In un sito americano che raccoglie pregi e difetti delle auto ho trovato sul Grand Cherokee annata '94:

Service/Maintenance

Normal service and maintenance costs fall in the average category, with only the extra fluid changes for the 4-wheel drive stuff deviating from passenger car norms. Both the six and the eight are durable, long-lived engines. The six in particular has a track record of regularly reaching 200K miles without a rebuild. Assuming proper maintenance, of course.

Parts cost are fairly low, as the Grand Cherokee shares many individual components with other Jeep and Chrysler products.

Il che mi ha tirato su di morale, dato che 200.000 miglia senza problemi non sono uno scherzetto, ed ha confermato che, dal punto di vista dell'affidabilita', ho scelto il motore migliore 

Pero' poi c'e' scritto:

Reliability

Early Grand Cherokees seem to have more than their share of problems, and we recommend avoiding them. Among the trouble areas: transmission, axles, seals, body hardware and electrics. '93 and '94 was not a good time for many Chrysler products, and these are no exception.

Things got progressively better, and a '96-'98 model are a safer bet. Still, these are not the most trouble-free vehicles. Sure, they're durable, but that's different. The sheer volume and nature of technical service bulletins issued for the Grand Cherokee is disappointing -- the Grand Cherokee has so many charms that it's a shame that Chrysler dropped the quality ball.

Il che fa presumere che il fatto che finora vada da dio non e' che un'eccezione, e che ben presto qualcosa succedera'. 

http://www.vmrintl.com/Usedcars/Car%20%20Reviews/jeep_grcherokee_93-98.htm