'99 JGCL solutions: Trans (0720), Sluggish Start, Overheating

[mthomason]

1999 Jeep Grand Cherokee Laredo, 4.0L 6 cyl., Automatic, Selec-trac, 58K miles

I had three prevalent problems with my GC that have now been resolved:

1) the transmission randomly would not shift out of 1st (low) gear -- it gave a code of 0720. The output shaft speed sensor was replace and the problem and code have been resolved (thanks posters!). Note that the transmission/drivetrain still "clunks" when put into gear -- even my old '86 Grand Wagoneer did that.

2) the engine kept overheating while sitting in traffic; no failure code was given. However diagnostic work pointed to a failed fan relay. The relay was replaced an now no overheating has ocurred in the now warmer weather (thanks posters!).

3) the engine was becoming sluggish to start. Sometimes it would take three trials with the starter (about 2-3 seconds each before starting). A seal kit was installed by my Jeep dealer -- information from a technical service bulletin about pressure leaking after the engine was turned off. The parts were cheap (about $ 20), but the gas tank had to be dropped to perform the work. It is now starting just as when new.


The preceding is just a little FYI for those having similar symptoms that I had....