at actual sensor inputs, and can activate specific outputs. This makes diagnosis significantly more definite, and you aren't guessing as much.

The boost sensor is identical to the MAP sensor, and is on the charge pipe between the cooler and the throttle body.
I used the trifecta code scanner and found a useful code!

p0243 wastegate solenoid. Is there anyway I can test the solenoid or connector wiring?

I had this issue before and ordered a new connector and soldered it on. That solved it.

I checked the connector soldering and it looks good.

Is there a way to easily test the solenoid or connector? With a voltmeter and the car running?
 

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I'm sure there is a way to test it, but do not have access to a service manual at the moment. Checking continuity through the coil comes to mind as a first thought.
 

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There is no test procedure documented for the solenoid. The test is for the control output from the ECM with the assumption that if the control output is good, the solenoid is bad. Testing requires commanding the solenoid to 50% and checking for the PWM output with a test light. The output is commanded to 0% at idle, so a Tech2 or equivalent is required.
 

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There is no test procedure documented for the solenoid. The test is for the control output from the ECM with the assumption that if the control output is good, the solenoid is bad. Testing requires commanding the solenoid to 50% and checking for the PWM output with a test light. The output is commanded to 0% at idle, so a Tech2 or equivalent is required.
Gotcha, I got ahold of a new wastage solenoid (part # 12633355) to try out.

However, it’s different than the one I currently have on the car.

What hoses go in where?? I don’t even think the new bracket will fit. Going to need to reuse the one currently on the car?
 

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Well...I've learned something. I didn't know our cars had 2 of these...
 

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The_Ghost it does not it is a single piece with 3 connections. Solstice503 from your 1st picture and your line drawings you are connecting the correct way.
 

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There was a way to blow through one of the connectors, then energize it with a 9v and blow through again, but I can't find the video.

@JohnWR...there is one on top of the intake as well....aren't there 2?? The one under the turbo is the wastegate, the one on the intake is the BOV....I think.

You might have a bad turbo. Does the impeller shaft have any play in it? Does it spin freely?
 

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There was a way to blow through one of the connectors, then energize it with a 9v and blow through again, but I can't find the video.

@JohnWR...there is one on top of the intake as well....aren't there 2?? The one under the turbo is the wastegate, the one on the intake is the BOV....I think.

You might have a bad turbo. Does the impeller shaft have any play in it? Does it spin freely?
If the solenoids are the same, then I don’t think I need to test them anymore since it’s brand new.

I’ll re check the wiring on the plug. It happened right after the welding job, so I feel like it would be an electrical issue and not mechanical.

I’ll check tomorrow if it spins.
 

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.......
@JohnWR...there is one on top of the intake as well....aren't there 2?? The one under the turbo is the wastegate, the one on the intake is the BOV....I think.
.......
The solenoid on the intake that I know of is the Evap Purge Solenoid. Nothing to do with the turbo.
 

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If the solenoids are the same, then I don’t think I need to test them anymore since it’s brand new.

I’ll re check the wiring on the plug. It happened right after the welding job, so I feel like it would be an electrical issue and not mechanical.

I’ll check tomorrow if it spins.
So the turbo blade spins freely in both directions.

I soldered the connector (replaced last month) and checked for visible tears/leaks in the hoses nearby and found none.

Still only seeing 1 psi of boost :(
 

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To clear it up, this is what I was talking about. There is one under the turbo (wastegate???) and one up on the valve cover on the intake (BOV???). One hose goes to intake after air cleaner, the other goes to cool charge tube and the other goes to intake itself.
107254
 

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To clear it up, this is what I was talking about. There is one under the turbo (wastegate???) and one up on the valve cover on the intake (BOV???). One hose goes to intake after air cleaner, the other goes to cool charge tube and the other goes to intake itself. View attachment 107254
Yep, they look like the same part apart from the mounting bracket and slots for the brackets.

The original bracket doesn’t fit the new part.

Could this mean there not interchangeable?
 

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