Design or engineering flaw = sooner or later all builds prior to July 2012 will be affected.

Manufacturing defect = only the heads manufactured in Mexico will pop up with the tick and need replacing...

 

Sab you've been quick slam the Mexican motors, do you have proof that they are the issue? Are all heads made in the same plant? I thought a supplier made the heads. My guess is a large batch went through with poor metallurgy.

 

Do you people ever fully read these threads? Hydraulic actuated valve trains DO NOT TIC AT ALL, if they are normal, period; end of story!!

 

They could have been redesigned with a better tolerance call-out on the print to prevent poor machining, such as hole runout or perpendicularity. Either way we'll never know.

 

From Pentastars - advanced V6 engines from Chrysler (and Mercedes)

October 14, 2011 update
Sources say that thousands of engines, including over 500 which were recalled, were built in Mexico using improperly maintained equipment; these engines are being repaired or replaced entirely. This is said to be the reason for shutting down the Windsor minivan plant despite a backlog of orders. The former head of Chrysler Mexico was dismissed shortly after this. This does show that Chrysler cares enough about quality to stop those engines from reaching customers, at great cost. It might also tip the balance to install a new engine assembly line at Trenton North; a cam line was already installed there after a Mexican supplier was unable to provide the needed quantities.

March 27, 2011 update
Direct injection 3.2 liter engine production is reportedly coming close, and should be centered in Trenton, with Mexico producing most of the 3.6 liter engines. The 3.2 is planned as a more economical variant for many vehicles, and possibly the only Liberty V6. It appears that each plant will run both engines.
We will start running pre production parts shortly. I am not sure when actual production will launch but but the build ratio will be 80% of the 3.2s are to be built at Trenton with 80% of the 3.6 in Satillo. We are going to start stock piling some crankshafts this weekend so that we have them to use when the two new machines are being installed in the rough end of the crankshaft line, probably by May.

 

No what I'm referring to the the vacuum effect created in the tubes of an exhaust manifold as gases come together in the collector. Because of the speed of the hot air coming out and traveling out the back it creates a vacuum in the the tubes coming out off the exhaust ports. So then when the exhaust valve opens, it helps empty the cylinder of the exhaust gas. I know this is usually important in high rev engines so it might not be all that important to the Pentastar engines. But with the exhaust ports so close to each other I would think it could get a little constipated, especially at higher RPM's.

 

Is that one of the reasons they're trying so hard to get us to shift at lower RPM's? The tach is green between 1-3k and that's when the ECO light comes on. However, I get much more out of my engine from 3-4k. Could that be one of the special conditions that cause the heads/lifters to warp...from constipation...lol.

 

No, that is where the best gas mileage is at in that green zone.

 

No that's the EPA thing. They are trying to help you with your MPG. I see a big difference when I'm out of the green, my MPG do drop big time.


And lifters won't warp. Not sure of the reason behind the swapping of lifters, unless they had different specs to compensate for something else. And I'm still a little confused as to this "head warping" symptom. I would have thought that the warp would create separation from the block, thus inducing fluid leakage. But not heard of anything like that yet. So the only thing I can think of is the valve guides in the head are dropping, or maybe even squeezing the valve stem creating the ticking noise by keeping the valve events open to long.

 

Hey guys, I know I'm a girl, but I'm a Jeep girl and that was a joke. I grew up with muscle cars and could change the oll and spark plugs (and check the gap) in a vehicle by the time I was 10.

So, you mean my Jk doesn't need prunes? See...another Joke.