We all know the 4.0 inline 6 was one of those motors that would last FOREVER and a day.

I was wondering what kind of mileage everyone is getting out of there 3.8 V6 so far and how many miles do you think we can expect out of our JK's?

I have the 6 spd tranny and I absolutely love my jeep and wouldnt trade it for anything in the world - I sure do hope she lasts till im ....well I hope she out lasts me so I can pass her on to my grandkids lol

 

I get about 20mpg. I belive the 3.8 will last me 300,000 miles min. The body may not but the engine will. This is my daily driver/off road machine. Normal street driving and no dukes of hazard off roading. More like a low speed thrill ride. I like you love my jeep

 

Good point about the body... the metal is awfully thin, and the quality of the factory paint job is suspect at best (just look around your hinges after a few months for the telltale surface rust). I expect at least 200K from my engine, but hopefully much more! I'm hoping that my engine lasts at least as long as they continue to make gasoline!

 

to bad the exhaust, undercarridge, and possibly electronics may be gone by then

 

this 3.8 has been around for a while, not in exactly the way it is today, but the basics of it have been in the chrysler line of minivan for a while now... i worked at an oil change shop that my buddy owned a few years ago when he was short on help and let me tell you, the chrysler minivans with the 3.3 and 3.8 liter engines weren't uncommon to be seen with over 200,000 miles on them. the 3.8 is basically an overbored 3.3... i think these engines will last quite a while to be honest. The electrics that control them are more advanced that they were in those minivans i saw and with the electronic throttle keeping the engine from spooling up right off idle, it might help add some life as well... these are cast iron block motors with pushrods... so were the 4.0 motors... granted they're still two different animals, but you get the point, they're both from the same era. I personally kinda hoped i'd blow mine up around 100k so i'd have reason to swap in a hemi... but realistically, i'm just going to drive it however i feel like driving it and when the motor goes it goes... as long as it last 100k which i'm sure it will.

 

300,000 miles is a tall order for an engine with a cast iron block with aluminum heads. Sorry, but it just is. I still see Toyotas getting head gaskets both out of and in warranty. It's just a fact. If you gotta iron block and aluminum heads, a blown head gasket IS in your future somewhere.

 

Depends on how long Jeep dealerships are around... I have the lifetime powertrain warranty. I guess they could keep it alive to 200k before they have to rebuild it.

 

Personally, I consider the 3.8 to be a piece of junk. Especially compaired to an inline 6. It has no balance shafts to its a rough running engine, it severley lacks low end torque, it has a cast iron block with aluminum heads (great for blowing head gaskets), and compared to the V6's that Ford and GM have, its very poor when it comes to fuel usage. I would greatly prefer to have Fords 3.5L direct injected V6. 60 more hp, 50 lb ft more torque, and far better fuel economy.

However, with that said, I see no real reason the engine should not last 180-200k miles. The rest of the drive train easily should, with the exception of front wheel bearings (unitized junk), and the auto trans/clutch. But as others mentioned, the body may be a bit worse for wear by that time

 

Must be somethin wrong with yours. Mine is one of the smoothest running V6s I've ever seen. Granted, it ain't a powerhouse, but I'm happy with mine.

 

Rough running engine? When I look under the hood while it is idling, I am amazed how smooth and quiet it is. On the road, I see not a hint that it is a rough engine. Is yours rough running?

I did a search for the Ford engine you mention. The one that is 60 more hp is not direct injection. Can you post a link to it? I am interested in reading about it.