Has anyone heard of the 3.6 cracking heads?

[SteveInOrlando]

Just curious! Looking at videos on you tube and heard a mechanic go on about heads cracking on dodge/Jeep 3.6 Pentastar engines. I haven’t seen that complaint here. Has anyone else heard of cracked heads as a problem for these engines?

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[ShadowsPapa]

Nope. Maybe they are referring to the very early 3.6 heads.
I've bot seen and complaints here or in other Jeep forums.

Be VERY careful of so much of the BS you see on youtube. Sometimes people go nutsy over something that isn't a big deal but they make it one for clicks.
Also check for the year of the video, the year of the engines he's griping about and some real solid information.

 

[ShadowsPapa]

Here ya go - gen 1, early engines. Long long ago, issue long since resolved years ago.


The cracked left-cylinder head issue potentially affects about 0.5-percent of vehicles equipped with the 3.6-liter V-6.
roughly 7500 engines built as the Pentastar V-6 was first coming out in 2012, were found to be susceptible to left-cylinder head cracks, A design modification in late 2012 has reportedly fixed the issue in newer vehicles.

the article is from:
Jun 16, 2014

So it's from engines built a decade ago.

That guy should edit his video or pull it down.

 

[Barnaby’sdad]

Here ya go - gen 1, early engines. Long long ago, issue long since resolved years ago.


The cracked left-cylinder head issue potentially affects about 0.5-percent of vehicles equipped with the 3.6-liter V-6.
roughly 7500 engines built as the Pentastar V-6 was first coming out in 2012, were found to be susceptible to left-cylinder head cracks, A design modification in late 2012 has reportedly fixed the issue in newer vehicles.

the article is from:
Jun 16, 2014

So it's from engines built a decade ago.

That guy should edit his video or pull it down.

Yup. Good find. 0.5% of 7,500 vehicles. That’s 37 engines.

 

[ShadowsPapa]

roughly 7500 engines built as the Pentastar V-6 was first coming out in 2012, were found to be susceptible to left-cylinder head cracks,

Yup. Good find. 0.5% of 7,500 vehicles. That’s 37 engines.

7500 isn't the TOTAL, it's the few found to be susceptible to the crack. Many thousands more were made. So it's 0.5% of the total and of that total 7500 were susceptible but of those not all got the crack.
We don't know how many had been made by the time that the subset of 7500 were found to be susceptible - could be 70,000 had been made by that time.

 

[Barnaby’sdad]

7500 isn't the TOTAL, it's the few found to be susceptible to the crack. Many thousands more were made. So it's 0.5% of the total and of that total 7500 were susceptible but of those not all got the crack.
We don't know how many had been made by the time that the subset of 7500 were found to be susceptible - could be 70,000 had been made by that time.

Ok, so ~370 vehicles.

Going to go out on a limb and guess that the number of 3.0 Eco-Diesel fuel systems that have FOD’d out exceed that number.

 

[Deton8]

July 12, 2024.

2020 Jeep Gladiator sport... 36,450 Miles. Suddenly developed rough idle last week after 2-hr / Hwy speed travel. A couple days later the Stop/Start Service warning illuminated on dash. Rough idle seemed to occur mostly on startup, both cold and warm engine.
With a day or two the Stop/Start Service AND Engine light illuminated. Never use Start/Stop. Turned off on console AND bypassed with Tazer JL.

Troubleshooting....Bypassed auxiliary battery and continued to receive Start/Stop Service warning AND engine light. Diagnostic code indicated misfire on cylinder one. Took to dealership at the beginning of this week.

Result.... Cracked head. Left/front near cylinder one. Outside of 36K warranty but still covered under powertrain warranty. Service advisor said there have been other 3.6L Pentastar with this problem. Didn't say how many....

Btw,.... Same vehicle needed rear axle replaced at 9K mile due to rear diff being bad from the factory. Hmmmm???

 

[ShadowsPapa]

July 12, 2024.

2020 Jeep Gladiator sport... 36,450 Miles. Suddenly developed rough idle last week after 2-hr / Hwy speed travel. A couple days later the Stop/Start Service warning illuminated on dash. Rough idle seemed to occur mostly on startup, both cold and warm engine.
With a day or two the Stop/Start Service AND Engine light illuminated. Never use Start/Stop. Turned off on console AND bypassed with Tazer JL.

Troubleshooting....Bypassed auxiliary battery and continued to receive Start/Stop Service warning AND engine light. Diagnostic code indicated misfire on cylinder one. Took to dealership at the beginning of this week.

Result.... Cracked head. Left/front near cylinder one. Outside of 36K warranty but still covered under powertrain warranty. Service advisor said there have been other 3.6L Pentastar with this problem. Didn't say how many....

Btw,.... Same vehicle needed rear axle replaced at 9K mile due to rear diff being bad from the factory. Hmmmm???

So people don't get the wrong idea that shutting off ess means no ESS issues or errors -
It absolutely doesn't matter a lick that you never used ESS. It's still there, still active, just being told not to shut down as if you pressed the button. That's all tazer does - tells the PCM that the button has been pressed. So it won't matter if you used it daily or never, you can still get ESS error messages if there's a MISFIRE, etc.

second 9mentioning this because there's too much crap info out there on that system and battery)
- what does bypassing the aux battery have to do with troubleshooting a misfire or rough running or check engine light.
That aux battery won't cause rough idle, rough running or misfires.

The codes were the tell - and the dealership figured it out.
The rough running, the misfire - those are the reasons for the ESS errors you had.

 

[AustyPosty]

No.

I have heard of the reliable Toyota brand fumbling bad on 100,000+ engines failing in the new tundra though

 

[Clark222]

You just word for word described whats going on with my jeep. Same year, same symptoms, same codes, 49000 miles. Tearing it down at the dealer now with minimum expected blown head gasket.

July 12, 2024.

2020 Jeep Gladiator sport... 36,450 Miles. Suddenly developed rough idle last week after 2-hr / Hwy speed travel. A couple days later the Stop/Start Service warning illuminated on dash. Rough idle seemed to occur mostly on startup, both cold and warm engine.
With a day or two the Stop/Start Service AND Engine light illuminated. Never use Start/Stop. Turned off on console AND bypassed with Tazer JL.

Troubleshooting....Bypassed auxiliary battery and continued to receive Start/Stop Service warning AND engine light. Diagnostic code indicated misfire on cylinder one. Took to dealership at the beginning of this week.

Result.... Cracked head. Left/front near cylinder one. Outside of 36K warranty but still covered under powertrain warranty. Service advisor said there have been other 3.6L Pentastar with this problem. Didn't say how many....

Btw,.... Same vehicle needed rear axle replaced at 9K mile due to rear diff being bad from the factory. Hmmmm???

 

[GigaChad2.0]

Are you able to share how the situation resolved? My 2019 GC Limited - same issue, 57k miles. Dealer quoting $13k for a new engine

You just word for word described whats going on with my jeep. Same year, same symptoms, same codes, 49000 miles. Tearing it down at the dealer now with minimum expected blown head gasket.

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