'07 Navigator; clatter at startup, quiet while running. 120k miles. I recently got this vehicle and I don't know its history.

I pulled the covers off and found the left bank had a small chunk broken off the tensioning guide, so I assume the tensioners are bad, allowing the chains to slap at startup.

The biggest concern, though, was that the phasers are stamped L on the passenger side and R on the driver's side. From what I can tell, some aftermarket phasers aren't sold bank-specific, so it could be that they've been replaced in the past and I don't have an issue at all, but I wanted to verify with someone more familiar with this engine than me.

Since the phasers aren't ticking and appear to be in good condition (apart from their locations being reversed), do I need to do anything with them? I'm inclined to just line up the new chains with the marks and put it back together.

 

The phasers have a L and a R on each one, they are the same part for both sides. Turn the engine 360 degrees and you will see the other marks. Read my posts in this thread to set the chains up properly.

 

Thanks for the input. I found that there were marks on the other side like you said, and I had removed the chains with #1 TDC exhaust. I reinstalled the chains, turned the crank 360 degrees, saw the correct marks on the phasers, and installed the new chains without issue. I counted links to be sure it was timed right, turned the engine over by hand several times, and counted links again just to be sure.

Now I'm in the process of putting it all back together which, so far, seems to be going faster than taking it apart...