3.6 longevity solution

[m3reno]

Went by my dealer yesterday and spoke with the owner who owned every type of Wrangler He told me the problem with the lifters and cams comes down to two things. The oil required is too thin and letting your vehicle idle for extended long intervals. He stated that the oil shears down over time and the oil pump struggles to pump the thinned out oil and also struggles to maintain the required pressure which is needed to have everything lubricated. So his solution was to change the oil at 5,000 miles and bump it to 5w 30 and no prolonged idling. I wonder if the motor's that had issues on this site did any type of prolonged idling.

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[azwjowner]

All the Dodge Charger police cars with the Pentastar and thousands of hours of idling pretty much blow that theory out of the water. The internet amplifies problems. Overall the engine is extremely reliable. Does it have a weakness? Sure.

 

[Phrank]

The motor will last forever, so long as you don't actually use it - tell me you're a dealer without telling me you're a dealer.

 

[Ratbert]

Amsoil. Around here the answer is always Amsoil.

 

[Powelligator]

Jeeps idle a lot, at least the ones used on trails. I'd say that heat buildup will shorten the life of a lot of components under the hood long before the engine itself fails. And it doesn't matter what engine it's running either.

 

[JLRyder]

Staring to wonder if the clickbait’ness of these threads are not somehow paid for…use whatever oil you want, personally I’ll stick w/ whatever the book recommends. My interval is 3mo or 3k whatever comes first just like it was back in the 90s. Say what you want…it’s my money and my 75k mile 2019 still purrs like a kitten.

 

[roaniecowpony]

All the Dodge Charger police cars with the Pentastar and thousands of hours of idling pretty much blow that theory out of the water. The internet amplifies problems. Overall the engine is extremely reliable. Does it have a weakness? Sure.

Ahh, say it ain't so. A police cruiser with a V6? I'm surprised the PDs even bought something without a V8. No wonder the criminals aren't scared.

 

[roaniecowpony]

Jeeps idle a lot, at least the ones used on trails. I'd say that heat buildup will shorten the life of a lot of components under the hood long before the engine itself fails. And it doesn't matter what engine it's running either.

I sure wish that were true. But it wasn't my experience.

Idling itself isn't the worst thing an engine can do, especially a modern EFI engine, that has a well controlled idle air-fuel mixture, modest cam timing, and a good oil pump like the Pstar. It's not a splash lubricated cam and lifters like an old school V8.

 

[m3reno]

What I got out of the conversation was that at idle the pump struggles and the PSI are low at idle. That and the thinner sheered oil is the issue at idle, which is the reason for the 5000 mile oil changes. Not sure how true it is, but just relating what was said. He also said that he has seen his fair share of failed 3.6's and this was his conclusion. He also said the 2.0 was a much better engine which kinda shocked me.

 

[NPC 20883467]

What I got out of the conversation was that at idle the pump struggles and the PSI are low at idle...

That's not a true statement...

The oil system in these units uses a solenoid to hold oil pressure at 30 psi all the way from idle to 3K RPM, when the solenoid opens up to allow full pressure (~75 PSI).

Which means your engine is receiving 30PSI at idle, and it's receiving that same 30 PSI working a lot harder at 2999 RPM. It doesn't take a Logician to figure out that with a constant, unchanging flow of oil, the motor is better off at idle.

Also... With a constant oil pressure, the engine does not see it's maximum flow volume until it is completely warmed up to operating temperature. That said, in the morning I let the Jeep idle until it is fully warmed up and getting the maximum flow rate through the engine before I go anywhere.

 

[alphawolff]

All the Dodge Charger police cars with the Pentastar and thousands of hours of idling pretty much blow that theory out of the water. The internet amplifies problems. Overall the engine is extremely reliable. Does it have a weakness? Sure.

Those cars are ran hard and their oil is changed consistently. They're also the absolute easiest body style to do the rocker arm repairs. If they start ticking they're fixed instantly before any cam shaft damage occurs, so the repairs are cheap.

What I got out of the conversation was that at idle the pump struggles and the PSI are low at idle. That and the thinner sheered oil is the issue at idle, which is the reason for the 5000 mile oil changes. Not sure how true it is, but just relating what was said. He also said that he has seen his fair share of failed 3.6's and this was his conclusion. He also said the 2.0 was a much better engine which kinda shocked me.

That's not a true statement...

The oil system in these units uses a solenoid to hold oil pressure at 30 psi all the way from idle to 3K RPM, when the solenoid opens up to allow full pressure (~75 PSI).

Which means your engine is receiving 30PSI at idle, and it's receiving that same 30 PSI working a lot harder at 2999 RPM. It doesn't take a Logician to figure out that with a constant, unchanging flow of oil, the motor is better off at idle.

Also... With a constant oil pressure, the engine does not see it's maximum flow volume until it is completely warmed up to operating temperature. That said, in the morning I let the Jeep idle until it is fully warmed up and getting the maximum flow rate through the engine before I go anywhere.

Actually, both cylinder heads are getting 60 PSI even at idle. They're plumbed differently and always get full pressure regardless of pump state. I didn't know this either until I was investigating the 3.6L hesitation issue. Part of the diagnostic was checking the cylinder head oil pressure at the VVL solenoids with a special tool (the same oil path feeds the rockers), and sure as shit they're 60 PSI even at idle while the dash says 30 PSI. This is true for the PUG engine. I don't know if the original pentastar operates this way as I've never tested it, nor does the original pentastar have VVL solenoids to even test from.

Ahh, say it ain't so. A police cruiser with a V6? I'm surprised the PDs even bought something without a V8. No wonder the criminals aren't scared.

The 5.7L makes 375hp. The 3.6L makes 300. It's barely a difference, 300 is plenty when it comes to hauling ass.

 

[NPC 20883467]

Actually, both cylinder heads are getting 60 PSI even at idle. They're plumbed differently and always get full pressure regardless of pump state. I didn't know this either until I was investigating the 3.6L hesitation issue. Part of the diagnostic was checking the cylinder head oil pressure at the VVL solenoids with a special tool (the same oil path feeds the rockers), and sure as shit they're 60 PSI even at idle while the dash says 30 PSI.

That's good to know... In an effort to get max life out of the valvetrain, I was seriously considering hacking the pump solenoid so that the pump always put out max pressure. You're telling me that's not necessary....

The 5.7L makes 375hp. The 3.6L makes 300. It's barely a difference, 300 is plenty when it comes to hauling ass.

Indeed... I can see where the Station Wrangler guys might want a 392, but I've always regarded my 2-door 3.6 as being stupid fast for a Jeep.

 

[autotragic]

All the Dodge Charger police cars with the Pentastar and thousands of hours of idling pretty much blow that theory out of the water. The internet amplifies problems. Overall the engine is extremely reliable. Does it have a weakness? Sure.

https://www.thedrive.com/news/india...rangos-because-stellantis-allegedly-wont-help

 

[NPC 20883467]

https://www.thedrive.com/news/india...rangos-because-stellantis-allegedly-wont-help

At Stellantis, you're not the customer. You're the mark.

 

[autotragic]

Ahh, say it ain't so. A police cruiser with a V6? I'm surprised the PDs even bought something without a V8. No wonder the criminals aren't scared.

To be fair standard cop cars have never been fast just fast enough.
A Dodge Durango with a Pentastar V6 is faster than an old 4.6 Crown Vic.

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