Thoughts on 3.6 longevity

[Punknhed]

Watch some of the tear down videos on Youtube of the 3.6L and similar modern engines and you'll marvel at how mechanically complex they are, some of the cost compromises manufacturers make, and how common they fail simply because of poor maintenance. The current production 3.6L has no consistent fail points. The old JK era #2 valve seat issue was finally resolved some years ago and the rocker needle bearing issue was cured as of 2019. Change your oil regularly. Depending upon how much low speed vs highway miles, change at 3,000-5,000 miles. (If the mileage calculator on the dash suggests longer intervals, thank it for the suggestion and ignore.)

3.6L is a great all around engine and perfect for trail Jeeps, particularly matched to the 8 speed. You don't need 400HP to crawl an obstacle at 2MPH.

may not need it but it sure as hell would be nice knowing its their.

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[Punknhed]

this thread sure turned into a shit show quick.....
quite entertaining this early on a saturday morning at work

 

[Willys41]

So then you DON'T believe they aren't all affected? Your wording is confusing.

It does happen at a wide range of miles, and for that reason no one can say at this point that they aren't all affected. Much like the DoD lifters on the Hemi and SBC V8s for example - the old single mode systems would generally fail in the 130-150k range. Some would fail sooner, some would last longer...but it's generally accepted that they all WILL fail, it's just a matter of when. Our JLs are relatively young, the vast majority of us haven't hit 100k miles yet...so there's still a lot of time left before we will know the full extent of this.

That said, the problem is a design issue. The only way to fix it is to fix the design. Different weight oil isn't going to fix it, different oil change intervals isn't going to fix it. If you want to keep your JL for the long haul, get a warranty.

I am not sure what you are saying is true.
The Maserati 3.0 gas is basically the same motor as the Pentastar 3.6.
The Maserati 3.0 uses European 5w40 oil and runs at 195 to 200 degrees coolant temps unlike the 3.6 that uses 0w20 and can run as high as 235+ coolant temps.
The Maserati 3.0 and Pentastar 3.6 use the same valve train and I have not yet found any cam/rocker failure on the Maserati 3.0.
0w20 to 5w30 can have up to 800 ppm ZDDP.
European 5w40 can have up to 1200 ppm ZDDP.
I now run European 5w40 and have installed the RPM Extreme JL fan controller keeping my coolant temps below 200 degrees and only 212 under extreme loads.
Will I avoid the cam and head gasket issues. I don't know. Put common sense would say lower temps and better oil could.

 

[1Warped Jeeper]

i was seriously considering going to a 21 on my Ultra. it had a 16 inch 80 spoke wheel that was really pretty. but then i fucking ran the damn thing off the road a couple months ago...... im still sick over that fuckup.

Oh crap!!! Glad you're okay. I really think the 21" looks good, but in riding, the 19" appears to be the sweet spot. Get the bike fixed yet?

 

[Punknhed]

Oh crap!!! Glad you're okay. I really think the 21" looks good, but in riding, the 19" appears to be the sweet spot. Get the bike fixed yet?

sadly was totaled.

 

[1Warped Jeeper]

sadly was totaled.

Sorry to hear. But it opens up a lot of possibilities for a replacement. (Go Road Glide! You won't regret it!) I bet there is some good options price wise either new or used. Like Jeep, sales are down.

 

[Punknhed]

Sorry to hear. But it opens up a lot of possibilities for a replacement. (Go Road Glide! You won't regret it!) I bet there is some good options price wise either new or used. Like Jeep, sales are down.

dispise the road glide lol.

 

[Swisskidd]

I am not sure what you are saying is true.
The Maserati 3.0 gas is basically the same motor as the Pentastar 3.6.
The Maserati 3.0 uses European 5w40 oil and runs at 195 to 200 degrees coolant temps unlike the 3.6 that uses 0w20 and can run as high as 235+ coolant temps.
The Maserati 3.0 and Pentastar 3.6 use the same valve train and I have not yet found any cam/rocker failure on the Maserati 3.0.
0w20 to 5w30 can have up to 800 ppm ZDDP.
European 5w40 can have up to 1200 ppm ZDDP.
I now run European 5w40 and have installed the RPM Extreme JL fan controller keeping my coolant temps below 200 degrees and only 212 under extreme loads.
Will I avoid the cam and head gasket issues. I don't know. Put common sense would say lower temps and better oil could.

Completely agree with your stated observations here! Two points of note in regards to the Maserati engine version:

Reportedly, the cylinder walls are thicker (likely due to smaller bores), and the oil gallery bores are larger to offer better cooling and better oil flow at higher RPM.

I’m running 5W30 M1 in all 3 of our 3.6’s. Over 250k combined miles driven. Two owned since new. 5k miles OCI.

I believe the valve train issues are a combination of influences. Marginal parts design with variances in quality (by themselves all within design spec).
Individual driving conditions (short trips, barely reaching oil operating temp, or prolonged idling), vs highway and interstate driving (oil at operating temp and ample flow/splash on valve train). Lastly maintenance frequency, where everyone has their preferences.

 

[jeepingib]

I have been doing the off road thing for a lot of years. I am done with that

And you bought a Wrangler?!?! Have you considered that you may have purchased the wrong vehicle?

 

[Willys41]

Completely agree with your stated observations here! Two points of note in regards to the Maserati engine version:

Reportedly, the cylinder walls are thicker (likely due to smaller bores), and the oil gallery bores are larger to offer better cooling and better oil flow at higher RPM.

I’m running 5W30 M1 in all 3 of our 3.6’s. Over 250k combined miles driven. Two owned since new. 5k miles OCI.

I believe the valve train issues are a combination of influences. Marginal parts design with variances in quality (by themselves all within design spec).
Individual driving conditions (short trips, barely reaching oil operating temp, or prolonged idling), vs highway and interstate driving (oil at operating temp and ample flow/splash on valve train). Lastly maintenance frequency, where everyone has their preferences.

I can only hope I am on the right track to keep both my Wranglers running for a very long time.
I have never herd of a truck running at 235+ degrees like the Wranglers. The Rad. fan only comes on at 75% fan speed at 231 degrees.To little to late. The fan controller solved that problem.
My 2020 F250 only hits 212 on a steep long hill pulling my goose neck trailer with my Willys on it.

 

[2nd 392]

You drive a Harley? That could explain the confusion over trying to put something other than 20" tires on a 20" wheel.

You called Nitto to confirm. That's fucking hilarious. Hopefully you realize you're infamous there now.

Well that does kinda explain his confusion. 21” is a common size, never seen a 20”. So if he had a 20” wheel he was likely trying to put 21” tires on it.

 

[2nd 392]

may not need it but it sure as hell would be nice knowing its their.

Hell yea, I assure you the approaching 400 HP Chevy in my 63 beat the crap out of the 72 HP Hurricane it replaced. And yes, even crawling, it could idle over nearly anything….. Driving it towing a trailer with gear and supplies for a week over Donner Summit 65 MPH beat the crap out of having to tow it too……
I really don’t get the reason some disparage power, gears can only do so much.

 

[2nd 392]

i was seriously considering going to a 21 on my Ultra. it had a 16 inch 80 spoke wheel that was really pretty. but then i fucking ran the damn thing off the road a couple months ago...... im still sick over that fuckup.

You are the one throwing your leg over it, but IMO a 21 on an Ultra would look unbalanced ….. I am a bit OCD about “balance” though.

 

[Swisskidd]

I can only hope I am on the right track to keep both my Wranglers running for a very long time.
I have never herd of a truck running at 235+ degrees like the Wranglers. The Rad. fan only comes on at 75% fan speed at 231 degrees.To little to late. The fan controller solved that problem.
My 2020 F250 only hits 212 on a steep long hill pulling my goose neck trailer with my Willys on it.

I live in SW FLA, flat as a pancake. After reading some of your other posts, I started to pay closer attention to the temps. Oil and water remain consistently between 190 and 205 degrees (Ambient upper 90’s). AC on all the time (cooling fan engaged).
One time during the ‘Winter’ (60’s outside), I drove without AC and while sitting in line, I watched the temp creep up to 228. Way beyond my comfort zone. So I’m making it a habit to keep the AC on all the time.

 

[Punknhed]

You are the one throwing your leg over in, but IMO a 21 on an Ultra would look unbalanced ….. I am a bit OCD about “balance” though.

the way i was going to do mine it would have looked good. the plan was to change the front fender also go to one that fits that wheel/tire combo instead of leaving the stock fender.
but, i dont have to worry about it because i wrecked it and its gone. soooooo for now, focus on the jeep.

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