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Stock JK Tech Bulletin board forum regarding issues with OE (original equipment) components of the Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) such as factory suspension parts, engine, transmission, body parts, interior fixtures and the on-board computer.
View Poll Results: What's your odometer reading? Problems??
25,000
19.24%
50,000
24.95%
75,000
20.38%
100,000
14.76%
125,000
8.10%
150,000
7.43%
200,000
3.05%
250,000
1.33%
300,000
0.38%
350,000+ (please list if higher)
0.38%
Voters: 1050. You may not vote on this poll

This is a poll for the JK 3.8L V6 and it's engine longevity. Engine problems so far?

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Old Feb 16, 2017 | 09:42 AM
  #531  
Mr Burgundy's Avatar
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From: Toronto, Ontario
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07 sport with teraflex lift and 35's.
Light bars, smitybilt bumpers extra..

Even with the Dana 35 in the back havnt had any problems and just hit 110,000 km

Only complaint is the underpowered engine. But got a superchip and that helped a bit. Debating a cold air intake.

Love this jeep!
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Old Feb 19, 2017 | 07:19 AM
  #532  
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Joined: Jul 2012
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From: Glenwood Springs, CO
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Originally Posted by Mr Burgundy
07 sport with teraflex lift and 35's. Light bars, smitybilt bumpers extra.. Even with the Dana 35 in the back havnt had any problems and just hit 110,000 km Only complaint is the underpowered engine. But got a superchip and that helped a bit. Debating a cold air intake. Love this jeep!
I also have a Superchips. I added a CAI and loved it until I noticed a slight whistle at low rpms. Replaced the throttle body with a Viper TB and the whistle went away. Loving it even more.
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Old Feb 19, 2017 | 07:49 AM
  #533  
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Foo
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Joined: Mar 2007
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From: Phoenix, AZ
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Originally Posted by dawnm24
Main seal gasket replaced...Would not cover under warranty because I was a couple weeks late with my 5 year inspection. Didn't know it was leaking and had just had the oil changed.

Other than that just minor stuff.

Dawn
Ya was a couple weeks late 5 years ago, and they said I was SOL. that kind of sucks since I was moving, but on the plus said 10 years old and no real issues.
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Old Mar 10, 2017 | 06:52 PM
  #534  
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Joined: Sep 2016
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From: Toronto, Ontario
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Originally Posted by Fafafofi
I also have a Superchips. I added a CAI and loved it until I noticed a slight whistle at low rpms. Replaced the throttle body with a Viper TB and the whistle went away. Loving it even more.
After adding the CAI and a throttle body did you notice any improvement on mileage or hp?

I did some more research and I'm stuck now between doing the CAI + throttle body spacer or a good exhaust system.
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Old Mar 10, 2017 | 08:09 PM
  #535  
jtphoto JK's Avatar
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Joined: Apr 2008
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From: Thunder Bay, Ontario
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Both the CAI and throttle body spacer are a waste of money..

Throttle body spacers were only effective when fuel was injected at the throttle body BEFORE the spacer.

CAI under hood are not cold air they pull in hot engine bay air. Only a snorkel is a CAI.
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Old Mar 11, 2017 | 02:14 PM
  #536  
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Joined: Dec 2009
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From: Texas
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Originally Posted by jtphoto JK
Both the CAI and throttle body spacer are a waste of money.. Throttle body spacers were only effective when fuel was injected at the throttle body BEFORE the spacer. CAI under hood are not cold air they pull in hot engine bay air. Only a snorkel is a CAI.
Cold Air Intakes are designed to allow a higher air flow and smoother air flow into the engine (part of what the throttle body spacer helps with - the quality of air flow). All the ones I have seen use the stock air box location which draws cooler outside air in for combustion.

More and cooler available air with better flow characteristics allow the computer to increase the injection on time, allows for better cylinder filling and allows the fuel to better mix in the airstream. More fuel and air into the cylinder equals more power out at bang time.
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Old Mar 11, 2017 | 04:36 PM
  #537  
jtphoto JK's Avatar
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From: Thunder Bay, Ontario
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Originally Posted by zstairlessone
Cold Air Intakes are designed to allow a higher air flow and smoother air flow into the engine (part of what the throttle body spacer helps with - the quality of air flow). All the ones I have seen use the stock air box location which draws cooler outside air in for combustion. More and cooler available air with better flow characteristics allow the computer to increase the injection on time, allows for better cylinder filling and allows the fuel to better mix in the airstream. More fuel and air into the cylinder equals more power out at bang time.

If you do a search you will find data from fellas that have recorded actual air intake temperatures and found that the temps are much higher from the CAI.
The computer controls all air in and fuel. Your computer would require a custom tune to take advantage of any extra air the CAI could add.
As for the TB spacer, again that is old tech
designed to help atomize the fuel which can only be done if the fuel is injected before the spacers though a TB or carburetor. It does not benefit multiport injection in the least. If you want to see any kind of intake difference on the 3.8 you can add the 2008 Viper 74mm TB to replace the 58mm stock one.
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Old Mar 11, 2017 | 08:07 PM
  #538  
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A new intake with a filter isn't a CAI it's a new intake. The CAI will seal against the hood or have a whole air box that draws from either a snorkel or the factory outside air supply.

The computer measures throttle demand to determine how much air it needs, measures that air to determine how much fuel it needs and feeds the fuel into the air (yes, downstream of the throttle body), and applies spark. If it measures more air it will, up to the limits of the injectors, add more fuel as power is demanded so allowing more volume of denser air allows more fuel to be added producing more power.

I can't answer to all the fellas for what they have installed, nor for their testing methods or measurement accuracy. I can say that it is a simple equation, more air plus more fuel equals more force against the rod causing more rotational force on the crankshaft. If it isn't a well designed system and it isn't a CAI then it is what it is. Don't buy cheap.
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Old Mar 18, 2017 | 06:44 AM
  #539  
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Joined: May 2016
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From: Chelan Falls, WA
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136K miles. K&N Intake, Ripp long tube headers, better plug wires, Mobile 1 5W20 since the first oil change. Manual 2008 JKUR on Terraflex Pre-runner 4" and 35's.

Uses more than a liter between 6000 mile changes, starting to feel a little low on power. I need to do a compression check soon. Searching for other options (Hemi, new 3.8 long block, used 3.8, building this 3.8, adding a Ripp S/C, or the new Cummins)

The only issues I have had with this engine besides lack of power is a water pump at 6K miles and cracked exhaust manifolds at 80K. Driven HARD. I even towed with it for probably 20K miles, over mountains in the summer.
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Old Mar 19, 2017 | 06:07 AM
  #540  
jtphoto JK's Avatar
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From: Thunder Bay, Ontario
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Switching to 5w30 or 5w40 European blend will help with consumption.. if you are down on power it may be time to change plugs again.
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