2018 Wrangler JLU 3.6l Engine Failure

[croppz]

it's extremely common on the 3.6l PUG engine. this is from first hand experience watching these come in half a dozen per week. i personally believe it's under torqued heads at the plant

Slightly off topic but what are you seeing with the 2.0Ts?

also would make sense about the undertorqued heads. That’s the same problem the 2.0T accords have and it causes head lift and poof gasket done.

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[alphawolff]

Slightly off topic but what are you seeing with the 2.0Ts?

also would make sense about the undertorqued heads. That’s the same problem the 2.0T accords have and it causes head lift and poof gasket done.

the 2.0l tends to leak from 3 different orifices leading to blown heads if ignored.

 

[58Willys]

At 50-70K? I never have great confident with Jeep reliability but 30% of the 3.6s have blown gasket at 50-70k miles? I find that hard to believe. And 30% and 1/33 are two different things. 30% is 30%. 1/33 is like 3%.

Yea, I should have said 1/3.

 

[siggy]

Somewhere here is a poll on blown head gaskets, I think about 30% responded with blown head gaskets. That's 1/33.

I’m gonna go on a limb here and say math isn’t your strong suit.

 

[Odyssey USA]

The thinking is the gaskets themselves aren't the problem but they are inadequately torqued from the factory. The problem doesn't repeat once addressed.

Correct! Never overheated here. Babied life. Had to replace cams and now one head gasket failed in ‘25. (I’m going to replace both banks’ head gaskets and cylinder heads) Tear down revealed 5 loose (er) head bolts. Inconsistent clamping force and I just had to send back a new right bank head that had a deck surface finish that was too rough. Like rough enough to create shadows when shining a flashlight at an angle on the deck. In the industry it’s called “waviness.” As a former automotive machinist, either the mill table was able to move up and down or the bearings were going bad in the milling/surfacer head. You look for three things. Flat. Smooth (RA, roughness average) but they have to have an uber expensive profilometer that some shops won’t have. No waviness akin to rumble strips on the side of the road. That head won’t seal.

I was looking at the used, left bank head and found an aluminum machining chip lodged in a cam journal. SMH

I’ll be removing all the galley plugs on these new heads, inspecting oil galleys, and blowing them out with compressed air.

 

[DaltonGang]

2018 Wrangler JLU
Coolant leaks from reservoir and at hose connector are common. Infiltrated cylinders and cracked block at 55,000 miles. New engine on my dime. At 1000 miles on new engine me and my 88 yr old father were stranded on freeway with jeep overheating. Possibly oil cooler clip breaking. Red Temp light came on then the A. Then smoke. I thought it was on fire. Terrifying! Temp gage showed nothing wrong prior. Towed to dealer again. Mind you I was without my jeep for 6 weeks already. Jeep Cares already notified. Will take up the chain of command.

What weight oil were you using on your engines, and how often was the oil changed???

.

 

[Freebird805]

What weight oil were you using on your engines, and how often was the oil changed???

.

2x per year or every 4000 miles. All done at dealer except 2x at reputable shop. Not sure what weight used. I need to look back at receipts.

 

[DaltonGang]

2x per year or every 4000 miles. All done at dealer except 2x at reputable shop. Not sure what weight used. I need to look back at receipts.

You answered my question. If it was changed at the dealership, then it was 0w-20 oil. Sorry for your losses.

 

[OminousSkitter]

You answered my question. If it was changed at the dealership, then it was 0w-20 oil. Sorry for your losses.

Are you implying thin oil caused a head gasket failure? I thought all the arguments against 0w20 were centered around the cams/rockers.

 

[DaltonGang]

Are you implying thin oil caused a head gasket failure? I thought all the arguments against 0w20 were centered around the cams/rockers.

No, just curious.

 

[MikeinMD]

I've got an 18 Sahara 3.6 with 108K on the odometer that is currently at the dealership for a P0301 cylinder 1 misfire which is apparently a head gasket failure. Under Maxcare Lifetime, they are replacing the head and also plugging a leak in the oil pan along with some other miscellaneous items. Service ticket attached.

If these all get approved, any idea how much it would have cost without Maxcare? Wondering if it's paid for itself in one trip to the dealership.

I posted this in another older thread the other day, so apologies for anyone that read it.

 

[mwilk012]

Slightly off topic but what are you seeing with the 2.0Ts?

also would make sense about the undertorqued heads. That’s the same problem the 2.0T accords have and it causes head lift and poof gasket done.

Hey don’t tell anyone, I’ve been making good money on those Hondas.

 

[Jtphoto]

Considering there are millions of 3.6L out there I,d say the failure rate is extremely low. Many of the failures (not all) in Jeeps are self inflicted but it has been noted that there is a high failure rate on replaced engines which comes down to the installer.
My personal experience is between all family vehicles, many high milers out of 15 3.6 engines from 2013 to present, ZERO failures. Current JL is at 136,000klm.
im not saying they are all perfect by any means and it does suck to have issues but that happens with any manufacturer. There are a lot of abused Wranglers out there that are used for what they are meant for so it no wonder if their failures may be higher. Not saying the OP abused his Jeep BTW.

 

[croppz]

Hey don’t tell anyone, I’ve been making good money on those Hondas.

1.5Ts leave my job on a sold work order faster than we can inventory them lol

 

[mwilk012]

1.5Ts leave my job on a sold work order faster than we can inventory them lol

At least they’re easy and relatively affordable. I don’t think we’ve ever had the chance to sell spark plugs on one though, it’s always coolant in the hole.

Honda is on my naughty list right now.

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