Post by Stinger on Aug 4, 2012 22:46:40 GMT -5
Boost/Vacuum leaks cause a ton of problems with 2.3T engines so pressure testing is very important. Even engines that seem to be running OK will typically have boost leaks somewhere when tested and will run better once those leaks are fixed. To pressure test the system, you get a pressure tester (either home made or one you buy) and install it on the inlet of the turbo.
A cheap home made pressure tester looks something like this:
A more expensive (though still relatively cheap) looks something like this:
Once installed, you use an air compressor regulated down to 20psi and blow air into the engine. Be sure to shut off the air compressor so it doesn't kick on after a few seconds and start making noise, making it much harder to find any leaks. Then if there are any large leaks, you'll most likely be able to hear it and locate it that way. If they are smaller, you'll need to find them by feeling along all of the IC tubes/couplers, throttle body seals, IAC valve, TPS, intake gaskets, and injector o-rings to feel the air leaking out. Also check all the vacuum lines.
To find any leaks in the vacuum lines an easier way, you'll need a vacuum gauge. Then with the engine running, note the amount of vacuum. Then either pull off and plug one hose at a time from the vacuum tree and see if vacuum increases (indicating a leak in the hose you disconnected) or decreases (you created a leak by not plugging the open port on the vacuum tree properly). Once you've found which vacuum hose(s) increase vacuum when they are unplugged from the vac tree, plug it back in and trace that line, checking for leaks along the way. Don't stop until you find all the leaks and get the vacuum up as high as it was when you unplugged the line from the vac tree.
A cheap home made pressure tester looks something like this:
A more expensive (though still relatively cheap) looks something like this:
Once installed, you use an air compressor regulated down to 20psi and blow air into the engine. Be sure to shut off the air compressor so it doesn't kick on after a few seconds and start making noise, making it much harder to find any leaks. Then if there are any large leaks, you'll most likely be able to hear it and locate it that way. If they are smaller, you'll need to find them by feeling along all of the IC tubes/couplers, throttle body seals, IAC valve, TPS, intake gaskets, and injector o-rings to feel the air leaking out. Also check all the vacuum lines.
To find any leaks in the vacuum lines an easier way, you'll need a vacuum gauge. Then with the engine running, note the amount of vacuum. Then either pull off and plug one hose at a time from the vacuum tree and see if vacuum increases (indicating a leak in the hose you disconnected) or decreases (you created a leak by not plugging the open port on the vacuum tree properly). Once you've found which vacuum hose(s) increase vacuum when they are unplugged from the vac tree, plug it back in and trace that line, checking for leaks along the way. Don't stop until you find all the leaks and get the vacuum up as high as it was when you unplugged the line from the vac tree.