How to rebuild wastegate
09-20-2006, 04:48 PM
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How to rebuild wastegate
Ok another question?? What parts do I need to rebuild the wastegate and from were to order. My car is not boosting and the wastegate has been sitting for 4years plus is oem..
Thanks
Mark
Thanks
Mark
09-20-2006, 09:31 PM
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Mark,
First lets look at the WG and see what it does. If you took the WG off of the car and blocked the hole what would happen? Your car would produce boost until the engine failed so we know what a WG that does not open would do. If the rubber diaphram in the WG has a leak or is not seated properly then you will get varing degrees of boost. As far as I can tell, there is no way for a bad WG to prevent boost except if the WG valve is stuck open all of the time. You can check this by removing the WG and turning it upside down and seeing if the valve into the bottom of the WG is open. It will be a valve and there will only be a small amount of open space around the outside area of the valve. If there is a space then your WG has a failed spring and has failed in the open position. Putting about 15 to 20 psi from an air hose to the lower hose on the WG after you remove it from the car will show if the valve moves upwards or opens. If it is already open then you need a new spring and maybe a new diaphram. Pelican or any other Porsche supplier can sell you these parts.
The WG is not a magic part. It is simply a blowoff valve set to release excess pressure set by a spring. There are only two parts that should need to be replaced and they are the spring and the diaphram. If the valve guide has excess leakage then you might just want to get a new WG. In the short term, you can just block off the WG exhaust pipe with some kind of a stopper (Raw potato) and see if you can produce boost, (Carefully). If you can, then you know that the WG is wide open all of the time and needs to be repaired/replaced.
I know this seems a little basic but some people think that a WG is right up there with headers or a big IC. Its not. It opens and it closes at a preset pressure and if it functions properly thats all it does.
First lets look at the WG and see what it does. If you took the WG off of the car and blocked the hole what would happen? Your car would produce boost until the engine failed so we know what a WG that does not open would do. If the rubber diaphram in the WG has a leak or is not seated properly then you will get varing degrees of boost. As far as I can tell, there is no way for a bad WG to prevent boost except if the WG valve is stuck open all of the time. You can check this by removing the WG and turning it upside down and seeing if the valve into the bottom of the WG is open. It will be a valve and there will only be a small amount of open space around the outside area of the valve. If there is a space then your WG has a failed spring and has failed in the open position. Putting about 15 to 20 psi from an air hose to the lower hose on the WG after you remove it from the car will show if the valve moves upwards or opens. If it is already open then you need a new spring and maybe a new diaphram. Pelican or any other Porsche supplier can sell you these parts.
The WG is not a magic part. It is simply a blowoff valve set to release excess pressure set by a spring. There are only two parts that should need to be replaced and they are the spring and the diaphram. If the valve guide has excess leakage then you might just want to get a new WG. In the short term, you can just block off the WG exhaust pipe with some kind of a stopper (Raw potato) and see if you can produce boost, (Carefully). If you can, then you know that the WG is wide open all of the time and needs to be repaired/replaced.
I know this seems a little basic but some people think that a WG is right up there with headers or a big IC. Its not. It opens and it closes at a preset pressure and if it functions properly thats all it does.
09-21-2006, 02:25 PM
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I tested mine by blocking the muffler outlet and checking for any gases from the wastegate dump pipe with the engine running. You could get an assistant to rev the engine as well.
