I have a 2008 JKX 4dr. 28,000 original miles. Have heard the horror stories about this power plant once you start reaching higher miles. Wanting to do some performance upgrades but don't want to induce problems prematurely.
What minor improvements can I do without causing issues and are there any preventative maint. upgrades that I can do to prevent the major issues down the road?

 

Best upgrade possible would be to set it up for marine use.

Pull it out, tie a rope to it and drop it in your favorite spot in the lake and use it for an anchor.

Then install an LS in the hole where the 3.8 once sat. Other than that, it's like beefing up a D30 front axle. Run it until it breaks and then upgrade.

 

I think a majority of people have over 100k+ miles on the 3.8 with little to no issues. Just keep a close eye on your oil level. Running it dry because your not paying attention to the oil it's burning is a common issue.

 

Other then lack of power with big tires and drinking coil what issues are you talking about? I think the 3.6 has had more issues then the 3.8.

 

^agree'd, when I was looking to buy, the general consensus was that the 3.8 was proven to go high mileage in both the jeep and minivan world, albeit a bit lacking in the power department, and the 3.6 was relatively new, unknown regarding longevity, yet had it's known (head) issues.

Not sure what is done to your jeep, but typically re-gearing will give you the most bang for your buck.

 

28K miles on a 2008? What did someone park it in their garage and forget about it?

I agree with everyone else, I haven't heard any horror stories in regards to the 3.8L. It's a tried and true proven carry-over minivan engine. I've got 126K miles on my 3.8L. Others have reported over 200K.

Now the 3.6L is peppier and initially had some head related issues and hasn't been proven out as much as the 3.8L, so that's another story.

 

Gears

 

What I would tell you from a couple of threads i read about low mileage. Drive it more. Both of them had engines replaced before 100,000; because it sat for days. I mean one said he might not drive it for two weeks. The shop said the demise was all the oil drained and too many dry starts wore the parts. Just my $0.02

 

2010 JKR 3.8 was replaced at 90,000 miles under warranty. Dealership F'd up the bearings and threw a rod apparently. So this does not go to the score of another 3.8 blowing up due to low oil.
Currently at 140k miles now with the second factory 3.8 motor (50k miles on the second motor)

Jeep is being transition from a daily to a full time toy, and will be looking into the hemi plug-n-play kit.

Only upgrade with 3.8 motor is intake and cat back exhaust.

 

Wait so the dealer did work and then it exploded? Or it exploded and the dealer messed again during repair?