I have a 2004 Endeavor with 66K on the clock which I have owned for almost two years now with no problems at all. I love it, I purchased it because of my great experience with my other Mitsu (2001 Montero Sport). However I am starting to hear a slight rattling sound upon acceleration on my Endeavor. It kind of sounds like a metallic rattling sound. Its not very loud but its getting annoying and when I am driving next to a wall I can hear it more. If I park the truck and give it gas I can usually hear it but less. My instinct tells me it could be a heat shield or something related with the muffler/exhaust piping. Any thoughts on this issue?
Another question, I am going to be getting my first Timing belt done at the local Mitsu dealer along with the serpentine belts replaced, and I wanted to know if there were other parts I should change along with the timing belt/belts to save on future labor costs.

Any info would be gladly appreciated

Mine has a metallic tapping but only when it's cold. Lifters sticking is my guess. But once it's warm I have no noise at all. Does the tapping increase in tempo along with rpm?

When you're having the belts done, have them change your plugs unless it's been done already. Have them check the cv boots, motor mounts and incase they don't, make sure they inspect the tensioner system for the timing belt itself. I'm sure they will, but I have known my fair share of bad mechanics.

WD

Possibly cooling system flush, change the transmission fluid.

I have the exact same sound. I've had it for a long time. A while ago it got worse, and I finally took it in and they removed the heat shield over the converter. The newer, worse/louder noise went away however I still have the original grinding noise upon acceleration, mainly up hill, under load. It just annoys me now, but I don't have much hope of it going away. Most mechanics won't actually get in the car and go for a ride even when you tell them, you need to be against a wall so it reverberates.

The noise on my ende is actually not evident upon a cold startup nor does it increase in tempo with the RPMs increasing. In fact I think I only hear it at lower RPMs. I am going to lift it next weekend and check the cat's heat shield as someone suggested and as I am also leaning towards an exhaust related issue. Does the ende have more than one cat and if it does do they all have heat shields? I am the cat/s are in the frontal part of the truck in back of the engine or are they closer to the actual exhaust? thanks guys

I has the same sound on my, turns out it was the Heat Shield. One side rusted loose. Easy and cheap fix was to buy a .99 3" metal clamp. I got mine in the plumbing section of local hardware store. Wrap this around the heat shield and just tighten the screw attachement built on the clamp.


No more metal sound upon acceleration.