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Old 06-14-2012, 10:42 PM   #1201
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Not sure if this has been asked before, but has anyone snooped around the Jeep Grand Cherokee boards? If it's a design flaw, then this would be a known problem by now with the '11 GC with the same exact motor.

I did a quick look and have not found anything on ticking heads in the '11 GC's.

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Old 06-14-2012, 10:46 PM   #1202
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Was the head/manifold design changed in the Wrangler? Why not all these issues in the 200, GC, whatever else has the 3.6 now...?

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Old 06-14-2012, 10:50 PM   #1203
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Originally Posted by MikeK46 View Post
Not sure if this has been asked before, but has anyone snooped around the Jeep Grand Cherokee boards? If it's a design flaw, then this would be a known problem by now with the '11 GC with the same exact motor.

I did a quick look and have not found anything on ticking heads in the '11 GC's.
Some guy on here had the same issue in his GC. having said that, i searched around a lot for pentastar issues, and the ticking appears to be almost entirely for JKs. That could be related to the fact that a lot of people who buy wranglers are enthusiasts and are more aware of engine problem noises

the engines are slightly different, but i assumed it was in the programming. for example:
Grand Cherokee: 290HP pentastar
Town and Country: 283HP pentastar
JK: 285HP pentastar
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Old 06-14-2012, 11:02 PM   #1204
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You would think they would have heavily tested the motor for this sort of issue prior to putting it in every Chrysler product. Don't they put 10s of thousands of 'miles' on the engine before it goes to production? I am not buying the design flaw theory yet.
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Old 06-14-2012, 11:26 PM   #1205
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the engines are slightly different, but i assumed it was in the programming. for example:
Grand Cherokee: 290HP pentastar
Town and Country: 283HP pentastar
JK: 285HP pentastar
Most likely just differences in intake plumbing & exhaust system.
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Old 06-14-2012, 11:28 PM   #1206
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i still think this is a machining issue...hence the valve seats being out of spec causing the valve to tick and the engine to misfire. i doubt these engines are running hotter everyday with more miles we put on them. why would heat from the built in manifolds cause one valve seat to fail and become out of tolerance through warpage? the whole damn head would warp and the head gaskets would be failing well before the aluminum erodes, no?

however, if the tolerance is off on the valve seat from the factory the mileage will continually wear on the aluminum where the valve is contacting it causing the tick to increase audibly overtime. this also explains why some have the tick at purchase and others many miles later. the more out of tolerance the machining is from the start, the sooner the wear and tick and CEL appears. the tolerance in the beginning is what is causing the variable fail times/mileage.
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Old 06-15-2012, 12:47 AM   #1207
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i still think this is a machining issue...hence the valve seats being out of spec causing the valve to tick and the engine to misfire. i doubt these engines are running hotter everyday with more miles we put on them. why would heat from the built in manifolds cause one valve seat to fail and become out of tolerance through warpage? the whole damn head would warp and the head gaskets would be failing well before the aluminum erodes, no?

however, if the tolerance is off on the valve seat from the factory the mileage will continually wear on the aluminum where the valve is contacting it causing the tick to increase audibly overtime. this also explains why some have the tick at purchase and others many miles later. the more out of tolerance the machining is from the start, the sooner the wear and tick and CEL appears. the tolerance in the beginning is what is causing the variable fail times/mileage.
I can't argue with your logic and i really do hope it's a manufacturing issue. when i picked mine up, i was aware of the tick issues due to this forum and i could hear a slight noise on the lot. However, I considered it normal valvetrain noise for the pentastar. I even mentioned it to the salesman. 1k miles later it was definitely louder and becoming a problem. the passenger side of my engine is completely silent, which is nice because it's a great way to prove that it's not injectors.

As mentioned, the manifolds should be the same on either side, along with the rest of the hardware. The only difference I can think of is the oil filler tube? Unless the oil flow is not symmetrical? So if the right head is ok, the design should be ok and we can assume it's some manufacturing issue. what really bugs me is that chrylser doesn't come out and say they had a manufacturing issue in the heads. if it's an engineering issue, they're screwed.
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Old 06-15-2012, 01:30 AM   #1208
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I can't argue with your logic and i really do hope it's a manufacturing issue. when i picked mine up, i was aware of the tick issues due to this forum and i could hear a slight noise on the lot. However, I considered it normal valvetrain noise for the pentastar. I even mentioned it to the salesman. 1k miles later it was definitely louder and becoming a problem. the passenger side of my engine is completely silent, which is nice because it's a great way to prove that it's not injectors.

As mentioned, the manifolds should be the same on either side, along with the rest of the hardware. The only difference I can think of is the oil filler tube? Unless the oil flow is not symmetrical? So if the right head is ok, the design should be ok and we can assume it's some manufacturing issue. what really bugs me is that chrylser doesn't come out and say they had a manufacturing issue in the heads. if it's an engineering issue, they're screwed.

if it does turn out to be an engineering using that effects ALL new 3.6L i think we are the ones that are screwed....they will not be able to handle that big of a repair job and will file for bankruptcy and we will be hung out to dry....i still say its limited to a large batch of poorly machined heads that have a valve seat or two out of tolerance. I have 2400 miles and no tick...
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Old 06-15-2012, 12:04 PM   #1209
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if it does turn out to be an engineering using that effects ALL new 3.6L i think we are the ones that are screwed....they will not be able to handle that big of a repair job and will file for bankruptcy and we will be hung out to dry......
Yup, then it would be time for a V8 swap. At least in my case.

At any rate guys, I wasn't arguing that this is an engineering issue. I just saw it on another forum and figured it would spark an interesting discussion over here. I got a really bad feeling when I read it, but now I am already thinking about being "forced" to swap a V8 in
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Old 06-15-2012, 12:22 PM   #1210
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This person is a technician for Chrylser and makes some good points:

"Well time will tell. I would say it will be a problem with everything that is getting the 3.6 heads from the same vendor, so the fiats lancia and possibly vw would not apply as they get their heads from a different plant.

Its happening on the durango, the caravan and the grand cherokee that I've seen personally. And its not rumor its fact, but its also fact that chrysler isn't gonna give all the facts because they don't want everyone to know all the facts."


If it's limited to just a specific plant that produced the bad heads, then it may not be that widespread, and Chrysler might decide to keep it on the DL.
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Old 06-15-2012, 12:41 PM   #1211
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I don't think Chrysler would even come close to thinking about declaring bankruptcy over this. How many 2012s Wranglers are out there? It does not seem to be affecting any other model. They probably sell 10,000 Wranglers per month and have a few months worth to fix eventually. However, if enough people don't raise awareness or a stink about this, they will try to sweep it under the rug.
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Old 06-15-2012, 05:37 PM   #1212
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You guys with the 2012 wranglers with the ticking. Take them back to the dealers and raise hell if you have to. Chrysler is well aware there's an issue with the heads. I'm not about to spend $34,000 on a vehicle and "wait" for a light to come on. Ask the dealer who told you to wait for the "light" to explain exactly what "light" would come on to show premature wear in the lifters, valves or cam shaft. Thats bull... Really ! If you can't get satisfaction from the dealer then get your area Chrysler service rep. involved. Good luck to you guys with this issue.
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Old 06-15-2012, 07:57 PM   #1213
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I don't think Chrysler would even come close to thinking about declaring bankruptcy over this. How many 2012s Wranglers are out there? It does not seem to be affecting any other model. They probably sell 10,000 Wranglers per month and have a few months worth to fix eventually. However, if enough people don't raise awareness or a stink about this, they will try to sweep it under the rug.
As of January Chrysler produced its millionth Pentastar engine. Are there a million Chrysler's on the road with this engine? I doubt it. How many of the million engines have bad heads? Is Chrysler going to fix them before they go into vehicles or deal with them one at a time? Only Chrysler knows and they'll never let the cat out of the bag. This could bankrupt them or hurt their rep real bad. They bet big on this engine, and I think there are a lot of Chrysler's with the 3.6L that have problems, time will tell.

Funny early on when they had issues with a few of these engines due to poor cleaning of the block because it had no freeze-out plugs they were quick to make it known to the public. This they are quiet about, because IMO it is a major issue. I hate putting off my purchase of a 2013 but I am.
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Old 06-15-2012, 08:12 PM   #1214
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This only seems to impacts some of the 2012 Wranglers. Are you aware of other models with this issue? Maybe there is an issue, but apparently it is from some heads that came from one supplier. Time will tell.
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Old 06-15-2012, 08:55 PM   #1215
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Aren't the heads manufactured at the same plant where the engines are assembled, Trenton South? I thought I saw heads being machined in the video shot at Trenton South. Maybe not.
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Old 06-15-2012, 08:58 PM   #1216
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This only seems to impacts some of the 2012 Wranglers. Are you aware of other models with this issue? Maybe there is an issue, but apparently it is from some heads that came from one supplier. Time will tell.

There are other models with the issue, it was mentioned in this thread.
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Old 06-15-2012, 09:40 PM   #1217
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Aren't the heads manufactured at the same plant where the engines are assembled, Trenton South? I thought I saw heads being machined in the video shot at Trenton South. Maybe not.
I recall the same thing... banks of head milling machines.

Thanks, Tomster, now I have to go look and see if I remember correctly...

Yeap. Here's a photo from allpar.com showing the head milling machines at Trenton Engine Plant from an article on the Pentastar and the new assembly plant:

Click image for larger version

Name:	1 Trenton heads.jpg
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Old 06-15-2012, 10:10 PM   #1218
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I recall the same thing... banks of head milling machines.

Thanks, Tomster, now I have to go look and see if I remember correctly...

Yeap. Here's a photo from allpar.com showing the head milling machines at Trenton Engine Plant from an article on the Pentastar and the new assembly plant:

Attachment 132321
Wow, now that looks expensive!
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Old 06-15-2012, 10:20 PM   #1219
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Wow, now that looks expensive!
Take a gander at the whole, new plant! After watching this 10 minute video, I don't know how they sell Jeeps so "cheap".

And, it looks like you can't blame humans for the engine assembly, they pretty much stand around and watch robots do most of the work.

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Old 06-15-2012, 10:55 PM   #1220
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Take a gander at the whole, new plant! After watching this 10 minute video, I don't know how they sell Jeeps so "cheap".

And, it looks like you can't blame humans for the engine assembly, they pretty much stand around and watch robots do most of the work.


Great post UHB!
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Old 06-16-2012, 03:44 AM   #1221
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I have been following this thread from the beginning. From what you've all reported I cannot recall any dealerships staff (service dept./managers) who have been given the chance to come up with an explanation of whats causing this. Not their fault. They are out of the loop. Chrysler has no clue or direction on a procedure for the dealer service departments (yet).
If you've had a service dept. thats not giving you BS consider yourself fortunate. There are some really good mechanics out there that, i am sure, would love to tackle this problem.

Let's look (recall threads)....and list common denominators (by no means complete.)

For instance the problem
-is evidenced by a ticking sound which gradually gets worse
-the actual failure indication (light on dash) manifest after first oil change.
-the actual failure indication happens at idle when temp approaches "red zone"
-new heads fix the problem
-suggestion that problem could arise after 1st fix

you get the point.

so lets say that after all facts are compiled that a cause could be posited as being:
Heat tolerance issues, causing component(s) failure, due to head/exhaust design.

Resolution/preventative measures:
1. increase radiator core size
2. change thermostat
3. oil viscosity.....
4. engine coolant upgrades
5. heat reduction measures

I don't know, i'm up way to early, and I am still pissed i won't let myself get a new Rubi. If I had one ^ thats what i'd do.
Man i hope you all are compensated for this BS you are going through.
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Old 06-16-2012, 06:57 AM   #1222
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The longer this goes on, the more I am leaning toward a design problem rather than a manufacturing problem, and that is NOT a good thing if it is. That would mean that the new head would eventually fail, and the one after that, etc.

No one wants to believe me about the "just in time" management philosophy. That's the way it is whether anyone wants to believe it or not. The auto makers cannot afford to tie up dollars in stockpiled parts or sub assemblies. Parts arrive at the assembly line "just in time."

The Trenton South Engine Plant is 40 miles from Toledo and a friend of mine who works on the assembly line at the Grand Cherokee plant tells me that engines are usually only a matter of hours old when they are installed in Wranglers. They DO NOT make them ahead of time and store them for later use.

So, for those who subscribe to the theory that there was a bad run of heads and the problem has been corrected, I'm afraid that is probably not the case. Why would the problem vehicles have such a huge range of build dates if there was just a bad run of heads at some point in time?

I suspect that the heads are being manufactured to specifications and that the specifications are the problem, i.e., a bad design. Why else would the problem continue over all those months?

I HOPE I AM WRONG! Someone, please, prove me wrong! Please!

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Old 06-16-2012, 07:15 AM   #1223
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No problems with either of my 2012's. Guess they engineered mine wrong too? I mean if was a engineering problem, wouldnt you see a lot more problems. You would see more bad ones than good ones right. They can't always make everything to spec. Many got through before it was caught. Thats what you get when you take the machinist out of equasion and put a robot loader in it's place.

I don't know how big of a sample lot they check, but today everything is checked on a CMM. Basically every dimension is probed from a known datum and follows a program with known values. Someone dropped the ball in inspection dept.
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Old 06-16-2012, 07:17 AM   #1224
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The longer this goes on, the more I am leaning toward a design problem rather than a manufacturing problem, and that is NOT a good thing if it is. That would mean that the new head would eventually fail, and the one after that, etc.

No one wants to believe me about the "just in time" management philosophy. That's the way it is whether anyone wants to believe it or not. The auto makers cannot afford to tie up dollars in stockpiled parts or sub assemblies. Parts arrive at the assembly line "just in time."

The Trenton South Engine Plant is 40 miles from Toledo and a friend of mine who works on the assembly line at the Grand Cherokee plant tells me that engines are usually only a matter of hours old when they are installed in Wranglers. They DO NOT make them ahead of time and store them for later use.

So, for those who subscribe to the theory that there was a bad run of heads and the problem has been corrected, I'm afraid that is probably not the case. Why would the problem vehicles have such a huge range of build dates if there was just a bad run of heads at some point in time?

I suspect that the heads are being manufactured to specifications and that the specifications are the problem, i.e., a bad design. Why else would the problem continue over all those months?

I HOPE I AM WRONG! Someone, please, prove me wrong! Please!

Tomster
I agree with what you're saying but....In January Chrysler produced its millionth Pentastar engine, are they a million Chrysler's on the road in January with this engine in it? If so great, if not there are a lot of cars that will have issues if in fact it is a design flaw. Actually either way there will be a lot of vehicles with issues. The silence is sickening.
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Old 06-16-2012, 08:22 AM   #1225
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I agree with what you're saying but....In January Chrysler produced its millionth Pentastar engine, are they a million Chrysler's on the road in January with this engine in it? If so great, if not there are a lot of cars that will have issues if in fact it is a design flaw. Actually either way there will be a lot of vehicles with issues. The silence is sickening.

Maybe I mean they are used in all these vehicles.
2011–present Chrysler 200
2011–present Chrysler 300
2011–present Chrysler Town & Country
2011–present Dodge Avenger
2011–present Dodge Challenger
2011–present Dodge Charger
2011–present Dodge Durango
2011–present Dodge Grand Caravan
2011–present Dodge Journey
2011–present Jeep Grand Cherokee
2011–present Volkswagen Routan
2012–present Fiat Freemont
2012–present Jeep Wrangler
2012–present Lancia Flavia
2012–present Lancia Thema
2012–present Ram Cargo Van
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Old 06-16-2012, 09:16 AM   #1226
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Maybe I mean they are used in all these vehicles.
2011–present Chrysler 200
2011–present Chrysler 300
2011–present Chrysler Town & Country
2011–present Dodge Avenger
2011–present Dodge Challenger
2011–present Dodge Charger
2011–present Dodge Durango
2011–present Dodge Grand Caravan
2011–present Dodge Journey
2011–present Jeep Grand Cherokee
2011–present Volkswagen Routan
2012–present Fiat Freemont
2012–present Jeep Wrangler
2012–present Lancia Flavia
2012–present Lancia Thema
2012–present Ram Cargo Van
I realize that, the question is are there 1,000,000 of them as of January 2012 on the road? If there are then a correction to the problem once found going forward is good for future buyers. I remember GM having problems with Cadillac engines wiping cams I think. That problem lasted years. Ford had problems too that lasted years, with a little time I can try and remember which engines and vehicles. I'm sure a resident car buff could help me out.
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Old 06-16-2012, 09:49 AM   #1227
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First thing I admit is I do not have the tick (yet? hopefully never) on my 12 JKU pentastar. I was under the jeep looking at a beautiful new skid mark & thinking about the exhaust on the drivers side.
I want to throw out a theory (just a theory mind you) about the lifter failure.

Could there possibly be a connection between the "interesting" pipe geometry between the CAT & exhaust 'Y' along with the VVT possibly only being associated with the driver's side cylinder bank since #2 lifter appears to be the problem? Is the #2 lifter the closest lifter to the shortest pipe that flows from the head to the CAT? I will not disassemble it to find out.

Where I am going with that is thermal transfer from the CAT to the head via the path of least thermal resistance (center pipe) because of more back-pressure / temperature from the exhaust loop. From basic fluid mechanics : as velocity goes down, pressure / temps go up.

Again, just a thought & I honestly know little about the exact implementation of the VVT firing patterns so take that with a block of salt.
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Old 06-16-2012, 12:41 PM   #1228
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If it is a heat thing what happens when we hit 100 degree temps this summer? Are we going to see more issues?

Something else to keep in mind is:

1) the location in the country (and world) where these are failing and is there a connection to weather temperatures

2) and under what kind of driving conditions are failures happening. Are these engines driven often under load in mountainous areas, heavy interstate use, or in heavy rush-hour traffic conditions. Any of those kinds of conditions can be hard on an engine.

I know I don't think I have a major tick, although it does sound slightly louder than it did a few months ago, but I also have not driven it under hard conditions above.
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Old 06-16-2012, 02:27 PM   #1229
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Well, my August-build 2012 now has a little over 13,000 miles on it. Some comments:

1) There is a very light tick when the engine is cold. It goes away when the engine warms up.
2) The engine appears *very* sensitive to oil viscosity. It wants an oil that's on the thicker side of the 5W30 spec or it is somewhat noisy. When I put Pennzoil Ultra 5W30 in it, I got a light ticking even when the engine was warm until I had around 2,000 miles on the oil and it started thickening up (like most synthetics the Pennzoil uses pour point depressants rather than viscosity improvers, and thus as it wears it gets thicker rather than thinner). Going back to Pennzoil Platinum 5W30 on the next oil change and the engine was no noisier when I got it back than when I took it in to the dealer for the oil change. (I'm having the dealer do my oil changes so there's no question about who is responsible if this turns out to be a problem, they have an "express line" for oil changes while you wait so that's not particularly inconvenient, but I *am* providing 6 quarts of my own oil because I don't want whatever crud is in their vat).
3) It's pretty clear at this point that build date isn't an issue, since my early 2012 Wrangler doesn't have the problem. It appears to be a head supplier issue that crops up seemingly at random where heads that shouldn't have passed QC due to casting flaws (these are thinwall aluminum castings which means that porosity is always an issue) are passed. The nature of the casting flaws is the only thing that is baffling, porosity is the only kind of casting issue that happens randomly as vs. due to a flaw in the mold yet it shouldn't cause this kind of issue unless it causes exhaust gases to get somewhere they're not supposed to be...
4) The heat hypothesis doesn't hold water. *All* Pentastars would have the problem if that was the problem.
5) Regarding head castings, they appear to be identical on all Pentastar engines, whether Wrangler or not. I looked at the change in how the alternator is mounted on the Wrangler vs. how it is mounted on other Pentastars, and it turns out that all the bracket mounts are on the engine front casting, not on the head casting, and the 2011 model Pentastars already had the holes there that the alternator is mounted to in the Wrangler, those are the top mounting bolt holes for the front casting but it is clear they already had provisions to mount something to them (i.e., there was already a wide surface to use for mating with a bolt-on accessory).
6) They really do have over 1,000,000 Pentastar engines on the road now. Remember, Chrysler sells over 500,000 minivans per year, minivans are their true bread-and-butter (they sell about as many minivans as they sell of all Jeep models total), and the Pentastar has been the standard (and only) engine in their minivans since last year.

In short, if there is a widespread head problem it should affect all of Chrysler's vehicles that use the Pentastar, not just the Wrangler, because the heads are identical across all of them. There's probably 1.5 million Pentastars on the road right now and we'd start seeing the problem in Chrysler's bottom line (a rise in warranty claim costs on their required SEC filings) if the problem was more than a casting quality control issue with a certain supplier where certain castings are passed when they shouldn't be. Note that heads are currently the gating factor for Chrysler ramping up Pentastar production -- they were going to make heads at Saltillo but the Mexicans couldn't do it with sufficient quality so they're operating with less capacity than they really need until production can ramp up at Trenton North. So it is unlikely that you're seeing stockpiled heads making it onto current build Wranglers, they are likely heads that were built within a month of the Wrangler being built, because that's how short the pipeline really is. But this also explains why heads that shouldn't pass QC may have passed QC, because of the pressure to make more heads given the fact that they're in short supply...
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Old 06-16-2012, 02:41 PM   #1230
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Join Date: Mar 2012
Location: western KY
Posts: 285
Well, Peeps, I wish all of you the best with your Pentastars but I will not have to worry about mine anymore. I traded my three month old JK Sport for a Toyota Camry today.

Mine was not ticking but it only had 3600 miles on it. I just wasn't happy with a Jeep for my daily driver and the fear of a future head problem was kind of like the straw that broke the camel's back. I was afraid that this head thing was a design problem and that if it was, and if the word got out, the resale value would be next to nothing.

I am probably just being paranoid, but like I said, I wasn't really a happy camper with a Jeep for my daily driver anyway.

Tomster

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