Bad waste gate
09-16-2006, 01:59 PM
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Bad waste gate ??
When I disconnect the sensing line from the outlet of the turbo, should I be able to blow through it? I was going to hook up an air source to check it's operation but, If I can blow though it, I'm thinking the diaphragm is shot.
The next question is, on a bone stock 235hp ISB, how high can the boost go if the wastegate isn't working?
I'm pretty sure I hear a leak when climbing hills, and power is not what it should be.
Hypothesis is that the diapragm went and that lead to something else coming apart on overboost.
Any input is greatly appreciated.
The next question is, on a bone stock 235hp ISB, how high can the boost go if the wastegate isn't working?
I'm pretty sure I hear a leak when climbing hills, and power is not what it should be.
Hypothesis is that the diapragm went and that lead to something else coming apart on overboost.
Any input is greatly appreciated.
09-18-2006, 12:44 AM
#3
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I'm assuming you have a manual transmission (the automatics have a hardlined to the wastegate). Not sure if you can blow through the line or not. Max boost on a stock engine should be around 22 psi. If the wastegate were stuck open, then the engine would be blowing black smoke out the tailpipe, seriously reduced power, poor mileage, and your EGT's would be through the roof. This would happen since the heat energy and exhaust gas is bypassing the turbine.
If the wastegate were stuck shut then the engine would overboost and defuel (to bring the boost pressure back to normal), and would also trip a fault code and turn on the check engine light.
Now if you blew an intake boot it would be the same as a wide open wastegate except that you would build some boost and have a lot of intake noise. You would have black smoke and reduced power as well. I would inspect your intake boots close and pressure test the system if possible.
Hope this helps. Please let us know what you find.
If the wastegate were stuck shut then the engine would overboost and defuel (to bring the boost pressure back to normal), and would also trip a fault code and turn on the check engine light.
Now if you blew an intake boot it would be the same as a wide open wastegate except that you would build some boost and have a lot of intake noise. You would have black smoke and reduced power as well. I would inspect your intake boots close and pressure test the system if possible.
Hope this helps. Please let us know what you find.
09-18-2006, 07:42 AM
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What I found was a blown diaphragm on the wastegate actuator.
Did the pressure test and found a couple of leaks at the clamps on the boots.
Leaks are fixed, hoping to pick up a new actuator today at Caledonia Diesel (Laying over in Western NY to make repairs).
So, the computer will defuel on overboost?
That's good news.
Explains the way it felt and why if I caught it just right it would still climb a hill.
The ISB's are new territory for me. Looking forward to learning more.
Did the pressure test and found a couple of leaks at the clamps on the boots.
Leaks are fixed, hoping to pick up a new actuator today at Caledonia Diesel (Laying over in Western NY to make repairs).
So, the computer will defuel on overboost?
That's good news.
Explains the way it felt and why if I caught it just right it would still climb a hill.
The ISB's are new territory for me. Looking forward to learning more.
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