slack chain TDC
 

got timing chain installed ,while checking to make sure all marks line up right I noticed that the chain goes slack when engine reachs TDC then tightens again when you go past TDC, put in new tensioner?????.........
William Rogers.....

I've always read/heard that good practice always dictates installing a new tensioner when changing out the timing chain.

The only time I saw slack in the new chain was when the tensioner was out, or backed way off OR when moving the crank CCW the slightest amount.

I am unclear if you are asking about installing a new tensioner, or making comment about a new tensioner that is installed. By all means install a new tensioner with a new chain AND a new tensioner will not be providing tension (beyond the spring tension) until the engine is running and oil pressure is up.

Yes I have new tensioner installed and it is working on it's spring only.but tensioner relaxes when cycled to TDC with socket on crank nut as I check timing marks,am sure it will not do that when oil pressure is there but just couldn't figure out why it would relax every TDC, you can hear a fluid sound when you pass TDC and it retensions......
William Rogers.......