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Is the hood on the WK2 not aluminum? My WK has an aluminum hood?
It's an aluminum hood, but some folks have experienced corrosion. It often gets referred to as "rust" because many folks don't realize it's aluminum.
 

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Discussion Starter #42
Never had a vehicle with so have never used auto temperature control but i tried it out the other day on my TH.
After i enabled it, i looked at the climate page and none of the vent options there were hi-lighted! WTF!
After more poking around, the defrost vent somehow got hi-lighted for some unknown reason to me.
Is this all normal?

Looked at the Owner's manual and the only thing i got was its automatic, leave it alone and trust it. H'mm!
 

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Huh ... didn't even know there was a climate page. Now I guess I'll have to look at it and worry about what it says. Dang.
 

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Never had a vehicle with so have never used auto temperature control but i tried it out the other day on my TH.
After i enabled it, i looked at the climate page and none of the vent options there were hi-lighted! WTF!
After more poking around, the defrost vent somehow got hi-lighted for some unknown reason to me.
Is this all normal?

Looked at the Owner's manual and the only thing i got was its automatic, leave it alone and trust it. H'mm!
I think that's normal, that when it's on auto it doesn't show what vent options it has selected. Similar to how it deals with recirc control on auto, it will use or not use recirc but it doesn't turn the light on the button on or off with the changes. Most people never pay attention and changing lights would disturb the average person so that's how it's set up. It's similar to how many cars operate the dash "gauges".... The computer reads the sensor and the computer runs the gauge and the needle never moves unless the change is high enough to be "out of range". At least the jeep temp gauge actually moves.
 

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Hey Bubba, have you seriously never hit the climate button on the bottom of the uconnect screen????

219651
 

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Discussion Starter #47
I think that's normal, that when it's on auto it doesn't show what vent options it has selected. Similar to how it deals with recirc control on auto, it will use or not use recirc but it doesn't turn the light on the button on or off with the changes. Most people never pay attention and changing lights would disturb the average person so that's how it's set up. It's similar to how many cars operate the dash "gauges".... The computer reads the sensor and the computer runs the gauge and the needle never moves unless the change is high enough to be "out of range". At least the jeep temp gauge actually moves.
You're likely correct.
I agree with the idiot analog gauges also as my F150 uses that scenario also.

If its in auto, i'd like to see exactly what its doing.
For example why would the defrost vent be highlighted in the climate page.
It was a rainy day when i tried it out, maybe it detected fog on the windshield somehow though i didn't notice any fog on the windshield. I did have the auto wipers enabled that day.

In an attempt to control temps, i suspect the auto system kicks in the air conditioner (needlessly?) whenever it feels like it driving gas mileage towards the gutter.... where just lowering a window would suffice in most situations.

For the time being at least, think i'll stick with my old school method of controlling cabin temperatures manually.
 

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It is possible the Tach lags the actual RPM, but you should see the needle go above 6k after the shift, it lagging the rpm dropping...
What is the actual redline for the vehicle, where on the tach does it turn red?
I would guess it does. Not uncommon, although digital gauges should be much better than analog.

What happens if you go full throttle in 1 and just keep your foot down and don't shift? Does the rev limiter kick in and just let you run along at 6k? Or does it still bog somehow because you're trying to give it full throttle at or beyond redline? (No, I don't want to try this for myself to find out. You do it.)
It bounces off the limiter...LOL. Ask me how I know.
My WK1 SRT, in manual shift mode, will run to the redline and then shift to the next gear. When I test drove the Trailhawk, I didn’t know it didn’t behave the same way and bounced it off the limiter. Scared the $hit outta me!
 

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By "bounce off the limiter" do you mean run to 6k and then rev back a bit, thus perhaps producing the "bog" some have described? I think I did that coming off a light once having forgot I had it in M, and was so flustered by it I almost panicked. :oops:

p.s. So your SRT basically overrides the M and shifts automatically? That's interesting. And surprising. Do current SRTs behave similarly?
 

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Discussion Starter #51
OK found something else new regarding the V6 in my TrailHawk.
While waiting for my 3rd free oil change at the dealership i was looking through the Cherokee sales brochure.
Then my trusted tech there walked by and we got to talking about V6 engines.

I asked him why the Cherokee V6 was rated at less HP then my GC TH V6.
One thing he mentioned is in addition to variable valve timing, the GC V6 also has variable valve 'lift'.

He explained how it works but since forgot the whole explanation.
Seem to remember something about dual cam lobes/ cylinder/ valve?
Curious if anyone here knows in detail how this exactly works.
 

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By "bounce off the limiter" do you mean run to 6k and then rev back a bit, thus perhaps producing the "bog" some have described? I think I did that coming off a light once having forgot I had it in M, and was so flustered by it I almost panicked. :oops:

p.s. So your SRT basically overrides the M and shifts automatically? That's interesting. And surprising. Do current SRTs behave similarly?
Exactly. I don't remember at what rpm it actually hit the limiter, but it stuttered a bit before I shifted and all was good.

It kinda overrides it, but that's how it's designed. It runs up to the redline and then goes to the next gear automatically. I don't know if the WK2 SRT's behave in the same manner or not. The Mopar TCM that's available for the WK1's works like our WK2's do now. It runs to the redline and stays there w/I shifting.
 

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....I asked him why the Cherokee V6 was rated at less HP then my GC TH V6.
One thing he mentioned is in addition to variable valve timing, the GC V6 also has variable valve 'lift'.

He explained how it works but since forgot the whole explanation.
Seem to remember something about dual cam lobes/ cylinder/ valve?
Curious if anyone here knows in detail how this exactly works.
Variable Valve Lift? Or Variable Valve Overlap? or Variable Valve Duration?

On a typical DOHC, changing the timing differently on the cams will change the valve overlap, that could easily be done with VVT on a DOHC engine.... ...it would provide improvements in power, emissions and even smoothness at idle....

On a not so typical DOHC, where the intake and exhaust valves were on the same cam, being catty-corner of each other in the cylinder head, making porting very complex, you could vary overall valve duration by changing the cam timing, I doubt this is in the 3.6L, it would be very complex....

The only way I can imagine varying valve lift is adding additional parts and multiple levers to the valvetrain and photos I've seen of the engine with the valvecovers off those things aren't in there.... ...the only otherway might be a system to allow lifters/lash adjusters to collapse, but that would be inviting engine rebuild disasters, that the manufacturer has to cover under warranty....

Not saying it doesn't vary Valve Lift, I'm saying I can't understand how and wonder why what ever innovation they came up with to do that, why it isn't bigger news that more people know.....

BMW did have an engine years ago that was variable valve duration and lift, it was a series of levers for the rockers between the cam and valves. Basically reducing cam duration and lift to zero to anywhere in between to the full lift and duration the cam was capable of. The engine didn't have a throttle body, there was no reason to create a vacuum to reduce the engine power, simply dial down the cam duration and lift to the point the engine at full power would just idle, then adjust for partial power or full power....... I'm sure the engine didn't make enough vacuum to power the brake booster, and the diesel does have a vacuum motor, does the V6????
 

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Discussion Starter #54 (Edited)
Mongo,
the tech used the word lift and i think dual cam lobes which is why is i was surprised and baffled being around, maintaining and rebuilding engines over the last bunch of decades.

Sounds like mission improbable to me to accomplish that but then again the modern internal combustion engine is a far cry from the earliest engines.
Today's internal combustion engine i think has just about reached its peak for efficiency and the HP:displacement ratio. But who knows what future IC engine improvements are to come.
After checking out Google, to my amazement variable lift (vvl) technology is a reality.

Guess sometimes you can at least show this old dog new tricks. lol

Form wikipedia:
Fiat Chrysler Automobiles
Fiat Chrysler Automobiles added two-stage valve lift (VVL) to the 2016 update of its Pentastar engine along with improvements to its variable valve timing (VVT) system.

.....Fiat was the first auto manufacturer to patent a functional automotive variable valve timing system which included variable lift. Developed by Giovanni Torazza in the late 1960s, the system used hydraulic pressure to vary the fulcrum of the cam followers (US Patent 3,641,988).[1] The hydraulic pressure changed according to engine speed and intake pressure.....

Here's a Pentastar video which gives a clue, note the cam lobes.

The article also mentioned the latest Pentastars have an 11.3 compression ratio!
Gonna try premium gas next fill up and see if it makes any difference.
 

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VTEC is actually variable lift and timing. I believe the oil pressure causes a different set of arms to actuate the valve further at higher RPMs.

I have to wonder if the dude @moparado was chatting with was confused with the tigershark engine that has electronic intake valves that can open and close at any time and as much and as little as necessary. The Cherokee V6 is less HP because it's a 3.2 V6 and the GC is a 3.6. Otherwise they're identical.
 

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Today's internal combustion engine i think has just about reached its peak for efficiency and the HP:displacement ratio. But who knows what future IC engine improvements are to come.
Yea, but its climbed from about 30% to 40%, there is still a lot of energy going out of the exhaust pipe....
They are experimenting with 5 cycle engines and other innovations that can exact even more energy from the fuel.....
Mongo,
the tech used the word lift and i think dual cam lobes which is why is i was surprised and baffled being around, maintaining and rebuilding engines over the last bunch of decades.

Sounds like mission improbable to me to accomplish that but then again the modern internal combustion engine is a far cry from the earliest engines.

After checking out Google, to my amazement variable lift (vvl) technology is a reality.

Guess sometimes you can at least show this old dog new tricks. lol

Form wikipedia:
Fiat Chrysler Automobiles
Fiat Chrysler Automobiles added two-stage valve lift (VVL) to the 2016 update of its Pentastar engine along with improvements to its variable valve timing (VVT) system.

.....Fiat was the first auto manufacturer to patent a functional automotive variable valve timing system which included variable lift. Developed by Giovanni Torazza in the late 1960s, the system used hydraulic pressure to vary the fulcrum of the cam followers (US Patent 3,641,988).[1] The hydraulic pressure changed according to engine speed and intake pressure.....

Here's a Pentastar video which gives a clue, note the cam lobes.

The article also mentioned the latest Pentastars have an 11.3 compression ratio!
Gonna try premium gas next fill up and see if it makes any difference.
The article seems to imply this has been added to the 3.6L in 2016. That might explain why the photo I went back and looked at for the 3.6L valvetrain doesn't show those cams and rocker/follower arms.... ...it is different from some of the devices I have seen and talked about, but seems to work just as well....

And it does appear there are dual cam profiles that might be a big advantage over just fiddling with geometry to take some lift and duration out of the motion..... ....and it could be more reliable, moving a ramp up and down on a follower/rocker would be less likely to fail in a way to do damage then say collapsing lifters/lash adjusters...

And it does appear that the high lift section of the lifter does not have a roller, so its similar to flat tappet when oil has had the zinc and phosphorous compounds reduced because all engines, and I see posts about V6's having rollers and cam lobe damage that needs to be fixed...

Now it is making sense why the V6 has an electric driven power steering pump and (I think) an electric driven vacuum pump, as so does the diesel..... ....and those have been on there since 2011 (only the first part of the model year 2011 did the V6's not have these.... ....so maybe this came on a lot earlier than I assumed and must have looked at pics of other versions of the V6 or even earlier than that....
 

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Discussion Starter #57
VTEC is actually variable lift and timing. I believe the oil pressure causes a different set of arms to actuate the valve further at higher RPMs.

I have to wonder if the dude @moparado was chatting with was confused with the tigershark engine that has electronic intake valves that can open and close at any time and as much and as little as necessary. The Cherokee V6 is less HP because it's a 3.2 V6 and the GC is a 3.6. Otherwise they're identical.
The tiger shark engine is a 4 cylinder which i understand includes VVT and VVL, a big improvement over the previous anemic 4 cyl engine so called the 'world engine' i had in my old '14 Patriot.

The tech actually grabbed the Cherokee sales brochure i was looking at to verify the difference of around 25 more HP for the GC V6 engine vs. the V6 Cherokee before his explanation.

I looked at the Jeep page and all i could dig up there is the 3.2 V6 is VVT with no mention of VVL.
I would think if it had variable valve lift that would be a selling point in the sales brochure.
I highly doubt just .4 liters alone more displacement with the 3.6 V6 could account for 25 more HP.
 

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I've had my GC just about a year now and when backing out of my garage like i've done dozens of times before i discovered something new today.

Namely when the Jeep is put in reverse, the side view mirrors tilt down lower to view the rear wheel area.
Put it back in drive and the mirrors tilt back up to normal driving mode.
Cool.

Probably to make sure while backing up the family dog is not behind the rear wheels or the any other obstructions.
Unexpected find: When you pull the small storage cubby out of it's placement on the driver's side of the cargo area you will see a small steel cable with a finger loop at the end of it. This is an emergency release for the the gas cap lid.
 

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Discussion Starter #59
Unexpected find: When you pull the small storage cubby out of it's placement on the driver's side of the cargo area you will see a small steel cable with a finger loop at the end of it. This is an emergency release for the the gas cap lid.
Excellent find!

This like a million other things is probably hidden in the Owner's Manual somewhere but who has time to read that entire encyclopedia of a manual let alone 100% retain all that info to memory.
Sometimes i can't remember what i had for breakfast.
 
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