I'm posting for my brother who owns this Explorer. As he went to lunch yesterday, he noticed his Explorer started running odd. Wanted to die a few times, lost power. He made it back to work fine, but on his way home it developed a harsh rattle from the top of the engine. While driving, he thought it was an exhaust leak. Got out of the vehicle when he got home and realized it was something worse.

When I made it to his house to look at it, the engine was still warm and the rattle was still there. Changed the oil with a Motorcraft filter (had a Fram on it before.) Started it and it sounded fine for about 20 seconds, then the rattle slowly came back. I've read a lot about the timing chain and tensioner issues, but not sure if this is it or not. Most of those issues sounded RPM specific, where once this starts rattling, it's always rattling. It also seems to lack power and has a random misfire. I started and stopped it in 30 second intervals this morning and it got to the point where I would have to hold the accelerator to the floor in order for it to start. Where should I start?

 

Take a video of it running, I would like to hear the rattle. Its possible one of the chain guides broke.

 

How do I post attachments on here? It won't let me.

 

You need to upload the video to a video sharing site, then link to the video in a post.

-Rod

 

Hi all. Took the intake and driver's side valve cover off. Before I took it apart, I started the engine and it was quiet for about 10 seconds, then started making noise again. The sound reminded me of a cam jumping into place when you're using a ratchet to crank it over (removed from the block of course.) First thing I looked at was the chain cassettes/guides. Nothing appears to be broke. However, the chain appears to be very loose. I can crank counter clockwise on the cam, and push the cassette against the chain, creating about a 3/8" or more gap between the tensioner rod and the cassette. I took the tensioner out, and it does have spring pressure. However, how far should it push out? It just seems like if it would come out another 3/8" or so, then it would hold the chain tight.

When you shut the engine off, it's like you can hear the cam jumping into place as it slows down. The noise follows RPM. Could the chain be so loose that whenever the chain does pull on the cam gear, it has so much slack on the back side that it allows the cam to jump ahead of the crank/chain? I guess a stretched chain could be the culprit, but why would it happen all of a sudden? It went from running perfect to this in a matter of 10 miles of driving.

At a cold start, there is no noise and the engine runs great. Once it starts to make noise, it starts hesitating. If it starts hesitating and you give it throttle, you can hear it pop back through the intake.

Any other ideas?