My 03 Dodge Durango 4.7L engine was blowing white smoke from exhaust. Took the heads off and had them done at a machine shop. Assembled original timing chains, tensioners and guides and align chains per requirements.

Upon first startup engine ran fine but was knocking sound from front of engine. Removed valve covers and replaced 16 lifters upon startup same problem. Took apart timing chain cover and found drivers side timing chain loose. I am not sure where to go to next. Need help.

Answer:It sounds like one of the timing chain tensions is either faulty or was not installed properly. That is why the chain is loose and banging around. When using the old tensioners, you probably have to re-seat it, then after the chains are on, release it so there is tension on the chains. You would not have to seat a new tensioner, but you would have to release it once the chains are installed.

The other possibility is that one of the tensioners is just bad- is binding up and would need to be replaced. A timing chain tensioner that has been in a certain position for many thousands of miles can be bound up and stuck in that position.