Greetings to all,

I've been following this forum for awhile now and decided to jump on in. My wife purchased an 05 CRD. She had only one minor problem that was corrected with a software flash when she initially purchased the CRD. The 05 now has 20K miles on it and other than a mild shuddering about 52 mph (which has only shown up recently) there have been no problems. Mileage has been typically 22-23 city and 28-30 highway. As a result I purchased a 06 liberty CRD. Needless to say my experience has not been as good as hers.

I calculated the first tank of diesel on the 06 and got 26 mpg in a mix of city/highway. However, when my 06 showed the same minor problem that the 05 had I took the 06 in for the software update. Not realizing that DC was changing the software on a weekly basis, I've been dissatisfied ever since. Who in their right mind sets a shif point or TC lockup at 64 mph? I've had F1 thru F100000 done so far (including F37). Needless to say after F37 the 06 feels more like a gasser than a diesel. The transmission response does seem to be slightly improved, but the shifts points never changed. The biggest problem that I have with the 06 is the mpg. After the software updates started the mpg have never been the same.

I noticed that my mpg had dropped down to 20 mpg. So I started tracking my mileage, and noticed that it would stay in the range of 20-22 mpg. To get even a better picture I started tracking how much city mileage and highway mileage was going on each tank. I noticed a pattern develop that regardless of whether the mileage was a 30/70 city/hwy or 70/30 city/hwy the mileage always stayed in the range of 20-22 mpg. I did have 2 tanks where the mileage jumped to 29 mpg but the next tank would go back down to the 20-22 mpg range. The only thing that I've tried that would yield any improvement was to remove the intake tube between the front grill and the air box. That would give me about 1-2 mpg improvement. I have cleaned the boost sensor and no improvement has been noted. I believe there is something wrong but I can't figure it out. Any suggestions?

Needless to say, Untill I can figure out the mileage problem, the 05 will not be going in for F37. I want to see what develops with an after market torque converter as talked about is some of the threads in this forum. Also, does any one know if when the engine is off, does the 24000 psi pressure remain in the common rail or is it bled off?

By the way, for those that have had any software flashes, check that your cruise control still works. After the F37 for the 06, my cruise control did not work. Apparently during the flash, the computer lost the pinion factor. The dealer was able to put the factor back in and cruise works.

Thanks

i've had a drop in mileage also, from 26/27mpg to around 20 which i am attributing to winterized diesel. I have not had the F37 done and still had the drop in mileage. It just so happened that winterized diesel started coming out right when DC announced the F37 so I would say hang in there until Spring and see what happens...i expect my mileage to come back

Check for air in your fuel filter. This is easily done by pushing the priming plunger several times. If it is easy to push at first, then firms up, you have air. Open the bleeder screw and see if you get a spurt of air. There are several threads here that have pictures and procedures cut directly from the service manual. I never got better than 22 MPG in 9000 miles until I started to bleed the air from the system daily. The MPG shot up to 26 and the bucking went away. The jump in mileage coincided with winter fuel so don't be too quick to blame that. Mileage should drop off 5-10% not 20-25% with winter fuel.

Air bubbles mixed in the fuel will throw off the metering of fuel. It will also cause bucking after a high fuel demand situation i.e. mashing on the pedal to get onto a highway. Suction feed fuel systems are notorious for having air leak problems that are very hard to fix. Guess how our Jeeps feed fuel?

My Jeep has been in the shop for some 55 days, unfixed, for air in the fuel. They have replaced the filter housing and tank pick up so far. Now they are waiting on new fuel lines. A Lemon Law lawyer is in my future.

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2006 Liberty CRD-SOLD
Dynomax 2.5 exhaust

I have to agree with the winterized fuel and cold temps as a probable culprit. I experience a 10-15% drop in mpg with the winter fuel AND cold temps both last winter and this winter in my '05. In fact, it may actually be the cold temps reducing the effeceincy of the diesel more than the winter fuel, but the blended fuel does have less energy (BTUs) than summer fuel.
I have not really watched it that closely, but the colder the weather, the worse the mpg. Just this past week, we had some very cold temps and my hi-way dropped to about 21 which is very very low for me. Most of the winter has been warm by NE standards so the mpg did not drop much below 23.

any links on how to get the air out of the fuel line?

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2005 CRD Sport
Mods: Glasspack, OME HD Struts & Springs, 2" Daystar lift,
255/70/16 General Grabber AT2's on MOAB's
ORM&EHM with great success!
TJM T17 Bumper, 50W KC HID's

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2006 Liberty CRD-SOLD
Dynomax 2.5 exhaust

Cleaning the boost sensor gave me 2-3mpg avg.

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2006 Libery Sport CRD, Lt Kakhi, nicely equipped
*****GDE Hot Tune at 38,879 miles
*****Stock TC.....for the time being!!

Cold weather causes Charged Air Cooled diesels to use much more fuel because it is possible to over-cool charged air. The computer then compensates by running rich in an attempt to keep engine temps up. This is a well known issue in the bus industry which has made adjustments by adding clutches to CAC & radiator fans and shutters over the intercooler & radiators. A possible solution would be using a winter front.

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2005 Liberty Sport CRD, Lt Khaki, sunroof

Thankful to now be an EX-CRD owner.

My 06 has always locked up at 65 MPH and I have never got better than 23-24 MPH even all freeway. I guess Mine came from the factory with the same software you guys are getting now. BTW, mine is not listed for the F-37 //build date Feb-06

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Feb/2006 Silver Sport 4x4 CRD

My highway mileage is about 22-23 and city is 14-15...I just dropped in on the dealer that I originally bought the Jeep from and told them that my mileage was excessive. The service manager asked "how excessive"? Seeing tas there were serveral customers in the Service Dept., I said in a clear loud voice, "excessive as in, my Liberty gets worse mileage than my neighbour's 4-ton 6.0 litre Powerstroke diesel Excursion! So excessive, that my vehicle fails to comply with the Government's Vehicle Certification." Blanks stares for a moment, and only crickets chirping could be heard. They'll be hooking me up with a courtesy car and taking a look at it.

The service manager first told me that the EVIC is not overly precise. I told him that not withstanding his views about the accuracy of the EVIC's mpg readout, I don't have an EVIC -- I compatre tripmeter against qty fuelled, always to the same place in the fill tube, the nozzle splash guard. He replied, "Oh..." More silence...

I fully agree about the ridiculous mapping of the transmission shift and lock-up point! 52mph for 4th(5th) lock-up and 63-64 for 5th(6th)??? I think my city mileage would be a lot better if the transmission actually used more than the first three gears. I have actually been driving with O/D off and at least get lock-up in 3rd, which actually results in lower rpm than a shift to 4th and the wonderfully slushy new F37 TC letting the engine turn valuable work energy into heat...no wonder the CRD warms up so quickly, even in the winter; the waste heat from the inefficient/slipping TC warms the main radiator, thus warming the engine... If I were boss for a day, I'd bring 4th down to around 45mph lock-up, release at 40mph or 2/3 throttle (vice full throttle currently), and bring 5th down to 55mph lock-up releasing at about 50mph or full throttle.

I'm sure the lower gears wouldn't be a problem as much if the stall was in the 1200-1500rpm range, but it isn't...

Duey

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2K9 Space Grey 335d Sport
2K1 Galaxy Blue Jetta TDI 5-sp

Thanks to all that have replied. This is a great forum. I did go check for air and behold after pushing the primer button 20 times and opening the bleed valve, air came out. I have not had any noticeable engine problems, but then again I normally don't mash the pedal to the floor. Normally, I don't let the fuel level go below 1/4 tank. Would an air leak cause excessive smoke? So, I'll keep track and see if the air leak returns.

As for the winterized fuel, I would agree that fuel with a lower heat content (BTU's) would result in lower gas mileage. Just look at ethanol compared to gas. However, I have been tracking this problem since July of last year. So regardless of whether the outside temp is warm or freezing the mileage remains the same. No matter whether I drive all city or all highway, the mpg stay in a very small range 20-23 mpg. My wife's 05 crd will swing a lot further when driving all city versus all highway. She drives 80% city and always gets between 21-23 mpg. I've driven the 05 where the mileage was 35% city and the mileage went to 30 mpg. I have spoke to the service manager and he agrees that there is a problem but they have been unable to determine anything. So
I'll have to figure it out for myself.

The build date on my 06 crd was Sep 05. So I think my jeep got off the production line with the old software like my wife's 05. Ever since I had the first flash on the 06, the transmission mapping has been ridiculous. Nothing like trying to use software to cover up a mechanical problem. Why jeep could not call MB to solve the problem instead of letting their incompetence shine throug is beyond me. Since I the 05 is pre F37 and the 06 is post F37 I will probalby do a brake stall test to see what the stall speed is between the two. I'll let you know what I find out. Has any one considered sueing Jeep for the original software
and fixing the TC problem on their own?

If I were the boss for a day I would fire everyone (bean counters and management included) and get people from MB with diesel experience to solve the problem. Once I see an aftermarket TC suitable for the CRD, the 05 CRD will probably go into the crawdad OR. (Me as the surgeon).

Just for the heck of it, I did test drive the MB ML320 CDI. It is an awesome vehicle. The engine has just enough clatter to declare itself a diesel, but when you sit in the car, you hear absolutely no clatter. The 7 speed transmission shifts like a dream and has plenty of get up and go. Now if they would just do something about the price.

Ditto.

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Thanks,
Ken Jennings
2006 KJ Limited 4x4 CRD, Option Pkg G, Lt. Khaki, Built 1 Feb 2006
Tow Package for myself, EVIC TPM
Side Curtain Airbags for my daughter
http://www.kenjennings.cc/crd/dieselexp.html

I had my Magnum on a road trip last week and the speed limit was 55 mph with some 60 mph so I managed 31.7 mpg out of a 2 ton station wagon with poor aerodynamic's.

That is about the same as the best I ever got out of the CRD.

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91 MB 300D 2.5L Turbo. Her's

05 MB E320 CDI. Mine

That's pretty fast to read the headstone inscriptions

There is always a comedian in the bunch.

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91 MB 300D 2.5L Turbo. Her's

05 MB E320 CDI. Mine

I really like my liberty, I commute mostly and would love it more if I could get 28-30 out of it.........has there been Any feedback from the Inmotion guys about mileage?
The thing that bothers me is that after mine locks up at 65MPH it never unlocks all the way to work so a different TC or transmission tuning is not going to change my freeway mileage, the final drive is the same on all CRD's...........Computer tuning is the only thing that will help.

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Feb/2006 Silver Sport 4x4 CRD

I have to agree with you except that according to the reps from DC, the lock-up usually happens in 3rd gear at @ 35 mph. After that, upshifting happens in lock-up under most situations. An aftermarket TC with a lower stall speed won't do anything for your highway mileage and is virtually useless when overridden by the lock-up clutch. To improve mileage you would be best to concentrate on intake & exhaust constrictions, keeping CAC & emissions equipment clean and electronic engine tuning.

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2005 Liberty Sport CRD, Lt Khaki, sunroof

Thankful to now be an EX-CRD owner.

RF, if the lock-up happened in 3rd without having to have O/D selected off, then we'd see far greater efficiency in the 35-55mpg range. As it is now, I don't see lock-up uintil 53-55 mph...that doesn't ever happen in the city. There are a number of 60km/h-40mph streets in town that lock-up in third then upshift still locked to 4th would be nice to drive around.

I'm also trying to figure out if it's just my ears playing tricks on me, but it sounds like my tranny is actually shifting up through both 2nd's....starting off from a stop there is a clear time that the engine runs up through first, then second, then at the end of second, there is what sounds like the slightest reduction in engine speed (no easing up on the accelerator pedal) but with the feel of a shift, then a more positive shift into what is clearly 3rd....stays that way until the shift into 4th at around 45-48pmh and subsequent lock-up in 4th at 53-55mph....???

Duey

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2K9 Space Grey 335d Sport
2K1 Galaxy Blue Jetta TDI 5-sp

This style transmission is programmed similiar to big Allisons in many ways. The only way I could feel it was run the shifter lever one gear at a time and count the nudges. OD off = 3rd gear (1:1) which can be either locked or unlocked. You will feel the second nudge in 3rd @ 35 mph which is the lock-up, at least that is the way it was programmed in TSB 18-009-06. I complained about an erratic 2-3 upshift (35 mph event) to the DC's support reps last Spring. They were quick to respond that it was a sloppy TC lock-up and told me it would be fixed in the next software release (TSB 18-023-06).

They also explained the entire transmission control logic. IIRC this transmission can have lock-up programmed for any gear (2-5) depending on load and rate of acceleration. You can also get a drop-down unlock rather than a hard downshift under some conditions. The programming is all a trade-off, early lock-up mean better overall fuel economy at the expense driveability/zip. Frequent lock/un-lock to improve driveability is hard on the hardware (which is blowing out the clutches). I think the re-programming numbed down the sensitivity to help the equipment life.

I get the sense when reading a write-up, when someone says they get TC lock-up in 5 gear, then they were likely gettin' on it all the way to 60+. I feel this too when I bump the OD-off switch to get passing gear on the highway, sometimes feel the extra nudge in 4th or 5th but usually watching the smoke cloud more than the speed to know exactly.

What this package really needs is an Allison style shift pad including a dual shift mode program and the ability to selectively lock-out 5th gear. Once you can control the OD shifting, then bump the diff ratios to @ a 3.33 and then you might just see that 30 mpg on a regular basis.

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2005 Liberty Sport CRD, Lt Khaki, sunroof

Thankful to now be an EX-CRD owner.

My most recent tank has yielded the best millage yet! 80% highway driving and I averaged 26.11 mpg for the whole tank!

My worst milage has been 21 mpg.

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06.5 Jetta TDI PKG 2 - Silver/Anth