Who has the highest Miles on an OEM 4.0L...no head/cylinder work.

[Rob Mayercik]

1992 4.0 HO, 207,000 and change, and still climbing in a leisurely fashion (not the DD anymore, though it makes an occasional run to keep its "highway legs" in shape). Who says the Chrysler electronics can't hack it in the "second century club"?

I did have the rod and main bearings changed out at 170K, but it still runs like the day I bought it.

5-90, you said that the nickel content of the blocks went down somewhere in the 91-94 timeframe - I wonder if there's any way to tell by block serial numbers which side of that change?

Rob

 

[BPB]

My neighbor (89) and I (90) are both just below the 200,000 mark, we are racing to see who can get there first.

 

[My_Little_Pony]

My Jeep is still a Fetus compared to most of you....it's at the 229k mile mark.

 

[dusterboy71]

My '88 XJ limited has only 125,000 on it and I brought it back from Vegas to Indiana with no rust! I've put 45,000 on it with no problems except valve cover gasket. My buddies '90 XJ has 367,000 with no major engine work but it's starting to get weak.

 

[yuppiexj]

yuppiexj: I find it funny that you would pick that one example. Is overheating what kills most of the newer motors? I have a 1998 with just over 80k on it and the water pump went out. When I was replacing it I found about an inch of brown sludge in the block. Kind of like baby poop with a little more grit thown in. It didn't smell or taste like baby poop though? At any rate It took me a good while to flush it all out. Now it is much slower to warm and runs cooler. Imagine that.

I like the baby poop example. When I changed the T'stat the coolant was green and pretty, the contents of the radiator and expansion bottle look like muddy water. makes me think they're not playing nicely. 200k original water pump, radiator, probably original coolant too (less spillage).

I had an 88 limited with 164k. it would blow hoses about once a month, I baked that thing 300 degrees plus plenty of times...never had a problem. (I did change the oil right after each baking.). With the 94 I am scared to push it hard at all. It rattles and pings if it gets over 200 degrees.

My water pump on the 88 with 202k has been leaking for some time...it's not wobbling yet. I carry the new one in the back in a box with 2 gallons of water, RTV, and tools. That way I'll never need to actually change it. I thin I finally got that murphy figured out

 

[jkkj]

This getting a little off topic, but mine runs at 210 all the time. I was going to put a lower thermostat in it when I changed my pump, but was afraid the gas millage would suffer.

 

[BrettM]

my '88 runs at 210 in -5 degrees and at 105 degrees...

 

[red91]

my 91 just turned 100k, only light lifter niose. I'm doing the turtle thing. I'll catch up with the rest of you HOPEFULLY! (knock on laminated pressboard)

 

[Trail-XJ]

175,000 with some noises but still goes down the street!

 

[5-90]

1992 4.0 HO, 207,000 and change, and still climbing in a leisurely fashion (not the DD anymore, though it makes an occasional run to keep its "highway legs" in shape). Who says the Chrysler electronics can't hack it in the "second century club"?

I did have the rod and main bearings changed out at 170K, but it still runs like the day I bought it.

5-90, you said that the nickel content of the blocks went down somewhere in the 91-94 timeframe - I wonder if there's any way to tell by block serial numbers which side of that change?

Rob

ChryCo electronics - I probably said it, but I'm biased toward Bendix. Call your good fortune a fluke (or perhaps ChryCo finally got sorted...)

Finding out exactly when would take more digging that I have time for at the moment, but I think it actually dropped when everything went to ChryCo spec for the 1991MY. The harder block material would also have made the knock sensor compensation more effective, by transmitting lighter knocks and correcting them before they became problematic. I do recall finding that the AMC-spec blocks (which were used, I believe, until late 1989 to mid 1990 MY) were the high-nickel alloy like the old Hemi engines. Eagle - have you anything to add on this?

5-90

 

[XTrmXJ]

so why do the newer engines only seem to last 100K at hest? It can't be only because of less nickel content.

my 98 has about 134,000mi on it and I have 35s.. The eng is still running as strong as it did the day I bought it.. If I give it to much gas from a dead start it will go side ways and I only have 4.56 gears ..

 

[XTrmXJ]

My 89 MJ is running at 226,000 and still strong at the engine.. The only thing ever changed was the water pump, the oils, and a clutch..

 

[Rob Mayercik]

ChryCo electronics - I probably said it, but I'm biased toward Bendix. Call your good fortune a fluke (or perhaps ChryCo finally got sorted...)

Finding out exactly when would take more digging that I have time for at the moment, but I think it actually dropped when everything went to ChryCo spec for the 1991MY. The harder block material would also have made the knock sensor compensation more effective, by transmitting lighter knocks and correcting them before they became problematic. I do recall finding that the AMC-spec blocks (which were used, I believe, until late 1989 to mid 1990 MY) were the high-nickel alloy like the old Hemi engines. Eagle - have you anything to add on this?

5-90

No need to break out the shovels - if you don't happen to know off the top of your head, don't sweat it. You make an interesting point about the correlation of block hardness to knock detection also. I wonder if unnoticed knocking in newer engines is a contributing factor in some new engines not lasting as long as their predecessors...

Anyhoo... fluke or not, I'll take my 207K and raise you whatever I can spin it to. I suspect that part of my good fortune comes from nearly 4 years of 30k/year highway DD duty, with oil changes every 6K and Tranny/tcase/diffs every 12mo/30K. I take care of my vehicles, and I'm not afraid to shell out a few extra bucks to do a job right the first time so it'll last longer. I guess it shows in how long they last. (which is good, since I subscribe to my father's "drive 'em til just the wheels fall off, and then trade it on a new one" philosophy. (of course, with the XJ, that'll mean it's time for new wheels )

Rob

 

[markpr]

Mines a '95 4.0L stick @ 150K miles and pulling stronger now than it did at 75K miles.

Switched to Synthetic at 140K without a problem and believe in regularly redlining up through the gears. Aside from normal maintenance items, only problem has been a water pump seal.

Mark

 

[Georgia Jeep]

My buddy bought my mom's 91 Jeep XJ about 8 years ago.She bought it when it had about 10,000 miles then sold it to him at about 100,000 now it has 320,000 he has replaced the water pump, coil and power steering pump X2 other than that just oil every 3500 thats it.Just rattles a little around the torque converter flywheel area. It runs better than my 89 XJ with 180,000.

 

[yuppiexj]

How long do you guys think the KJ 3.7L V6 will last?

My 88 has 202k and my 94 has 174k

 

[EMTJeepers]

160k on my 99?

 

[Jay Welch]

Well then why the heck am I hanging onto this spare 1988 engine?? :dunno:

Someone interested in building a stroker come buy this engine and get it out of my loft!!! :clap:

'89 barely broken in at 165K miles.
Jay in MA

 

[gptherezonlyone]

97 with 249,000 on it. Piston slap since 50k not worried........... Stroker by 300k :repair:

 

[yardape]

1994,..... 137,000 original miles.