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Discussion Starter · #1 ·
i have a 1991 2.5 but ik the PO swapped the motors so I'm wondering where the engine year is located ??
 

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"The engine ID number on four-cylinder engines is located on a machined surface on the right side of the block between the number three and four cylinders..."

Haynes Repair Manual
Jeep Wrangler 1987 thru 2000 All Models
Page 0-5
 

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Discussion Starter · #3 ·
"The engine ID number on four-cylinder engines is located on a machined surface on the right side of the block between the number three and four cylinders..."

Haynes Repair Manual
Jeep Wrangler 1987 thru 2000 All Models
Page 0-5
that tells me what year it is ?
 

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It is basically a six position, date stamp.

Position 1 = year (1= 1991, 9= 1989, etc...)

Position 2&3 = Month ( 01= Jan, 12= Dec, etc...)

Position 4 = engine type (no clue as to example)

Position 5 & 6 = Date (01= 01, 31= 31 etc...)

Keep in mind that engine plants ran on a CALENDER year.
And assembly plants ran on a MODEL year.

It is perfectly normal for a jeep to have a previous year engine, in fact half of them do.
The manufacturer changes to a new model year in around July and
the engine plant is still using the real calendar until DEC 31st.

If you have your original doors, there is 'MDH' assembly date located in the drivers door.
That date should be closer to your Engine ID date.
I'd say no more than a week apart.
 
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