Engine selection for reliability- 3.6/I4turbo/ecodiesel

[cafecito820]

Hey guys.

I’m not new to turning a wrench, but I am new to jeeps. I am considering trading for one. I was hoping to read/discuss about the I4t, 3.6, and ecodiesel. My intended use is fairly low demand. I have a work supplied vehicle so it will be mostly a get-around vehicle and a way to take my kiddo hunting, fishing, hiking, trail riding, etc. I don’t see rotational mass being any larger than 33’s. Most likely would select a rubicon-like setup and keep it stock in the way of performance.

3.6- I’m most drawn to this engine at face value. Seems like every E1 and teen has beat the absolutely crap out of this engine in the challengers and chargers and it generally does pretty good.

I4t- seems like a ton of people are pretty happy with this engine. I just worry about jamming boost into an undersized 4cyl is recipe for longevity issues. I’ve briefly read that chasing oil leaks is not uncommon? I live in a rural area. I do have access to 91 octane. I know boosted engines like higher octane. But I question if the tradeoff is worth it here?

ecodiesel- I like the idea of diesel and the reputation it has for longevity. I do worry about dealing with DEF and a more complex system. Specifically I am worried about repair cost down the road with the engine, though I’m sure they’re doing fine.

Do you guys have any experience or known common issues with these engines. I just hoping to pull from your experience and make an educated decision. Thank you very much for your time.

I'm about the same as you - armchair mechanic, but not a hardcore Jeeper.

My wife and I have been in a 2021 2-door JL Rubicon with the 2.0L Turbo engine for three years now. Prior to that, I owned a 2021 Gladiator Mojave with the 3.6L engine, and it was my daily driver.

Given all that I've seen and done in both engines, I would lean ever so slightly toward the 3.6L. To your point, it's had the crap beaten out of it, and it's a reliable, safe choice. The only issue I ever had with it was low-end torque and getting up hills. However, I was in a Gladiator, which are quite a bit larger and heavier than Wranglers.

If needing low end torque and wanting some pep in your step aren't priorities, get the 3.6L and don't look back. The only time I'd definitely consider the 2.0L Turbo would be if I were a 100% pavement princess driving a 4-door. The pep from the turbo would help get a 4-door moving a bit better in traffic where the 3.6L would probably already feel a bit sluggish (even before you put bigger wheels and tires on).

Sponsored

 

[Kyanche]

The only time an oil change issue comes up is when the engine is full of sludge from blatant neglect. In no other situation is oil change maintenance ever a concern. If you went too long between changes the sludge is obvious.

What's your thoughts on oil change intervals for a vehicle that isn't driven much? I put like 3k miles a year on my jeep.

 

[alphawolff]

What's your thoughts on oil change intervals for a vehicle that isn't driven much? I put like 3k miles a year on my jeep.

I personally do not see the point of oil changes based on time alone. Everytime I've seen low mileage OCIs the oil appears brand new. I believe the worry is due to contaminants building up in the oil as it sits, but in practice I've never seen it first hand. Maybe it's environment dependent? Areas that consistently get below freezing might have water dilution issues from condensation. If the engine oil doesn't get hot enough it won't all burn out. Definitely a concern for those vehicles if it sits a long time and they only do short trips.



If you're doing 3k miles a year just change it once a year. You could do it every 2 years if you want, it isn't a big deal.

 

[jbcrane]

Go with the 3.6 PUG and keep the OCI's @3k . Odds are it'll be great.

 

[Jay_NM]

3.6 is one of the most common engines out there. its in trucks, cars, jeeps, and mini vans. seems to do very well. You will hear more bad than good about all three engines here just because its a forum. People come here to talk about their problem to find a solution. Anyways really depends on where you will be driving at the most. Will you be around town in the city mostly then a naturally asperated motor will suit you fine. will you be at higher altitudes or live some where like Denver Co? then one of the turbo motors would be better as forced induction does better in that type of area. The 3.0D is going to be pricey to fix due to the parts of a diesel engine. The 2.0 runs on 87 OCT recommended by the owners manual. I find that the 3.6 Runs much smoother on 89-91 oct fuel. been running my 3.6 on 91 for the past 5 years with only great results. Down fall is, On 2025 they no longer offer the 3.6 with auto transmission. you would have to find a 24 and older Model year to get the 3.6 with auto trans.

I live at an elevation that’s 1500’ higher than Denver, CO and my 3.6 performance is awesome. No turbo needed, unless going diesel.

 

[Kyanche]

If the engine oil doesn't get hot enough it won't all burn out. Definitely a concern for those vehicles if it sits a long time and they only do short trips.

If you're doing 3k miles a year just change it once a year. You could do it every 2 years if you want, it isn't a big deal.

Thanks! I use mobil1 0w20 and usually after a year it looks fairly dark, and.. trip length? Eh it usually warms up enough but some trips can be fairly short. Sometimes the oil gets to smelling like gas because of that LOL.

I'll consider using 0w30 next time I do an oil change.

(the price difference between mobil1 and pennzoil and costco/walmart brand oil is so small when you change it once a year! The thought crossed my mind of using Liqui Moly LOL)

 

[Overwatch727]

I wanted to thank everyone for your response and input. Seems like the I4 and 3.6 are both pretty solid. Doesn’t seem like there is a major trend one way or the other regarding these two engines, I will probably just not worry about which of the 2 engines it has and go where I find the best balance of a good deal.

On another note, I’m sure this topic has been discussed quite a bit, thank you for the minimal bashing. I’m new here and I don’t have quite the same experience that you do. It’s been both entertaining and useful to read through all of this. I’ll be joining the family in the next month or two.

 

[JLUR Farout]

Hey guys.

I’m not new to turning a wrench, but I am new to jeeps. I am considering trading for one. I was hoping to read/discuss about the I4t, 3.6, and ecodiesel. My intended use is fairly low demand. I have a work supplied vehicle so it will be mostly a get-around vehicle and a way to take my kiddo hunting, fishing, hiking, trail riding, etc. I don’t see rotational mass being any larger than 33’s. Most likely would select a rubicon-like setup and keep it stock in the way of performance.

3.6- I’m most drawn to this engine at face value. Seems like every E1 and teen has beat the absolutely crap out of this engine in the challengers and chargers and it generally does pretty good.

I4t- seems like a ton of people are pretty happy with this engine. I just worry about jamming boost into an undersized 4cyl is recipe for longevity issues. I’ve briefly read that chasing oil leaks is not uncommon? I live in a rural area. I do have access to 91 octane. I know boosted engines like higher octane. But I question if the tradeoff is worth it here?

ecodiesel- I like the idea of diesel and the reputation it has for longevity. I do worry about dealing with DEF and a more complex system. Specifically I am worried about repair cost down the road with the engine, though I’m sure they’re doing fine.

Do you guys have any experience or known common issues with these engines. I just hoping to pull from your experience and make an educated decision. Thank you very much for your time.

I've owned all three. 3.6L for poking on trails and flat ground driving with a small trailer is solid, auto or manual. Ecodiesel is a blast to drive, but it is HEAVY you won't be leaving it stock for long. There are a lot of things to go wrong with it. Only buy if you drive 30+ miles most every time you start it as short trips will gum it up. It will get you the best MPGS but will cost the most with maintenance as you now have to change the fuel filter every oil change. It takes nine quarts of oil too and the filters are not cheap. It is also sensitive to heat and will go into limp mode on an incline three seasons of the year. I now have the 2.0L. It pulls good, moves good, but in my JLR with 35's and 4.56 gears I average 17 MPGs. Works good off-road. Mountain passes are a breeze. It does sound like a Singer sewing machine made love to an old International school bus engine though.

 

[JLUR Farout]

I wanted to thank everyone for your response and input. Seems like the I4 and 3.6 are both pretty solid. Doesn’t seem like there is a major trend one way or the other regarding these two engines, I will probably just not worry about which of the 2 engines it has and go where I find the best balance of a good deal.

On another note, I’m sure this topic has been discussed quite a bit, thank you for the minimal bashing. I’m new here and I don’t have quite the same experience that you do. It’s been both entertaining and useful to read through all of this. I’ll be joining the family in the next month or two.

It might be worth the drive, look up Findlay Jeep in Post Falls, ID. Ask for Jordan. I have bought a LOT of vehicles in my life. He did me right on trade, and on the new one. Small dealer that works with you.

 

[yokramer]

I wanted to thank everyone for your response and input. Seems like the I4 and 3.6 are both pretty solid. Doesn’t seem like there is a major trend one way or the other regarding these two engines, I will probably just not worry about which of the 2 engines it has and go where I find the best balance of a good deal.

On another note, I’m sure this topic has been discussed quite a bit, thank you for the minimal bashing. I’m new here and I don’t have quite the same experience that you do. It’s been both entertaining and useful to read through all of this. I’ll be joining the family in the next month or two.

For SURE go drive them both, never know if one or the other will really grab you or you hate driving one.

 

[jadmt]

It might be worth the drive, look up Findlay Jeep in Post Falls, ID. Ask for Jordan. I have bought a LOT of vehicles in my life. He did me right on trade, and on the new one. Small dealer that works with you.

I tried working with Findlay but they were not close to matching Dave Smith for me. I have tried using findlay 2X and the first time Dennis Dillion gave the best deal and the second time Dave Smith gave the best deal..definitely pays to check several out for sure.

 

[rock123]

I tried working with Findlay but they were not close to matching Dave Smith for me. I have tried using findlay 2X and the first time Dennis Dillion gave the best deal and the second time Dave Smith gave the best deal..definitely pays to check several out for sure.

When I've searched Dave Smith and Dennis Dillon in the last few years, the prices are not even in the ballpark of some parts of the US. I recommend buying from a dealer using Cargurus or something- you will save many thousands. Search from low to high price with your options you want....

 

[dabolay]

Hey guys.

I’m not new to turning a wrench, but I am new to jeeps. I am considering trading for one. I was hoping to read/discuss about the I4t, 3.6, and ecodiesel. My intended use is fairly low demand. I have a work supplied vehicle so it will be mostly a get-around vehicle and a way to take my kiddo hunting, fishing, hiking, trail riding, etc. I don’t see rotational mass being any larger than 33’s. Most likely would select a rubicon-like setup and keep it stock in the way of performance.

3.6- I’m most drawn to this engine at face value. Seems like every E1 and teen has beat the absolutely crap out of this engine in the challengers and chargers and it generally does pretty good.

I4t- seems like a ton of people are pretty happy with this engine. I just worry about jamming boost into an undersized 4cyl is recipe for longevity issues. I’ve briefly read that chasing oil leaks is not uncommon? I live in a rural area. I do have access to 91 octane. I know boosted engines like higher octane. But I question if the tradeoff is worth it here?

ecodiesel- I like the idea of diesel and the reputation it has for longevity. I do worry about dealing with DEF and a more complex system. Specifically I am worried about repair cost down the road with the engine, though I’m sure they’re doing fine.

Do you guys have any experience or known common issues with these engines. I just hoping to pull from your experience and make an educated decision. Thank you very much for your time.

I'm new to the 3.6 but I will share with you my experience and what I have learned this past year.

My previous experience with Jeep was when I was a teenager, many years ago, my father purchased a brand new CJ-5 as his foray into the world of 4WD. I fell in love with that vehicle and was fortunate to put many thousands of miles on it. My father later sold it as he wanted to have larger 4WD vehicles to pull boats, trailers, and so forth.

So my experience with 4WD vehicles followed with lots of vehicles other than Jeep.

Jump forward to 2024. After several years of looking at Jeep models and options I thought I knew what I wanted... but when it got down to buying one I fell in love with a 2 door JL Willys with the 3.6 engine.

I purchased this Jeep, the first one I ever owned, in May 2024. Around 400 to 500 miles I began experiencing check engine lights. Very long story short... and after being towed multiple times, the dealership service department, realizing that I was not trying to declare that I had a lemon because I really did not want to part with my dream Jeep, got Chrysler's STAR Center involved. My Jeep over the course of most of the summer, set in the dealership service department and received an entire new engine, exhaust system, batteries, and electronics. They also gave me a new extended warranty. And, while my Jeep was in process they provided me with a brand new Jeep to drive for how every long it took to get my Jeep repaired and returned to me.

I got to know several of the service technicians there and had the opportunity for them to share their years of experience with me. I made the decision to follow their advice completely.

First... don't modify the engine trying to extract more horespower.
Second... don't hotrod the engine... drive like you want to put million miles on it.
Third... if you pull a trailer, follow the towing guidelines.
Fourth... use the recommended oil weight. Chrysler likes Pennzoil. I use Pennzoil Ultra Platinum 0W-20.
Fifth... change your oil and filter every 3,000 miles. I have been told the same advice by a number of knowledgeable engine techs. It doesn't matter that your oil doesn't lose lubricity in 10,000 or 20,000 or more miles. OIl gets dirty.
Sixth... the 3.6 engine doesn't like to set and idle for long periods of time. Dealer service departments that regularly service public safety vehicles, taxi cabs, and similarly used vehicles know that sitting for long periods of time idling is not a good thing. I was told to use BG MOA at every oil change. It does make a difference.
Seventh... I've added a couple of other options as well. I use BG ERP added to the oil and follow directions before draining.
Eighth... I also add one can of BG 44K Platinum to a full tank of gas at every oil change.

Additional things I do is rotate the tires and do alignment at every oil change.

Those are the things I am doing in addition to following mileage based maintenance as well.

I'll report what happens over time.

And for the record, I don't have any relationship, financial or otherwise, with either Pennzoil or BG products or any automotive dealership.

Hope this helps.

Dennis

 

[jbcrane]

I live at an elevation that’s 1500’ higher than Denver, CO and my 3.6 performance is awesome. No turbo needed, unless going diesel.

Completely agree. A perceived lack of power prob. comes from gears, not horsepower. My 3.6 has plenty of power at (high) elevation (like high in the San Juan's) with 4.88 gears.

 

[Overwatch727]

I'm new to the 3.6 but I will share with you my experience and what I have learned this past year.

My previous experience with Jeep was when I was a teenager, many years ago, my father purchased a brand new CJ-5 as his foray into the world of 4WD. I fell in love with that vehicle and was fortunate to put many thousands of miles on it. My father later sold it as he wanted to have larger 4WD vehicles to pull boats, trailers, and so forth.

So my experience with 4WD vehicles followed with lots of vehicles other than Jeep.

Jump forward to 2024. After several years of looking at Jeep models and options I thought I knew what I wanted... but when it got down to buying one I fell in love with a 2 door JL Willys with the 3.6 engine.

I purchased this Jeep, the first one I ever owned, in May 2024. Around 400 to 500 miles I began experiencing check engine lights. Very long story short... and after being towed multiple times, the dealership service department, realizing that I was not trying to declare that I had a lemon because I really did not want to part with my dream Jeep, got Chrysler's STAR Center involved. My Jeep over the course of most of the summer, set in the dealership service department and received an entire new engine, exhaust system, batteries, and electronics. They also gave me a new extended warranty. And, while my Jeep was in process they provided me with a brand new Jeep to drive for how every long it took to get my Jeep repaired and returned to me.

I got to know several of the service technicians there and had the opportunity for them to share their years of experience with me. I made the decision to follow their advice completely.

First... don't modify the engine trying to extract more horespower.
Second... don't hotrod the engine... drive like you want to put million miles on it.
Third... if you pull a trailer, follow the towing guidelines.
Fourth... use the recommended oil weight. Chrysler likes Pennzoil. I use Pennzoil Ultra Platinum 0W-20.
Fifth... change your oil and filter every 3,000 miles. I have been told the same advice by a number of knowledgeable engine techs. It doesn't matter that your oil doesn't lose lubricity in 10,000 or 20,000 or more miles. OIl gets dirty.
Sixth... the 3.6 engine doesn't like to set and idle for long periods of time. Dealer service departments that regularly service public safety vehicles, taxi cabs, and similarly used vehicles know that sitting for long periods of time idling is not a good thing. I was told to use BG MOA at every oil change. It does make a difference.
Seventh... I've added a couple of other options as well. I use BG ERP added to the oil and follow directions before draining.
Eighth... I also add one can of BG 44K Platinum to a full tank of gas at every oil change.

Additional things I do is rotate the tires and do alignment at every oil change.

Those are the things I am doing in addition to following mileage based maintenance as well.

I'll report what happens over time.

And for the record, I don't have any relationship, financial or otherwise, with either Pennzoil or BG products or any automotive dealership.

Hope this helps.

Dennis

one thing Ive learned over the last few years is pennzoil PUP is a phenomenal oil. Agree with you for engine mods and whatnot. I’m not interested in a jeep for horsepower. Any modifications would likely be cosmetic or functional only. One thing I’m curious about though is an alignment every oil change? To me it seems a bit excessive, what’s your theory on this part? Certainly not a jab, just Wondering if I’m missing something.

Sponsored