Loss of power on random days

[Daltong2000]

Just wondering if I should be worried. Some days when I drive my 05 KJ, it feels like it has no power at all compared to my fiance's 03 KJ. 3.7 V6. Other days it feels like it has the power hers has. Same gear ratios so that's not the issue. Like I said, some days it feels like it has 100 horsepower. other days it feels like factory. Suggestions? Cause for worry?

 

[LibertyTC]

When was the last time you did a tune up, Jeep likes new NGK plugs every 35K.
Is the engine smooth running, no major shake or misfire issues/ engine light on?
PCV clean ?
Rear diff fluid changed every 25K?
Any brake issues/dragging?

 

[Daltong2000]

When was the last time you did a tune up, Jeep likes new NGK plugs every 35K.
Is the engine smooth running, no major shake or misfire issues/ engine light on?
PCV clean ?
Rear diff fluid changed every 25K?
Any brake issues/dragging?

Jeep got new spark plugs about 50k miles ago I think. That's probably my issue. No check engine code. Not sure if PCV is clogged. I feel like I would be having more issues than what I am if the PCV was clogged. But just in case how do I check? Don't know if the rear diff fluid has EVER been changed. At least not in the 20k miles I've owned her. It was my mothers vehicle before I bought it from her. No weird brake drag or anything. stopping power is good. I need new pads in the next few months but no issues from that. Jeep runs somewhat smooth at idle. Doesn't shake horribly but theres a little bit of shake to it. Not very noticeable. mocked it up as my flowmaster that was welded in causing that. Given a custom exhaust did the same to my ole reliable Honda. Don't think its misfiring. But my gas mileage *****. 15 to the gallon at most. I'm still on stock size tires. 235/75r16. They're cooper discoverer rtx. the more aggressive tread pattern may account for .5 or at most 1mpg loss

 

[LibertyTC]

Ya plug gap is probably well worn by 50k for sure.
Jeep will run like a champ with these!

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I also get about 15 mpg hwy, But do replace the rear diff gear lube ASAP.
If you have a TRAC LOK you will need to add a 4 oz bottle of limited slip Additive to the gear lube. (friction modifier)
8.25 Corporate Rear Axle should use a SAE 75W-90 Gear Lubricant. For trailer towing, the lubricant should be replaced with SAE 75W-140
I use Lucas gear lube and a Lubelocker 8.25 gasket.
PCV remove the hose hot, use a hair dyer if necessary if it is on there tight..
After hose is removed..then go ahead & turn it counterclockwise.

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[ltd02]

When was the ****** serviced last? Not saying its the problem but given the other service unknowns, it would probably be good to do a simple pan drop service. If you don't know when it was done last then don't do a flush. That could do more harm than good.

 

[LibertyTC]

& then comes the front diff and transfer case, we will get your KJ in top shape yet ha ha..

 

[Daltong2000]

How would I know if I have selectrac?

 

[Daltong2000]

Trac Lok. Not selectrac. oops. Wasnt paying attention

 

[turblediesel]

Selectrac has 4 high (full time) and 4 low (part time) selections on the lever along with 2wd and neutral.

Command trac doesn't have the 4 high (full time) awd choice.

Hop I got that right.

 

[turblediesel]

Tracloc... find someplace that'll allow slippage and show tracks... do a little 2wd burnout, walk back and see if both wheels turned together after a little spinning.

Or it can be looked up by vin, a build sheet? At any rate, it's a good excuse for a burn out.

 

[Daltong2000]

Tracloc... find someplace that'll allow slippage and show tracks... do a little 2wd burnout, walk back and see if both wheels turned together after a little spinning.

Or it can be looked up by vin, a build sheet? At any rate, it's a good excuse for a burn out.

Looked up my build sheet via vin. Says I have command trac but no mention of traclok

 

[LibertyTC]

A Trac Loc with both rear wheels off the ground will turn both wheels in same direction. Open Carrier-one will spin opposite direction.
Try using this VIN decoder and look closely: https://www.youcanic.com/wiki/jeep-vin-decoder
A Trac Loc may still have the tag remaining and look from R side, from just under the rear door toward the rear axle..
Try looking at both L& R side for the sticker- as they may place it on either side?
You can call the dealer & give them you VIN # as well, they will confirm if you may have a trac-lok.

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Or Just use 75w-90 gear lube with limited slip additive built in, if you are not sure what you have...

 

[Daltong2000]

A Trac Loc with both rear wheels off the ground will turn both wheels in same direction. Open Carrier-one will spin opposite direction.
Try using this VIN decoder and look closely: https://www.youcanic.com/wiki/jeep-vin-decoder
A Trac Loc may still have the tag remaining and look from R side, from just under the rear door toward the rear axle..
Try looking at both L& R side for the sticker- as they may place it on either side?
You can call the dealer & give them you VIN # as well, they will confirm if you may have a trac-lok.

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Or Just use 75w-90 gear lube with limited slip additive built in, if you are not sure what you have...

Okay there is a sticker on the upper side of my rear axle about 6 inches from the wheel but I cannot see if it says traclok of not

 

[LibertyTC]

Call any local dealer & give them your VIN #, they will confirm if you have a trac-loc rear diff...
The dealer also sells the 4 oz bottle of Limited Slip Additive if you need it.
I just called the dealer the part number for the 4 oz bottle is: 04318060AD
This is the Mopar 4 oz bottle for reference, still seems to be a current part number.

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