1991 Mitsubishi Galant VR-4
CoDSM Intake Leak Testing
This is just copied from an email description I wrote. Pictures coming soon.
Okay there is a VFAQ on leak testing but here is how I build a tester and
First an intake leak tester goes right on the inlet of your turbocharger
instead of you intake snorkel or pipe.
->-------------| *** turbo ------> to rest of intake system
hose to air |-
pvc or similar
Basically I take a PVC cap or similar piece of plastic, drill and tap an
hole, thread in a fitting to hold some line. Then that line goes to the
compressor source (regulated or inline regulator). The other side can use
the same coupler your intake pipe uses or a rubber one from Home Depot
racing. Whatever fits and seals, varies depending on your turbo.
Then you hook up the tester to the turbo and start feeding in the
compressed air (regulated to ~15 psi or so). Turn on the gauges (not the
car) so you can see what your boost gauge is reading. Add more air until
you are pretty steady at 15 psi (or whatever max pressure you run). Then
fill up a small squirt bottle with soapy water. Now trace through the
entire intake system and listen and squirt for leaks. Big ones you can
hear and feel with your hand. Smaller ones will be easily illuminated with
the squirt bottle. Check specifically all piping connections, welds,
intercooler, BOV flange and BOV itself, gaskets (BOV, TB elbow, TB,
intake manifold), Throttle body shaft seals, BISS. Whereever you leak do
your best to stop it. Ie new gasket, tighten connection, new BOV, reweld etc
When you finally (weeks later ususally) get rid of all the known leaks
test again. Then a month later test more. Basically test often and your
car will be running much better.