Ok here is my deal i currently own a 2011 2 door jk with 3.73 gears. Im frustrated with the 3.8 because it been giving me start up knock since the day i bought it and ive tried almost every oil and filter combo out there. I thought i had the problem fixed with royal purple and a motorcraft filter I let it sit for 3 days and started it and it started really smooth no knock at all. I went outside today after only sitting 1 day and had chatter on startup. I want a solid engine in my jeep i only owe $9000 on my 2011 the only mod ive done to it so far is a arb compressor and tire inflation kit, but this is all about to change i currently have a PR 44 with arb 5.13s chromoly shafts, Coast F/R 1310 shafts, Rockkrawler 3.5in x factor kit with drag link flip and HD tie rod, Detroit 5.13s chromoly shafts for the rear 44, 37in toyos, crager soft 8s and countless little items that im leaving out. None of these items are installed yet but will be as soon as the holidays are over. Here is my concern which engine would be better to build off of i want this jeep to last me a long time because as you can see im about to sink some serious money into it. I dont have any complaints with the 3.8 other than the chatter at startup and that really bothers me im a engine nut. So what do you guys think?

 

I'd say get the 3.6 but mine isn't exactly quiet. There is quite a bit of valvetrain noise in the 3.6 but it doesn't knock like the 3.8. I know because our '06 Grand Caravan has the 3.8. If you do decide to get the 3.6, you'll not want to install the 5.13s you have because they are way too steep for the new Auto.

 

3.6 will come with the 5 speed transmission,

 

Ok, i think I'm about to state the obvious... Everybody complains about the startup knock.. I've yet to see a mass engine failure caused by said startup knock. Look at the 4.0 SOHC in rangers and explorers, I could hear when my neighbor started his up while in my house (70 yards away), but he has always done his maintenance and it has 280,000mi or so on it. I know apples to oranges but I doubt it'll ever be a problem, and if it ever did become a problem what better a time to do a hemi conversion? I'm not saying don't go buy a new jeep, but why dump all the extra money into one that you're going to void the bulk of the warranty with bolt-ons soon? Either way it's a personal decision, enjoy whichever you build and have fun with it.

 

This is a trick question,right?

 

C. Hemi......

 

D. LS1......

 

X2. or diesel.

 

I think it's going to be a while before we see a lot of aftermarket support for the Pentastar. But in the long long long run, it may be a better platform. I'm sure we are going to see horror stories from the 3.6 just like we did with the 3.8, but no engine is perfect.

 

I'd vote for the 3.6. More power, flatter torque curve, and 5 speed auto with a lower first gear. Your 5.13 gears might be a little low for a 3.6 though. Most people are running 4.88 gears with 37" tires, but the 5.13's would still work.