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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
Polished up the #1 rod journal to clean off some of the junk, seemed to work pretty good! Also plastiguaged one of the mains and it was within spec at 0.002in.
I'd put the Plastigage perpendicular to the bearing to get a more complete read on wear. Also, did you jack up the crank while doing the reading? The weight of the crank must be relieved when measuring clearance if the engine is upright. See p. 9-3 in the manual for details.
Thanks! I'll try again later and post the results. That service manual is extremely helpful, it has pretty much every aspect of the whole vehicle covered.
So I just had all 6 pistons come in, weighted them, and they all came out to ~595 grams with the pin. I weighted one of the stock pistons and it was ~ 564. Why is there such a huge discrepancy? I don't know if I should just return the pistons or grind them down, but that's way out of spec.
Yes, with the pin the new pistons were ~595-600 grams while the old pistons were 564-570 with the pin. This was also JUST the piston and wrist
pin weight, no rings or rods. They were enginetech pistons and will be returned. I've ordered some sealed power pistons which claim to match the stock weight of 564 grams
Cause piston weight specifications are w/o the pin. 1998 should be 563 - 567 grams w/o the pin which, if you measured the stock piston w/o the pin is right on target.
Starting in 1999 the pistons less pin were 417 - 429 grams. What's the weight of the stock pistons w/o pin?
I'll have to check when I'm home, but I know it was in the 400 gram range when I measured it. With that said, why would my factory pistons+pins weigh less than the new ones?
I'll have to check when I'm home, but I know it was in the 400 gram range when I measured it. With that said, why would my factory pistons+pins weigh less than the new ones?
passenger side near the distributor. Up and a bit to the right. Engine date code.
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).
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.
