Greetings all. I have a 1997 F150 with a 4.6 L Windsor engine, it has 154000 miles. I've had to remove the heads to replace the head gaskets and this site has been a great place for me to find tips and tricks that aren't in the manuals. I'm getting ready to put everything back together, and I'm wondering if I should replace the timing chains and tensioners. I noticed while cleaning them that one tensioner the top of the piston is rounded and I'm able to move the piston by hand. The other the top of the piston is nearly flat and I can barely move the piston at all. I'm wondering if one or both of the tensioners are bad. Thanks.

 

I would replace both of them as well as the guides. How many miles are on it?

 

154,000 give or take a couple hundred.