2.4 Timing

Recently had to replace the Timing housing on my 01 grand am (2.4), Had to remove the timing chain and Cam sprockets. Put it all back together the way it came out, all timing marks line up and the chain is tight between the cams and crankshaft, The tensioner is the piston type and I assumed that was pressurised by the oil pump when started up. When i put it all back together and started it up the timing chain was making noise like it was loose. I tour it back apart and looks like the piston never was pressurized. So of course the tensioner never tightend the chain up. Is there a trick to the timing on these or what? car runs fine, except for the sound, Im sure the timing is right!

The piston has to be depressed forcefully and then simultaneously released for it to engage / compress the chain. You can achieve this by using a pair of vice grips, and rocking off the top vice after it is compressed.