not all 99-01 4.0s had the bad head (it's a 0331 head, btw). I have owned 3 different Cherokees with the 4.0, and it is a GREAT engine, no doubt. But IMO, if you are looking into getting a WJ Grand Cherokee (99-04), go with the 4.7 v8. It gets very similar mileage numbers as the 4.0 in the same application, has plenty more power, and is also quite reliable. My wife has had her '04 GC Laredo with the 4.7/A5 for over 5 years now, and we both love it. It has 115k on it (we bought it in '07 with 51k) and aside from maintenence items it has never given us any trouble. AWD high/low range works great, trans shifts fine, rides well, etc. My wife drives with a heavy foot and she averages 14-15mpg commuting (in town), average highway mileage is 19-20mpg at 75.
If you want to know more about the differences between the WJ model years, read up here:
www.wjjeeps.com
- Justin