I have an '08 with 124k on the clock. My 3.8 uses about a half quart per 1000 miles, which isn't bad in my opinion.

 

2010
150,000 miles
Add a quart maybe every 3 or 4 fill up.
My plan is to change viscosity... but if that doesn't help, I'm not that worried about adding oil.

My Jeep runs fine
Not spending the $$$ on an engine change.
At least not at this time.

 

My 2008 JK has 104,000 miles now and has been consuming oil to the point where I was adding at least a half quart per month. I took it in to the Jeep dealer and they replaced the lower intake gasket. It's been several months now since the repair and I'm no longer losing oil!!

 

167,000 miles on my '07 3.8. I have had oil burning at times. In the past was from a poorly seated PCV valve. More recently I think I was losing oil from a leaking valve cover gasket. I'm currently keeping an eye on it now after having replaced the gasket. Still runs great though.

 

Bought my 08 new in 07. Throughout the years I have had the leaky engine block heater replaced, catylictic converter, 2 rear main seals, front oil seal and harmonic balancer. I threw on a set of plugs at 150k just because. Just turned over 180k and still running like a champ. New exhaust manifold due to arrive tomorrow that will take care of the tick she has before it warms up. Planning to get the overhaul kit just to have on the shelf for just in case. Not burning any oil 👍

 

Reviving this thread, mine is at roughly 180k (switched tires at 40k), original owner. Basically, only changed oil and basic fluids the whole time. It leaks from the main seal which is to be expected, I check oil every month or so, pretty much have stuck with 5w-20 Mobil 1 High Mileage the last few years. Catalyic converter is probably on it's way out.

Just trying to judge how long I have until I have bigger issues, I pretty much only drive it locally, but would like to be able to take it on longer surf trips to OBX/Florida (300 miles either way).

 

Check to make sure it isn't your oil pan seal that's leaking. It can mimic the rear main, as it drips down from the bottom of the transmission housing. I thought mine had been leaking, and was planning to change it out whenever I replaced my clutch a couple of summers ago. Once we had the transmission pulled, you could clearly see that the rear main seal was not the culprit. They aren't really known for leaks on the 3.8. I was at 115k miles at the time.

 

Heck, I had a bit more mileage than that when I headed out on a nearly 10,000 mile adventure into the Arctic Circle with mine. I just passed 276,000 miles running the Colorado Backcountry Discovery Route last week. It does burn a little oil now--about a quart every thousand miles. I did replace the cats--those roads in Canada and Alaska beat the heck out of them and the muffler. I also did have to replace the intake manifold gasket, which is a common 3.8L problem. And the fuel injectors started getting a bit noisy about 225,000 miles, so replaced those. But, it's done well for me. I even made a video about mine when I crossed a quarter million miles a couple years back (haven't added too much both because of the pandemic limiting my adventures, and because I now also own a Gladiator) ...

 

Wow, Mark, 276k is great! I just turned 156k on mine and had to replace both cats. Other than that, I've replaced the upper oil pan gasket, water pump, radiator, and coil pack. Burns oil sometimes but still runs like new. I've put new bumpers and winch on it and had an upholstery shop fix a seat tear. The old Jeep looks almost looks as new as it runs!