What year is my engine?

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Jul 15, 2018 | 06:11 PM

nickfancher1

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Member

Joined: Aug 2014

Posts: 132

Likes: 2

From: Phoenix, AZ

Year: 1996

Model: Cherokee

Engine: 4.0L

What year is my engine?

Now I'm wondering if my Jeep has a newer motor in it, judging by the sticker on the valve cover. 2001?

It was owned by the State of Arizona from new until 2007 at 100k miles when my grandfather bought it at a state auction, I bought it from him in 2016.

1/2 way down the head on the driver's side there's a mark that says "0630" and then further down it says "H08".

Jul 15, 2018 | 09:30 PM

fb97xj1

CF Veteran

Joined: Dec 2015

Posts: 3,038

Likes: 338

From: PA

Year: 1997

Model: Cherokee

Engine: 4.0L

From what ive read on various Jeep forums, the "7" in 7801 is the year. So, 1997. The rest of it (in your case, the 801) nobody seems to know for sure how it decodes. That doesnt mean the engine itself is 1997 tho as the valve cover couldve been replaced. Look for a flat spot on the passenger side of the block, just above and to the right of the distributor, with numbers on it. For example, 701MX01.

The 1st digit is the year (7 = 1997)
The 2nd digit is the month (01-12)
The 4th and 5th digits are the engine (MX = 4.0 Liter)
The 6th and 7th digits are the day the engine was built (01 - 31)

The 0630 next to the valve cover is for the cylinder head.

Last edited by fb97xj1; Jul 15, 2018 at 09:35 PM.

Jul 16, 2018 | 12:58 AM

nickfancher1

Thread Starter

Member

Joined: Aug 2014

Posts: 132

Likes: 2

From: Phoenix, AZ

Year: 1996

Model: Cherokee

Engine: 4.0L

Thank you for your help. Engine code is 608MX14, and door sticker says build date for the Jeep was 8/96.

Jul 16, 2018 | 06:49 AM

cruiser54

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Posts: 43,971

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From: Prescott, Az

Year: 1990

Model: Cherokee (XJ)

Engine: 4.0

Quote:

Originally Posted by nickfancher1

Thank you for your help. Engine code is 608MX14, and door sticker says build date for the Jeep was 8/96.

August 14, 1996

4.0 Engine date codes

The date code is on the passenger side of the engine, on the block, just forward and up from the distributor on a machined flat surface.

The digits of the code identify:
 1st Digit-The year (8 = 1998).
 2nd & 3rd Digits-The month (01 - 12).
 4th & 5th Digits-The engine type/fuel system/compression ratio (MX = A 4.0 Liter (242 CID) 8.7:1 compression ratio engine with a multi-point fuel injection system).
 6th & 7th Digits-The day of engine build (01 - 31).
1. FOR EXAMPLE: Code * 801MX12 * identifies a 4.0 Liter (242 CID) engine with a multi-point fuel injection system, 8.7:1 compression ratio and built on January 12, 1998.

Last edited by cruiser54; Jul 16, 2018 at 06:51 AM.