626,000 mile Pentastar teardown

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...
That depends on expectations. I think most here will consider 626k to be a excellent service life. I'm actually surprised the guides and tensioners lasted that long.
 
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Hopefully for FCA the new dual DI Pentastar will also have the same reliability. I would be interested in how the rest of the vehicle held up; rest of drivetrain, diff, trans, suspension and interior etc... That would be very interesting as well.
 
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Sounds like it had an oil change every 6 weeks based on some of those numbers using synthetic oils. Possibly once a month if it ran a 7 day work week. I didn't listen to the full video so not sure if it mentioned oil weight. Impressive nonetheless.
 
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Quite impressive. I still think I want a Pentastar for my next engine. At least the port injection one, dunno about DI or start/stop (call me a Luddite I don't care). I have to wonder if the fuel savings on 5W20 (as opposed to 5W30) would have paid for an engine replacement after 626k. Pure speculation I know, but if the owner ran 5W20 FS on 8k OCI's and managed this... makes one wonder. Nothing lasts forever, everything needs a repair or two, so it can become a balancing act between downtime, fuel cost and repair cost.
 

CT8

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The engine parts would last quite a bit longer. We must remember that an engine at stabilized operating temperature has minimal wear.
 

4WD

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Originally Posted by buster
That is excellent service life. Good oil, and some outlaw oil, good engine and driven 285 miles per day.
Fixed it Buster
 

JHZR2

Staff member
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Originally Posted by wwillson
https://www.thedrive.com/news/34672...ysler-pentastar-v6-is-after-626000-miles Looks like the internals were in good shape except for the timing chains and tensioners. My question is would these timing chains have lasted longer with thicker oils?
There's a major fallacy that timing chains last forever... They dont; they wear (some call it "stretch"), as do some of the cogs. Tensioners can "last" a long time (in calendar life - for example I have original ones in 40 year old diesel engines), but plastics in guides do get brittle and can break. The correct thing to do is to actually measure timing chain wear, in terms of how many degrees the chain is out of timing, and if it is low enough, repair with an offset woodruff key, otherwise replace. Replacement is the most prudent. Would a thicker oil, or perhaps even an oil with more AW/EP, even something with some solid lubricant (e.g. MoS2) help? Sure. But I have my doubts that its really prudent or correct to expect super long life out of any chain, and IMO it is not prudent to "trust" it any more than you would a timing belt, especially if your vehicle is getting up in miles. Visual observation is the only correct path, and replacement of it as a wear item when worn is important.
 
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Nice! As an former Pentastar design engineer I am slightly bias but the engine is really high quality. Few points from the development using tens of millions of dollars in analysis and testing regarding the oil and durability..... The lighter oil was chosen mostly for fuel economy BUT engineering is the science of compromise. You help one thing but hurt another. A thicker oil will reduce timing chain and tensioner wear because the center timing chain idler doesn't go fully hydrodynamic till about 1650rpm on 5w-20. So, a thicker oil will lower that number slightly and with general loads/speeds the engine spends a lot of time around 1500-1750 rpm with the 8 speed. So thicker oil is a win there. Additionally, the earlier engines had what was called the "McDonald's Arches" in the idler bearing which was intended in making a more uniform distribution but in actuality acted as a knife edge. This design was changed around 2014 to a smooth bearing. So overall timing chain issues will likely follow the 2011-2014 engine years more than 2014+. Where you lose.... The head is very complicated with a Type II valve train. Meaning lots of things to pressurize and pump up at start up. A thicker oil didn't do so well here (on long sit times +cold start) and contributed to a overall increased engine wear especially in the head and cam bearings. Last point. This engine needs occasional WOT runs if you want it to last. Granny cycling is bad for it. So bad for it we actually created a new granny cycle test during the cylinder #3 misfire issue. The highest wear is in the valve guides, because of tight valve stem seals (for emissions, reduce oil burn). They basically dry out. When you go WOT/high rpm/load you get some fresh oil in there and this keeps the wear down. Thicker oil might not help this condition but we also change the valves/guides/seals in 2014+. Not sure the impact. Cheers! Kevin PS. Turn off stop start and do not run e85 if you are concerned about engine wear. Eats the engine alive.
 
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Originally Posted by 4WD
Good info … I'm gonna have to help those valve stems more often 🏎
I do as well! Every highway ramp oilburner For the record I have a Chrysler 300S RWD with 165K going for 300K. I run 5w-20 in the winter and 5w-30 in the summer because of the cold start issue. Best car I've owned so far. Other than the bluetooth module. Just blew out my second...
 
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He mentions in the video about the valvetrain being the weak link.. wonder if he had any issues there? To me the weak link would be plastic tensioners and guides when you go as far as to design with 4 bolt mains. He also said engine had to be most likely pulled to change the tensioners and guides. Not sure any oil or weight would have made a difference.. all of those heat cycles on plastic make them brittle. He paid $350 for a used engine.. not sure if doing preventitive maintenance and changing them at 300K would have been a better outcome. Cost wise was cheaper to not do it and wait until failure. If engine would have been needed to be pulled to change tensioners may as well swap in a lower mileage one.
 

4WD

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We had a 2007 C300 3.5L for 140k and then got the 1st Pentastar in a 2013 Charger - my son drives it now. I just got a 2020 Rubicon … and honestly it was hard to find a Pentastar based unit with the options I wanted. Another guy at work was shopping another (has 2 Rubicons) and had the same problem … I wonder if Jeep is not moving too fast towards the I4 TDI ?
 
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Soooo, how many transmissions ? Sorry, had to. The interior volume on the promaster is second to none.
Originally Posted by OIL_UDDER
Nice! As an former Pentastar design engineer I am slightly bias but the engine is really high quality. Few points from the development using tens of millions of dollars in analysis and testing regarding the oil and durability..... The lighter oil was chosen mostly for fuel economy BUT engineering is the science of compromise. You help one thing but hurt another. A thicker oil will reduce timing chain and tensioner wear because the center timing chain idler doesn't go fully hydrodynamic till about 1650rpm on 5w-20. So, a thicker oil will lower that number slightly and with general loads/speeds the engine spends a lot of time around 1500-1750 rpm with the 8 speed. So thicker oil is a win there. Additionally, the earlier engines had what was called the "McDonald's Arches" in the idler bearing which was intended in making a more uniform distribution but in actuality acted as a knife edge. This design was changed around 2014 to a smooth bearing. So overall timing chain issues will likely follow the 2011-2014 engine years more than 2014+. Where you lose.... The head is very complicated with a Type II valve train. Meaning lots of things to pressurize and pump up at start up. A thicker oil didn't do so well here (on long sit times +cold start) and contributed to a overall increased engine wear especially in the head and cam bearings. Last point. This engine needs occasional WOT runs if you want it to last. Granny cycling is bad for it. So bad for it we actually created a new granny cycle test during the cylinder #3 misfire issue. The highest wear is in the valve guides, because of tight valve stem seals (for emissions, reduce oil burn). They basically dry out. When you go WOT/high rpm/load you get some fresh oil in there and this keeps the wear down. Thicker oil might not help this condition but we also change the valves/guides/seals in 2014+. Not sure the impact. Cheers! Kevin PS. Turn off stop start and do not run e85 if you are concerned about engine wear. Eats the engine alive.
Completely different animals, but my 5.4 - a junkyard engine - has always been pretty noisey. Except when I run the living daylights out of it. It is whisper quiet after pulling at hill at 4500 RPM for 4 or 5 minutes. Smoother running too.
 
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...
Originally Posted by OIL_UDDER
Nice! As an former Pentastar design engineer I am slightly bias but the engine is really high quality. Few points from the development using tens of millions of dollars in analysis and testing regarding the oil and durability..... The lighter oil was chosen mostly for fuel economy BUT engineering is the science of compromise. You help one thing but hurt another. A thicker oil will reduce timing chain and tensioner wear because the center timing chain idler doesn't go fully hydrodynamic till about 1650rpm on 5w-20. So, a thicker oil will lower that number slightly and with general loads/speeds the engine spends a lot of time around 1500-1750 rpm with the 8 speed. So thicker oil is a win there. Additionally, the earlier engines had what was called the "McDonald's Arches" in the idler bearing which was intended in making a more uniform distribution but in actuality acted as a knife edge. This design was changed around 2014 to a smooth bearing. So overall timing chain issues will likely follow the 2011-2014 engine years more than 2014+. Where you lose.... The head is very complicated with a Type II valve train. Meaning lots of things to pressurize and pump up at start up. A thicker oil didn't do so well here (on long sit times +cold start) and contributed to a overall increased engine wear especially in the head and cam bearings. Last point. This engine needs occasional WOT runs if you want it to last. Granny cycling is bad for it. So bad for it we actually created a new granny cycle test during the cylinder #3 misfire issue. The highest wear is in the valve guides, because of tight valve stem seals (for emissions, reduce oil burn). They basically dry out. When you go WOT/high rpm/load you get some fresh oil in there and this keeps the wear down. Thicker oil might not help this condition but we also change the valves/guides/seals in 2014+. Not sure the impact. Cheers! Kevin PS. Turn off stop start and do not run e85 if you are concerned about engine wear. Eats the engine alive.
I like this thinking. Most engines do like to be wound up now and then. I am fortunate to live on top of a hill. After a trip to the store where the SkyActiv motor is cruising at less than 2000rpm for the most part I make it a habit of going up this half mile stretch of hill in sport mode.
 
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I have been on the fence regarding 0W-20 versus a thicker oil in this engine. I have a friend down the street who runs 0W-40 in his 3.6L and he has not reported any issues by doing so. Curiously enough, his oil pressure is the same as mine and with no BPV in the oil filter (it is a cartridge), I wonder what the internal bypass pressure is as I would have assumed he would see a marked pressure difference (at least when the engine is cold). I added a catch can to mine (UPR) and initially (after about 200 miles) it had only trapped about 1/2 teaspoon), however, it now (after 600-700 miles) has trapped a few ounces of oil. I attribute the initial low amount to the hoses and filter media being dry because they were new. This is oil that would have been introduced into the intake system and subsequently burned in the combustion chamber. I added this text because it is strange the 3.6L has that much oil vapor in the system, yet has tight valve seals--to wit what is causing the vapor? The oil type does not seem to matter either based upon what I see posted in a couple of the Jeep forums, even oil with good NOACK ratings produces oil that is trapped in the catch can. At any rate, really nice to see a Pentastar (especially a Gen 1 that had head issues early on) with that many miles on it. The 4 bolt mains and the size of the main and rod journals likely contribute to their durability and I assume those carried over with the Gen 2 engine (which is what the Jeep JL Wranglers have). FCA re-designed the heads and valvetrain, though I do not recall reading anything about the timing chains or improvements on the timing system on Gen 2 engines. After seeing the video--what are your thoughts? 625K is a great run and 0W-20 (what is specified for the Gen 2 series, though the Gen 1 had 5W-30 specified in different parts of the world) is just fine or would you up the viscosity to an xW-30?
 
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Location
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i wish I had some more data for you 2015_PSD, Unfortunately I left the company as the Gen II was kicking off. I do know the engineering team was VERY nervous on the 0w-20 stuff and it was 100% for fuel economy. My personal opinion knowing the bearing surface area would not have gone up because of the cost I would go up a notch in weight. Not a lot of downside for the margin. Also, we are designing for 150-200K max, not 200k+ so that is always something to think about when OEM's make recommendations. I would like to note there was this bearing coating they started using called iROX which was very impressive at the microscopic and testing level. It had to go on the front and back bearings to pass Stop-Start because of wear and was very expensive. They likely added that to the rest of bearings to make them work but I don't know for sure, I will have to ask. Regardless, the bearing surface area did not likely increase so from a basic physics point of view your hydrodynamic response to "filling it with water" as we called it will not go in a safer direction at lower rpm.
 
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