I Had An Older Intrepid With A 3.5L And A Newer One With A 2.7L. Both Were Great Cars. The 2.7 Intrepid Was My Wife’s And She Loved Driving It (For Many Years).
The earlier 2.7s did have sludge issues for people lacking maintenance sense. Mine didn’t. Some also had problems with timing chain guides. Mine didn’t (probably a maintenance issue, also).
The 3.5s were nearly bulletproof, smooth and powerful. No bad habits (one exception - earlier ones did have intake gasket issues - easy minor repair) Great motor. I don’t know if the newer ones (2004) are basically the same engine or not. Check that out.
The 2.7L has a timing chain. My 3.5L had a timing belt that I replaced twice while I had the car. I believe Chrysler recommends 120,000 mile intervals for changing it. A neglected belt breaking can practically destroy an engine. The water pump, tensioner and idler pulley should be replaced with the timing belt and possibly the crank seal.
The car you’re looking at is overdue for a t-belt change if it’s got one and has never been changed. I did my timing belts myself after purchasing a couple of special tools and making a couple (one was for crank seal).
It scares me a bit that the selling price is only $1000 unless you’re getting a deal from a relative or somebody you know personally. The car should fetch more money.