highest mileage out of 1997 4.0?

[pierceME311]

I just did the rear main on my early 98, 145k (mostly 97 parts) and I have had it since 74k and only use the cheap wal-mart brand oil since I've got it and I go to 5,000 between changes and it had no sludge to speak of, doesn't burn any oil and has no ticking. I've always been under the impression that the I6 was built to be a pack mule and not a race horse, as such, I treat it that way.

 

[kastein]

The engine is pretty much all the same throughout the years. The '00 and some early '01's had a bad casting, and the block cracks sometimes. The older ones used a renix system, but many of the parts are the same. Its the computers and OBD systems that are the biggest change between the years.

They all last long.

I believe some late 99s had the crappy casting as well, not sure.

I daily drive my rustbucket with 136k and counting (engine still going strong) and I have been helping restore a 91 MJ with over 200 on it, engine has a fairly loud ticking which I believe to be rockers but starts faster than mine even in the cold. The PO was of the "don't fix it till it breaks, then use the absolute cheapest stuff you can to fix it till it limps again" mentality* so we have been playing catch-up with replacing all the nearly broken stuff on it, but for 600 dollars it was well worth it. I expect both to make it to 300 easily.

* example: half a dozen patches on the transmission cooler lines, all done with vinyl hose and hose clamps more suited for use on an aquarium - to avoid spending $63 on all new OEM equivalent lines.

 

[Red97XJ]

so anyone have any blow up stories on the 97ish 4.0's????

mileage, why, what it did, etc.

 

[SleeperXJ]

My 99 has 297K, still runs strong. Only leak is the RMS (typical). No spoke and engine still quiet (well as quiet as it was when it was new).

 

[dagr8tim]

My 99 has 297K, still runs strong. Only leak is the RMS (typical). No spoke and engine still quiet (well as quiet as it was when it was new).

As we all know, "quite" is a relative term with Jeep motors.

 

[Red97XJ]

My 99 has 297K, still runs strong. Only leak is the RMS (typical). No spoke and engine still quiet (well as quiet as it was when it was new).

wow, 297k is impressive! Thats the winning high number so far on this thread!

 

[MrClean]

My '97 had 145k when I got rid of it. I looked at a '97 that had 630k on it when I was looking for another one. I doubt it was the original motor.

 

[Red97XJ]

So has anyone with a 97+ hit 300k?

 

[sjx40250]

I don't know of any instances of bad blocks, just the head from 99+ with a casting number of 033xx.
90 XJ with head work and new rings and conrod bearings at 147K. Now at 190K no problems. The cylinder walls still had the xhatching from the original honing. Just broke the glaze prior to putting in cast rings.
92 XJ with 225k and smoking Bought used with 187K
98 XJ with 123K no problem

 

[FlexdXJ]

Lots and lots of 200k 4.0 motors out there. And an amazing amount make it to and past 300k.

Keeping up with fluid changes contributes to longevity as does other common sense basic maintenance.

140k on my 99 daily driver. It runs "as new". :wave:

My 95 has 248k and it smokes a little. I have only put 7 of those miles on it though!

 

[TerraWombat]

The engine is pretty much all the same throughout the years. The '00 and some early '01's had a bad casting, and the block cracks sometimes.

Incorrect - the cylinder heads crack, the blocks do not.

They all last long.

Correct!

BTW, I have an '01 with a '98 motor. The original '01 motor had about 157K on it, but it had a spun rod bearing. I could have had the crank turned and bad rod replaced, but opted for a complete replacement motor instead (was about the same price and I got rid of the suspect 0331 cylinder head). The '98 motor came from a shady junkyard who claimed it had '82K miles on it, but a Carfax revealed last reported mileage was 155K. I've put about 5K miles on it since I installed it and it seems to be running great other than a strange knocking sound that I can't trace down. I suspect it to go a lot further and will drive it till it dies.

Also have a '98 4.0L with 130K that should also go the distance

 

[Red97XJ]

Merry Christmas eve. Anyone else have some high mileage to post?

 

[Wayne Sihler]

My 96 has 306,000.The wifes 98 has 235,000, and my (sons) 87 has 189,000

Wayne

 

[wildcar]

My 99 has just over 120,000 now and runs as good as the day I got it with 30,000.
My wife had a 96 2 door sport that had just over 175,000 when we sold it to a friend, he took it over 200,000. It burned some oil but not to bad, but it still pulled in mid to high 20 mpg's on the highway. I miss that Jeep.