3.6 Reliability Issues Resolved ?

[oldironsights]

Interesting thread.
Thanks for it.
I am one running 5w30 high detergent synthetic oil in his Glad.
I had already purchased the Valvoline R&P for another project(My Ford F150)
I used the oil in the 23 Sport purchased recently to flush out any sludge or debris on the 3.6 due to its 57k miles as a rented mule.
One thing I have observed with changing viscosity, is how it affects the cam phasers as the viscosity increases.
Heavier oil increases latency; lighter decreases it.
The coyote I traded for the Glad acted the same.
If you follow lake Speed, The Motor Oil Geek, you can learn from his labors.
He has shown the factory 0w20 saves fuel & reduces upper end wear at the expense of bottom end wear.
By increasing the viscosity , like I just did, I am now using more fuel & sacrificing upper end wear in favor of protecting the bottom end.
Where are the weak points of the Pentastar?
On the top end. The bottom is strong enough to survive the 0w20 in most driving conditions.

I live in the south where it is hot more than it is cold & my old school fool just won't convince me otherwise to run a 0w20 during summer.
I like the higher viscosity in summer. Engine temp can be 90 @ AM start up already.
Oil degrades. Change it often.
Got a fresh jug of NAPA 0w20 ready for October.

I plan to reverse my criminal ways then & see if I can hit 30 mpg & for how long with more o2 in the air with the A/C off.

Hope this helps.

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[ShadowsPapa]

Interesting thread.
Thanks for it.
I am one running 5w30 high detergent synthetic oil in his Glad.
I had already purchased the Valvoline R&P for another project(My Ford F150)
I used the oil in the 23 Sport purchased recently to flush out any sludge or debris on the 3.6 due to its 57k miles as a rented mule.
One thing I have observed with changing viscosity, is how it affects the cam phasers as the viscosity increases.
Heavier oil increases latency; lighter decreases it.
The coyote I traded for the Glad acted the same.
If you follow lake Speed, The Motor Oil Geek, you can learn from his labors.
He has shown the factory 0w20 saves fuel & reduces upper end wear at the expense of bottom end wear.
By increasing the viscosity , like I just did, I am now using more fuel & sacrificing upper end wear in favor of protecting the bottom end.
Where are the weak points of the Pentastar?
On the top end. The bottom is strong enough to survive the 0w20 in most driving conditions.

I live in the south where it is hot more than it is cold & my old school fool just won't convince me otherwise to run a 0w20 during summer.
I like the higher viscosity in summer. Engine temp can be 90 @ AM start up already.
Oil degrades. Change it often.
Got a fresh jug of NAPA 0w20 ready for October.

I plan to reverse my criminal ways then & see if I can hit 30 mpg & for how long with more o2 in the air with the A/C off.

Hope this helps.

Remember, in the different climates, only the number before the W really counts - cold start viscosity.
0W to 5W in warm climates makes sense where you don't see something like sub-40s on a cold start morning.
But the 20 vs 30 - that doesn't matter as both are operating under the same engine temperatures. Since we both probably see 200 degree engine temperatures, it makes no sense.
Where I see cold mornings and someone in AZ may not, them going to a 5W instead of 0W might make sense.

As far as AC on or off - AC off only saves fuel below about 50. Speeds over 50, AC on, windows up, saves fuel. There's been a lot of studies on that.
The drag of an open window at highway speed uses more fuel than the AC does.

 

[oldironsights]

You may be right, SP, but I am a stubborn old boomer that is slow to change..........
Hell, I'm slow @ everything now.
Time to hang a red triangle reflector out back......

 

[Mad Mac]

Clearly, I've been doing this all wrong.
On average, we kept vehicles ten years
and 120,000 miles.

The exception is my wife's 2002 Yukon
now the daily driver for my grandson.
Don't know how many miles it has.

Heck. I had a 1998 Yamaha V-Max
I rode 67,000 miles in six years.

Lately, I've slowed down.
A lot.

 

[Rubiconda]

LOL - only in that there's no damage. Not success in preventing the cam failure.
It took 10 seconds to find Jeep people running "heavier oil" and then STILL having cam failures.
And there's several here with over 100,000 miles using the recommended oil.
So.............
Oil won't matter, in other words. If it's gonna happen, it will. If it's not going to happen, it won't.

I can appreciate your “what’s meant to be will be” take on it! One serious question, mechanically, does it make sense to add that aftermarket check valve to keep the oil in the engine or no? I’m assuming, no.

 

[ShadowsPapa]

I can appreciate your “what’s meant to be will be” take on it! One serious question, mechanically, does it make sense to add that aftermarket check valve to keep the oil in the engine or no? I’m assuming, no.

No. It's a feel good thing at best. But these start up with the oil pump in high volume mode. The oil pressure builds so fast the display doesn't keep up with the numbers, and you have pressure by the time it's running. The oil filter also holds a really tiny amount of oil in the grand scheme of things.

 

[Mr Miami]

I don't quite understand this. If you are "looking into getting my 6th JT" that assumes you have had 5 others. Unless they were diesels, you have had the 3.6's. So what experience did you have with them? As was mentioned, if you have read all the stuff on the internet (if it's on the internet it must be true) then you can find any opinions you want about any engine you want, any brand.

If after 5 JT's you still aren't comfortable with your own experience, then follow a group who say their 3.6's blew up on the way home from the dealership or the ones with 200k miles and only changed the oil twice in 10 years. They're all out there.

 

[oldironsights]

I have no faith in that aftermarket pressurized oil filter housing being sold as a solution to start-up starvation.
If anyone can look back to the Covid era, they may remember the supply & logistical shortages.
One failure point during production was the lack of the ordered chipsets with top tier processors.
Vehicles were delayed in reaching final production or delivery due to the shortage.
Either vehicles were delivered with deleted features, or buggy, alternative, slower processors.
I have measured the time it takes my 2.0L turbo & the 3.6 Penta from energizing the vehicle to oil pressure light fading away.
About seven seconds.
Of those seven seconds, five were involved with booting the vehicle's onboard PC.
Two seconds or less were involved with achieving enough oil pressure to pressurize the lifters, rockers & cams.
I can see where one can be mislead by the latency.
My 3.6 starts up & runs fine with either 0w20 or 5w30.
I just used what I had on hand for the mission of breaking up carbon if any existed(no evidence after 1200 miles of 5w30 restore & protect)
The NAPA 0w20 with moly is sitting in my shed & will be ready for installation in the Glad this October.
Snow was insane on inauguration day & my old one-wheel drive Ford was stuck at home.
I will be prepared this time.........................

 

[Deleted member 66831]

It’s still in issue, what severity we will never know. Parts in some regions are MONTHS of waiting. The solution is jeep putting in the same parts. If your looking for an ironclad truck, YMMV.

 

[ShadowsPapa]

You have to watch the numbers, not so much the light.
Processors weren't changed to "slower", they simply didn't get any. It's urban legend that they used slower, inferior "processors". (having worked for a company deep in EE, I learned a few things) But people will post that stuff on the internet, those not knowing better will believe it. Jeep buys the units, not "processors". Uconnect - at least some versions - were Samsung.

Watch the oil pressure build from the moment the starter engages, not any other time. Nothing else matters.
Once you build pressure, you are already going to see oil spray onto parts. Pressure cannot exist until the oil volume has filled all gaps, nooks and crannies.
I use a speed handle to prime oil pumps in the engines I build. I have a mechanical gauge in the system, valve cover(s) off, watching for oil. I can feel the pump's resistance as things fill with oil and pressure starts to build. You won't see pressure until there is oil coming out of some areas, like the rocker arm area of an engine.
As a friend proved, unless there is a leak, or restriction, on a properly operating oiling system, pressure is within tenths of a pound front to back.

 

[oldironsights]

Being only months into this Glad (acquired 30Jun25), the "Urban Legend" theory sounded plausible & I adopted it.
Was not aware this has a variable oil pump.
Having spend my time working on Diesels, most of this gasoline stuff is foreign to me.
I have replaced many, many cams over the past 30 years, but on DD Series 60 & Cummins ISL.
Not planning on replacing any more.

 

[ShadowsPapa]

The oil pumps in these have a solenoid that controls displacement. They start out in high volume mode and then drop back to roughly 30 psi regulation in lower volume mode.
They are vane type, chain drive off the crankshaft.

The oil pumps I'm more used to are gear types, driven half engine speed by the camshaft. They can't supply the volume of oil these can.

So far, I've replaced a lot of cams, but never in my own vehicles unless I was doing a rebuild and wanted a different profile, etc.
Hopefully, that trend continues!

 

[oldironsights]

Hopefully, that trend continues!

Amen!

 

[chr15m]

You have to watch the numbers, not so much the light.
Processors weren't changed to "slower", they simply didn't get any. It's urban legend that they used slower, inferior "processors". (having worked for a company deep in EE, I learned a few things) But people will post that stuff on the internet, those not knowing better will believe it. Jeep buys the units, not "processors". Uconnect - at least some versions - were Samsung.

I cannot say a whole lot due to "reasons", but am in the field of engineering that would insight on these things. I was happy to see these myths disappear, so odd to see it brought up again.

Pappys right on this one, the development doesn't work like that, things are not back stocked or stored for use in the possible occurrence of an issue like COVID, that goes beyond making no sense to me and really speaks to the source of that having zero knowledge on how this industry works. Separate "processors" as they're being referred to here with "slower" abilities do not get suddenly produced. Possibly older sets that had already been produced were an alternative and that could explain the absence of certain options being available, previous generations prior to apps being added would support that. Those would primarily be in the vehicle manufacturers stock and be a choice they would have to deliberate on. But entirely new set infrastructure to be added to line development that simply had reduced capabilities is not a thing and would take more time than waiting on delays. The real issues that lead to that happening was primarily in a different industry and that was shipping and economic fear. When someone is afraid that their bottom line is at risk they start pruning, hesitation to delay for parts orders were a thing and ultimately the vehicle manufacturers played a part in their shortages. Shipping and inter country transport stops out of fear of spreading it compounded that issue. Its like the gate at Disney, mid-day traffic is our normal, try getting in at opening time. That's what all these manufacturers had to deal with as a result. Youre not going to get it right away, it'll show up when it shows up.

 

[daveb]

in number 6, since 1986.

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