Thoughts on high mileage?

Will’s TJ

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Nov 23, 2019
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ATL Georgia
My TJ has 167K miles and I'd like to keep it through college, so the next 5 or 6 years. If I do regular maintenance, will it last? Based on what I've read, the 4.0L can last to 300K, but to be honest I think I'd feel better if I bought one with around 100K miles. Thoughts?

Also - I know lots of people on here have jeeps with lower mileage, where should I look if I were to by one?
 
Well, you're wrong about 300k.

Assuming you regularly maintain it, it can last well over 600k, as there was a guy here on the forum who had a TJ 4.0 with over 600k miles when he sold it.

The key through is proper maintenance. This means servicing the cooling system, O2 sensors, changing fluids, gaskets and seals when they go bad, etc.

The only thing you'll need to keep in mind is that the transmissions generally need a rebuild around 200k miles or so (the guy with 600k on his said he had to have the transmission rebuilt at 200k, 400k, and 600k roughly), as that's normal.

If you look on this forum, there are plenty with low mileage.

See here: https://wranglertjforum.com/forums/jeeps-for-sale.30/

You should also check Craigslist, Facebook Marketplace, etc.

There are TONS of low mileage TJs out there, tons of them!
 
Have you had any reasons to not trust it yet? I have a low mileage and have chased a problem on and off over 2 years, so low mileage is not magic.
 
Assuming you regularly maintain it, it can last well over 600k, as there was a guy here on the forum who had a TJ 4.0 with over 600k miles when he sold it.

The key through is proper maintenance. This means servicing the cooling system, O2 sensors, changing fluids, gaskets and seals when they go bad, etc.

That's crazy! I'm surprised someone bought it, although I suppose its practically a brand new engine at that point. I understand the maintenance aspect, and I think it's more of a mental barrier, because normally I wouldn't want to look down at 300 or 400K on the odometer.
 
That's crazy! I'm surprised someone bought it, although I suppose its practically a brand new engine at that point. I understand the maintenance aspect, and I think it's more of a mental barrier, because normally I wouldn't want to look down at 300 or 400K on the odometer.

Believe me, it is indeed a mental barrier!

A replacement 4.0 can be had for around $2000 or less, so that just goes to show you how cheap a brand new engine is for these things. Even then though, they really do last forever if properly maintained.
 
That's crazy! I'm surprised someone bought it, although I suppose its practically a brand new engine at that point. I understand the maintenance aspect, and I think it's more of a mental barrier, because normally I wouldn't want to look down at 300 or 400K on the odometer.

Canadian odometers are in metric so we get to do that much sooner. It's great! 😊
 
Stuff will start going at some point. Just how it goes with higher mileage vehicles. TJ’s are easy to work on so it isn’t that much of a problem. I wouldn’t sell a TJ that works currently and risk getting into more problems with another one. If it becomes a money pit, get rid of it. If it isn’t, I’d keep it for now.

600k on a 4.0 is still asking a lot. How long they last is very dependent on use and maintenance. I’d expect to get 250k-300k out of a well maintained 4.0. Plenty of people have them blow at 175k if they were beat on and poorly maintained.
 
Sitting here with 260,000, wouldn’t hesitate to drive it cross country tmr. I’ve had to do a few maintaance items that the p.o. Couldn’t be bothered (cooling system, 02’s and my trans is a little crunchy) but she’s a solid Jeep.
 
Sitting here with 260,000, wouldn’t hesitate to drive it cross country tmr. I’ve had to do a few maintaance items that the p.o. Couldn’t be bothered (cooling system, 02’s and my trans is a little crunchy) but she’s a solid Jeep.
Thinking about it, my family owns 6 cars and not a 1 of them is under 100k most are much much closer to 200k, though my tj has the most out of all of them.
 
I've had two 4.0l engines go over 300k, before I sold them. Both of them had over 200k on them when I bought them. A key to keeping these engines going is changing the oil regularly, keeping them cool, and making sure the oiling system is in good working order. I tend to be somewhat obsessed with maintenance, so any 4.0L I've owned, with your kind of mileage, gets an entire new cooling system, a new Melling (standard) oil pump, along with a new oil pick up tube. I also pull the valve cover and replace the valve cover gasket at the same time.

FWIW, pulling the oil pan, to do the oil pump, and valve cover isn't that difficult of a job. The hardest part is dropping the exhaust, so you can remove the pan. Removing the oil pan and valve cover will let you see if there's any sludge in either. If not, that is a big plus. The oil pump is one item that tends to get over looked. Every Jeep I've installed a new one in has seen a significant improvement in oil pressure, especially at idle.
 
At 191k on my TJ. Just put 950mi on it last week and the motor was never the concern. I change the oil every 3k miles with conventional 10w30. Only “issues” I have are a cracked exhaust manifold and a slight drip from the rear main seal. So, $100 worth of parts maybe?
 
My TJ has 167K miles and I'd like to keep it through college, so the next 5 or 6 years. If I do regular maintenance, will it last? Based on what I've read, the 4.0L can last to 300K, but to be honest I think I'd feel better if I bought one with around 100K miles. Thoughts?

Also - I know lots of people on here have jeeps with lower mileage, where should I look if I were to by one?
My 2003 Sahara 4.0L auto trans is now at 339,000 mile mark.

The only aftermarket is a set of 31" tires, the brake assemblies, the battery, exhaust pipe, radiator, u-joints, ball joints and the water pump assembly.

The mechanical parts did not fail, I replaced them just for preventive measures. Straight six engine is OEM.
 
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Mine has 227k, runs like a champ other than valve train ticking when cold, could be a valve sticking but other than that, runs great.
 
I always find it funny when people say "this motor is bulletproof when you take care of it". Well no shit, so is every other motor.

I say keep what you have, especially if its paid off. When you get to college you're not going to be driving around as much as you think. Around town, sure. Home for the holidays. Maybe save a little for those random repairs that come up.
 
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I always find it funny when people say "this motor is bulletproof when you take care of it". Well no shit, so is every other motor.

I say keep what you have, especially if its paid off. When you get to college you're not going to be driving around as much as you think. Around town, sure. Home for the holidays. Maybe save a little for those random repairs that come up.
Good post.

A jeep is an awesome college vehicle.

I've seen (and owned) a TJ with 22,000 miles that needed thousands of dollars to make it drivable.

Mileage/condition depends on how it was treated and maintained.

Today's engines last ...it's the peripheral components that can drive you nuts.
 
My 2003 Sahara 4.0L auto trans is now at 339,000 mile mark.

The only aftermarket is a set of 31" tires, the brake assemblies, the battery, exhaust pipe, radiator, u-joints, ball joints and the water pump assembly.

The mechanical parts did not fail, I replaced them just for preventive measures. Straight six engine is OEM.
Is your transmission itself at 339k or did I misread?
 
FWIW, I have 187k on the clock and my engine runs great. I did have to run some BG treatment through it to treat some carbon after purchasing it due to a tick but that helped tremendously.
 
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I can also add to this. Currently at 261,000 and going strong with no plans of slowing down. I have the original motor and trans, no rebuild or issues. Regular maintenance and a sweet tone when you talk to it and these things last forever.

I am in the process of replacing all wear items as they are mostly original. I have had the thing since 174,000 and was a broke college student who could only due regular maintenance (oil, brakes, a thermostat here or there and a sensor when they went bad) and now that I am pretty stable in life I can finally take care of this. I have seen XJ's go for 300-400k on a single motor.

Mileage is just a number and if the Jeep is well taken care of, it really doesnt mean anything.