I have a Ram 5.9 in my TJ. I've always gotten 11. Wheeling I'll get 8, it's terrible.

 

I dunno why but my mileage is back to where it used to be almost.. Im sitting at 12mpg on the overhead. and I have driven 80 miles on a quarter of a tank from full.. Im not at the half way mark yet. where prior it was at the half mark after only 110 miles..

Once its half a tank I'll fill it back up to get the actual mileage but my overhead is usually 100% accurate.. Anyway, I have no idea why it went from 9.9-10mpg back to 12... All I did was unplug the catch can and hook the pcv back up normally.. I did also replace that rotted out rubber line on the chacoal canister and i drained some oil outa the pan as it was about half a quart or so overfilled.

I really dont know... Its weird i know you all run catch cans but i sware mine lowerd my gas mileage... I might hook it back up after I refill the tank here soon and see if my mileage lowers again. I like having that thing hooked up it really does stop alot of oil from getting in the intake.. It was a quarter way filled up after only 700 miles.

 

Well, that's the way of troubleshooting. Hook it back up for your next tank, run it, see what happens.

 

Well a little update guys.. I drove my Jeep 110 (220 total) Miles on the freeway to a friends house 2 days ago.. I reset my overhead and watched and right as i was getting off the freeway and into his city my overhead was showing 18.3mpg.. This is while driving around 55-70mph.. Usually handing around 60-65mph i was getting good mileage.. 70mph and it would drop. (FYI besides driving to New jersey twice in 3 years my Jeep has always been a city driver) So Im sure the 200 mile trip helped clean that engine up some maybe since its not burning oil anymore.. I still cant believe how clean my tailpipe is now.. its like i can eat from it lol

On my way home It went down to 17.3mpg but there was a lot of traffic so it wasnt that much of a straight shot.. 230miles total i made it home with a lil less than half a tank. I think the second round tho used more gas because of the traffic. Since half a tank is about 12 gallons.. I guess my mileage is fine when it comes to the freeway or superb actually because im using BFG rugged terrain's 31 which arent that great on gas..

Still doesnt explain why my city mileage is so bad.. But hey i guess im just doing more short trips and stop and go then i used to do.. I was expecting only 15-16mpg driving up there but hey 18.3mpg was pretty damn impressive i got there 110 miles out with a quarter of a tank of gas.


On a side note.. I noticed my trans shifter and transfercase shifter area radiating alot of heat.. I dunno if i noticed this in the past but my leg started getting warm and so i felt the plastic area around the shifters and they were pretty warm starting to get hot.. The handle shafts were warm too the ***** were ok tho.. Is this normal for that that area to be radiating heat while driving 55-70mph for 2 hours ? I have an AUX cooler bypassed from the main radiator.. the check valve is stuck OPEN because i always have to put the tranny in neutral when i start the Jeep if i dont because its stuck open and the fluid drains out it will move when i step on the gas but it wont like it.. if i let it flow for a second or two its fine and moves on its own when i let off the brake. (i can even hear it filling up for those 2 seconds) I checked by unplugging the return line and it squirts lotsa atf out.. I havent checked that since i noticed this heat tho maybe i should.

But yea i realize the tranny and transfercase put off alot of heat when moving fast.. but still enough heat to radiate up through the console where the shifters are ? To me that means something is getting VERY hot.. because at those speeds youd figure the wind would keep it cool.. But maybe im being paranoid

 

Dont get a lot of airflow up around the trans..... and they DO get pretty warm. Probably wouldn't hurt to install a trans temp gauge, and see what is really going on. I would still dump the check valve.......

 

how tho ? do i just cut it off ?

 

If you've bypassed the factory cooler you've likely already deleted the check valve.

 

Well when I bought this thing the previous owner had the aux cooler installed and bypassed the main radiator.. Its a 22,000 gvw hayden cooler.. The check valve is on the hard line for the transmission right where the rubber lines connect and go into the cooler. Im not sure if he drilled out the check ball or something all I know is its either stuck open or drilled out because when the Jeep sits for a few hours the fluid drains out of the torque convertor or whatever.. If i start it up and drive it moves fine but itll act like it doesnt want too.. Well not want too but act like its low on fluid or something.. Then 2 seconds later its fine.. So what I do is put it into neutral to start the pump and then i can hear a whiring noise for a second or two and then if i let off the brakes itll roll backwords or foward without me needing to step on the gas..

Does this make sense ? So that tells me the check ball is stuck open or drilled out.. The problem is the checkvalve unit is still on the hard line.. So I dunno if its just stuck open or if its drilled out or what..

My check valve looks something like this one.. Im wondering if i should unplugg the rubber line and chop the thing off the line ? The only worry id have is if i put the rubber line back on after itll be on a smooth line.. ATM it has a barbed end to go in.. I'd be worried itll slip or blow off driving down the road.

 

Well, if it drains back into the cooler than the check ball has been drilled out. They don't stick open to my knowledge, when they stick, they stick with crap and don't allow the trans to get cooled oil.

 

Pull the hose. Have a look. No point in just guessing.