Can you guys give me some specific guidance on where to find this hand written engine build date? I can't figure out if I need to open the hood or crawl under. And is it at the front or back of the engine? Is it near the oil pan?

 

Lanslide,

It's under the JK. Get on your back and slide under the Jeep from the front. Keep sliding just past the radiator until you see the pulleys which are above the handwritten date on the engine block. It is written upside down.

 

My JKUR build date march 2012 engine build date January 2 2012 just had driverside head and lifters replaced.

 

Thanks, Wendy!
My 2 door JK12 numbers are:
2012 03 07 on engine ...and my date of manufacture is May 12

So far...I couldn't be happier with the performance of my Jeep with 2,100 miles on it.

 

Detonator...how's is running?

 

Found the penastar engine serial number location, it's in the page section ( Other Pentastar V6 engine notes ) The serial number is on the left side of the block, at the transmission flange.

Read Here:
Pentastar Engines: Overview and Technical Details


I don't know if the serial number will tell you what head, AA or AB but at least you will have the serial number info !

33

 

Okay, I'm missing something here. I see Roller rockers, valves springs and keepers, and valves themselves. I don't see any hydraulic lifters. Are they in the spring itself? and if not, exactly what is the dealer really replacing? Or is all that BS too?

 

My old eye's might be seeing things but I hope it's there where I marked it
In the real world I would call it a cam follower hydraulic dampener instead of a lifter like whats in a push rod engine.

33

 

Yeah I saw that, but I think its further back. Plus I don't understand what benefit it would have in that location. I guess I can't look past the pushrod days.

 

It's running great so far. The tic is gone and it once again sounds like a new one. Slight improvement in fuel mileage and the hesitation in the first three gears is no more.