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davidmay

Joined: 25/08/2009 05:53:00
Messages: 5
Location: Houston, TX
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Looking for advice for improvements for my new (used) 2006 Jeep Liberty CRD to improve operation, gas mileage, towability, and reliability. Granted, all of these goals together are rather "best of all possible worlds". Advice on how to achieve most of them would be appreciated. Discussion of trade-offs with also be appreciated.

I have read through most of the posts on this web site. So far, I would lean toward buying the Eco Performance Tune and an upgraded torque converter for now. However, any changes need to be pretty much invisible to the driver, i.e. they should not need someone to change their driving habits. The vehicle will be used by my wife to pull a 3000 lb trailer in the hills and mountains of the western US and I don't expect my wife to have to understand much more than "don't try to maintain 70 mph up the side of a steep mountain, it ain't gonna do it" type instructions (she's a very smart individual, just not an automotive engineer).

The Eco Performance Tune upgrade is a no-brainer, since that is Green Diesel Engineering's main product. The soon to be available turbo upgrade is interesting but too expensive right now (besides, I prefer others to work out the bugs in a new product -- I am very concerned about reliability, since my wife will be out in some very remote locations with the Jeep and the trailer).

There has been some discussion about torque converter upgrades. If I read the posts right, one recommended torque converter candidate is a European torque converter ("Euro torque converter from the new VMM 2.8"), another is I believe a OEM torque converter from a newer Jeep Liberty model ("JK converter from a 2008 or newer vehicle"). Is this correct?

Any specific information about these two torque converters would be appreciated (part numbers, manufacturers, places to order, etc.).

Also, any explanation as to how to evaluate a torque converter replacement for the 2006 Jeep Liberty CRD would be great. Thanks.
Lancer

Joined: 15/07/2009 02:30:43
Messages: 18
Location: London, England
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Hi David
The tcs you refer to are in fact the same unit. The Euro tc referred to is the tc from the European - specification 2.8 diesel engine fitted to the JK Wrangler sold over here. No-one with any sense here buys a petrol-engined 4wd of any size (ie excluding cars like the Suzuki Jimny) - the fuel consumption (given our fuel prices) is just too ridiculous. The exception of course is the very expensive luxury cars like V8 Range Rovers etc.

Another option that some have followed is to fit a Suncoast tc. See the various threads on LOST with people's how-tos and views on the Suncoast unit. The "Euro tc" part number is in a reply from GDE to one of my queries in this forum and is 68037142AA.

There is, in England, an 11 day waiting period to order this tc. As I don't believe that the JK is offered in the US with a diesel engine, I don't know if it's on offer there, or if this is the same tc that's fitted to US petrol JKs with auto boxes -perhaps an enquiry of your local Mopar dealer?

I am currently out of work, but once back, and with a bit of cash built up, I believe that turbo upgrade and flash would be a good investment in the vehicle. Most CRD owners seem to be in it for the long haul! Certainly, my wife and I envisage keeping it until it is either irreparable or destroyed


Light Khaki 2005 CRD Sport. TJM type 17 bumper, extended breathers, Grabber AT2s
GreenDieselEngineering
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Joined: 10/07/2009 07:25:47
Messages: 353
Location: Southeast Michigan
We intend on having reliability with the turbo kit...as for now, we are making trips with spare hardware just in case

We are planning a towing trip out west with a 3000-4000 lb. trailer with the turbo in early September. This will allow us to dial in all the safeties.

Have you noticed any drive ability issues with the KJ? The first trailer tow up a grade at 1700rpm in 3rd lock-up will let you know how strong your current TC is. If it shudders as you load the throttle to just below any downshift point, then you may want to push toward an upgrade. The ECO tune helps to minimize the initiation of shudder through torque management in lock-up, a good safety for the interim.

The ESP on the 06 model does very well in bad conditions in the mountains...is the vehicle already set-up with trailer brakes? A good investment if the vehicle will be towing often. The KJ can be a great long term vehicle...good purchase!
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davidmay

Joined: 25/08/2009 05:53:00
Messages: 5
Location: Houston, TX
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I have not towed a trailer yet. I have only had the vehicle for a week and (unfortunately) have to get one very serious safety problem fixed first. My first step is to actually determine what the problem is. Since you asked ( ), here is the issue I have at the moment (advice on what the real cause of the problem might be would be greatly appreciated)...

I just bought the 2006 Jeep Liberty CRD (used, of course). The odometer reads 44,000 miles. I don't know when the fuel filter was last changed, however it looks reasonably clean on the outside. My wife took the Jeep on a hiking trip to Big Bend National Park last week. On the way there, no problems. She also reported getting at least 32 mpg fuel efficiency. The speedometer seems to be reading too fast by about 5%, so the real economy is about 29 mpg. I am happy with the mileage. My wife usually takes our little Casita trailer with her on these trips but we have not had time to get the Jeep wired for pulling the trailer, nor does it have a hitch yet, so no trailer on this trip (she wanted to drive the new car). This turned out to be a blessing in disguise.

On her way back, there was a point where she went to pass an 18 wheeler on a two lane road with sparse traffic going both ways. She put the pedal to the floor and was about half past the 18 wheeler when the engine died. She ended up coasting off to the shoulder of the opposite side of the road with the engine dead. She was able to restart the engine after putting the car into park, and allowing a moment for her heart rate to subside, she calls me to tell me what happened. No engine check light came on at the time.

Later during the same drive back to home (and on the same day), the Jeep started losing power. The highway speed dropped to about 45 mph and the engine check light came on. She pulled off the road and called me on the cell. I said she would have to find a dealer to get the engine checked. She took off again. Now the engine seemed to drive fine (no problem reaching highway speeds, no lack of power). The engine check light was still on. An hour later, the engine lost power again. She pulled over, waited, took off, everything seemed fine. The engine check light is still on.

She was able to reach a Jeep dealer. The mechanic said the problem was lots (he said lots and lots) of air in the fuel filter. He bled the air out and charged us for a diagnostic service. He wouldn't tell us the trouble code that the car was reporting.

So now my wife is driving on I10 near San Antonio, TX, in majorly busy traffic. She says a car was pulling into traffic across multiple lanes from the on ramp, she went to speed up to stay out of the way (and no doubt to stay in front), and the engine dies again. Now she has to coast to the shoulder, crossing two lanes of traffic, with a dead engine. She gets to the shoulder safely, restarts the engine, and continues home. No engine check light came on at the time.

After she gets home, I check the air in the fuel filter again. There's maybe a few bubbles but not much. I then fill up the tank with diesel and head for the airport (I'm flying out of town). While on the way to the airport, I try a test. I start at 40 mph on flat ground and floor it. Just after I hit 80 mph, the diesel dies and I have to coast to the shoulder and put it in park before the engine will start. The good news (?) is that I did get a code P0093 (Fuel rail pressure malfunction positive pressure deviation). I have not had the chance yet to check the fuel filter for air (I will once I get back home).

If I find a lot of air then I might guess that the fuel system in leaking air into the filter during high fuel usage. However, there really wasn't any air in the fuel filter when I checked it after my wife got home, so I'm not convinced that air in the fuel line is the problem (no doubt it was when the engine lost power but the stall may be different). The P0093 code might be a symptom (abrupt shutoff of the engine producing a momentary spike in fuel line pressure due to fuel injectors slamming shut).

One question I have is: Is the ECM deliberately killing the engine for some reason? If it is then that seems to be an INCREDIBLY dangerous thing for it to be doing.

As for what problem the engine is having (whether or not the ECM is killing the engine), any ideas???
GreenDieselEngineering
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Joined: 10/07/2009 07:25:47
Messages: 353
Location: Southeast Michigan
This fueling issue has plagued several owners of the KJ CRD. These is not one specific cause, but rather system weaknesses that can add together to make the problem more pronounced. The P0093 occurs when the actual rail pressure cannot meet the desired set point for a certain time period. This flags a fault, causes limp-home mode and does not seem to recover unless the key is cycled. In many cases the ECU will just shut off the engine due to lack of fuel.

You should check the connector for the fuel heater on the fuel filter head assembly. The stock units tend to melt around the terminals that are built into the fuel assy. We would recommend filling the connector cavity with silicon sealant or purchasing a new filter head and wiring kit for the fuel heater (TSB 18-011-09, new part number 68043089AA is for fuel water separator assy). If you suspect a vacuum leak in the fuel system this would be the first place to address the issue.

The diagnostic limits might be a tad to tight for the fuel system, we are opening them up with the GDE tune to minimize the potential for this issue and setting a CEL if the issue occurs, no more engine shut-off without a CEL for fuel system. We would agree that the engine reaction to less than adequate fuel is no aggressive and the vehicle should never shut off on its own.
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davidmay

Joined: 25/08/2009 05:53:00
Messages: 5
Location: Houston, TX
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I have to say that your explanation as to what might be going on is the best I have received, and it makes a lot more sense than simply I have an air leak into the fuel system.

I will be replacing the filter head and filter just as soon as I can, since I believe the head is still the old design (which tells me the previous owner didn't follow at least this part of the preventive maintenance schedule, as it was suppose to be replaced at 25,000 miles according to the owners manual).

Once I get the Jeep set up for towing in a couple of weeks, you can expect my Eco Performance Tune order . Thanks for the help.
bardwell02

Joined: 05/03/2010 21:14:07
Messages: 2
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Hey guys I'm going to borrow this thread as I'm kind of in the same boat. Original owner of an early 2005 CRD. Up until last month was convinced it had to go at 70k miles (65k now) since I haven't found a dealer here in Dallas I trust. But the $50k for the Touareg TDI to go with my wife's new Jetta TDI was too much, the CRD's been paid off for a year so... thinking I'll keep it for now.

I've been towing a 5000 lb. boat with this since new; mostly I leave OD off and set cruise at 60. This is only 5-6 times a year (god how much is that boat payment?). Never tried any kind of grades I'm a flatlander. As far as 'shudder' well one time with my old man's little center console in OD, maybe. But no other trans issues. Overall I've been pretty lucky I think. As a long time LOST watcher, recently did the airbox mod and unplugged my MAF sensor (ORM). I miss laying down smoke screens but wow it runs great. Provent, lift pump, and exhaust are all on the list now, and of course the GDE tune. Which sort of leads me to my question.

I have the replacement F37 TC, and no they did not replace the pump. Getting ready to have the trans serviced for the first time (62.5k). My concern is that, since I've had no issues, if I have the GDE tune, and I going to kill it? I've seen where people have used trans shudder (don't have it) or rear main seal leak (don't have it) to get a warranty replacement of the TC, but If I go in with my perfectly functional trans, oh well. So assuming I can't arrange a warranty replacement, should I try the ECO tune? It's got plenty of power for my daily crawl, it's just the towing where I'd like as much torque as possible. If I did the ECO tune and it started shuddering, is it fairly transparent re: the dealer won't know it's been modified? Last resort, I do have a trustworthy trans shop lined up here, curious whether, if I'm paying the bill, a Suncoast TC is a better bet than the Euro TC?

Thanks everyone for their help and advice; I really like this truck, 3 years ago we all thought we'd be driving diesel 1/2 ton pickups by now but you see how that worked out, right? (BTW, if you do serious towing with one of these, Curt Mfg D-26 ball mount is perfect - 12.5 inches long, just clears the spare in the flipped positon, which is 3/4" up and pretty level with my 500+ lb. tongue weight.)


2005 Limited CRD (build date 2/25/05)
GreenDieselEngineering
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Joined: 10/07/2009 07:25:47
Messages: 353
Location: Southeast Michigan
Bardwell02,

You must have a KJ that was built on a Tuesday or Wednesday, it sounds very solid. The ECO tune is the best path for your situation as it has a torque limitation while the TC is in lock-up to minimize the potential for shudder and lengthen the life of the TC. When unlocked, the trans will have a substantial torque increase over stock throughout the rpm range at full go pedal. The tune is transparent to a dealer scanner, we do not change the part number. The dealer may check for supercedence for the ECU part number, so we highly recommend you have the dealer complete all TSB engine controller flash updates prior to purchasing a tune. Plus the TSB firmware updates add additional software features that benefit the application (with the proper aftermarket tune of course!!).

As for the TC, we have not personally tested the Suncoast, we tend to look for the least expensive option to solve any problem. The "shudder issue" is solved with the Euro spec mopar TC and it should be less than $300...lately Chrysler seems to be adding mark-up to the TC as the price started around $200 last September. It is still a good deal. The shudder is caused when the springs in the lock-up clutch bottom out and cause the secondary reaction of clutch slip-stick, which translates into the high frequency vibration in the vehicle. The new euro converter increases the capacity about 100 ft*lb and this is enough to prevent the springs from going solid.

We have several customers with the Suncoast converter, mainly running the HOT tune. You might get some good feedback from them if you start a new topic about it.

Do you want the TC to grenade before the waranty or at least be able to demonstrate shudder with the trans?
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bardwell02

Joined: 05/03/2010 21:14:07
Messages: 2
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Thanks for the response. I had definitely considered the idea of forcing the issue, if the trans acts up while still under warranty. Gotta find a dealer here though which hasn't gone well. Don't want to destroy it though like I said above this is the orignal pump. So would Hot tune be the ticket then? Instant shudder? And that shudder will easily lead a tech to replace TC/pump? Hypothetically.

I would like the extra torque under lockup that the Hot tune has, I think on the flat this could pull my 5000#, locked in 5th. Afraid to try that now.

2005 Limited CRD (build date 2/25/05)
GreenDieselEngineering
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Joined: 10/07/2009 07:25:47
Messages: 353
Location: Southeast Michigan
If you want to demonstrate "shudder" the HOT tune will definitely take care of this and the shudder is easy to stop if you have it by letting off the throttle. The added torque of the HOT tune will be a significant benefit to being able to hold gear longer while pulling a trailer.
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