I just bought a 2000 vitara w/ 87k mi for a 2.0L engine swap into a 1st gen Tracker. At start-up, it makes the timing chain rattle, which quiets pretty quickly. The noise never really goes away, but you really have to put your ear close to the front of the engine to hear it after it's been running for a little while.
So my question is, should I go ahead and replace the timing chain and tensioners while I have the engine out of the vehicle? And while I'm at it, what else should be replaced? Water pump, oil pump, anything else?
Alternatively, I'm wondering if I should just give it an oil change with a good filter and some 5W30 synthetic and see if it quiets down. When I run my finger around through the oil fill cap I pull up some sludge, so I suspect this car was not serviced regularly. I searched around on this forum and some people have reported that changing weight or grade of oil made a difference and the noise stopped. The other thing to keep in mind is that this going into a mostly trail rig. It will see some very hard miles, but only in small doses. I think I've put 3000 mi on it in the past 4 years.