Timing chain rattling from Engine

[Aquel45]

I have a 2005 Ford Explorer with a 4.0 SOHC while the engine is running the left side timing chain rattles. I replaced the timing chain and guides and tentioner, the engine has good oil pressure but the noise is still there has anyone had this issue before and is there a way to fix it?

[plymouthcranbrook]

Funny to find your post first thing as I am writing to get information about two Explorers with the 4.0 that have a either valve or timing chain noise. One is a 2004 with about 140,000 miles and the other a 1999 with 155,000 miles. My neighbor took the left hand cover off of one of them and found the rockers and valve area seemed dry. The 2004 doesn't make noise until it warms up and the 1999 does it all the time. Have you found anything else out?

[shorod]

Originally Posted by plymouthcranbrook

Funny to find your post first thing as I am writing to get information about two Explorers with the 4.0 that have a either valve or timing chain noise. One is a 2004 with about 140,000 miles and the other a 1999 with 155,000 miles. My neighbor took the left hand cover off of one of them and found the rockers and valve area seemed dry. The 2004 doesn't make noise until it warms up and the 1999 does it all the time. Have you found anything else out?

Others have explained that the timing chain tensioners can cause the rattle at cold start depending on which of the 4.0L V-6 engines you have. When you say the rockers and valve area seemed dry, do you mean they don't appear to be getting oil!?!

As for the original post, since the tensioners have already been replaced, I'm not sure what else to suggest other than to make sure the correct oil is being used and a filter with the anti-backflow valve is used. The OP may also want to substitute one or two quarts of oil for transmission fluid, run that for a few miles, then drain and replace with correct oil in case something is sludged/stuck in the valvetrain.

-Rod