4.0 liter Engine I.D. #

[1992EliminatorSWB4x4]

My 1992 jeep Eliminator has a 1995 Mopar Oil Pan tag on the decal sticker attached to the  oil pan. To the right of the distributor on top of the engine short block it has these numbers,   I 39 MX I6   stamped into the engine.  Is this a 1992 engine, I do know it is an H.O. engine. Thanks.

Bill   from  Alabama

[Eagle]

Engine codes:

 

1st digit = year (8=1998, so 1 =1991)

2nd & 3rd digits = month (01 - 12)

4th & 5th digits = Engine type (MX = 4.0L, HX = 2.5L)

6th & 7th digits = Day of build (01 - 31)

 

 

From 2000 FSM

[1992EliminatorSWB4x4]

Thank you, for the info. Guess mine just has a newer oil pan, must have been changed, at least its a Mopar pan.

[JH4020]

The digits on a motor I have read 104C03. What does the "C" stand for?

[Area51Werks]

Thanks for the info. My 91 had an engine swap. Very stock job under the hood. If I hadn't have been told it was swapped I would have never known. The block shows the first number is 5 and it is an MX so that's good right? Did they have the HO engines in 95?

[gogmorgo]

All '91+ can be considered HO's, although they were only OBD1 until '96(?). '95 will be pretty well the same as a '91 with a couple small changes.