NCRaineman

Greetings.

I'll start with the basics.

2005 4.0L automatic, 47,xxx miles (Yes, really.) Bone stock, no mods.

Last week I noticed a pretty nasty rattle coming from underneath the car on the passenger side. Not present at idle but loud and very noticeable around 2k RPM, above that it stops. Car idles smoothly and otherwise runs just fine. Got up under it and looked around, no leaks and everything is tight.

Now I'm fairly handy with a wrench and have a passing familiarity with the 4.0 from owning a Ranger back in 2001. If memory serves 4.0s from the early 00's had an issue with the timing chains and there were some related TSBs for fixes put out. I was under the impression that this issue had been resolved by the time the 4.0 found its way under the hood of Mustang.

Is timing chain what I'm likely looking at here? Not exactly relishing the idea of having to crack the engine open with less than 50,000 miles on the vehicle.

Thanks!