It’s Here! Jeep Wrangler with Diesel News

[Dan Grec]

You need to evaluate the the micron needs of the engines systems, usually factory filters are 3-5 micron absolute, but it varies a bit. You also need to consider nuisance plugging. In some cases a two filter system, the first being a 40 micron screen type (possibly with centrifugal water separator), and second being a final filter.

Note that most of these engines use in-tank lift pumps that make 50psi+. So many big rig designed systems can't handle the pressure. This also means there is a pickup screen in the fuel tank, which can plug with debris.

Common rail systems have higher flow rate needs, as the fuel lubricates and cools the HP pump and injectors.

Thanks, I was planning on exactly that 2-filter setup - one around the 40 micron range with a water seperator, and then another much finer one. I'll carry multiple spare filters.
This is what many Overlanders do in Africa, it seems to work pretty well.

And yes, I'll have to figure out the flow requirements of the engine and the pressure of the fuel system and then get/design a filtration setup that is appropriate.
I'm hoping Gale Banks can send me down a good starting path from their experience with this engine and running military diesel through it.

-Dan

 

[Charles R]

i might be interested if they put it in a JK body. Surely they have a few around.

New diesel. DPF. DEF. No thanks.

I've been contemplating building a 2013 JK with the 2008 Grand Cherokee CRD engine. Both use the NAG1 transmission, so I'd only have to focus on the engine details.

 

[dreadlocks]

Both use the NAG1 transmission, so I'd only have to focus on the engine details.

I doubt they are both geared the same tho, so you'd want the gearbox out of the diesel also.

 

[luthj]

I am 98% sure the NAG1 used in both has the same gear ratios. The axle gears would surely be different though.

Getting a standalone ECU/ECM for the diesel is going to be difficult and expensive.

 

[ram2500_24v]

I have a Jeep TJ with a VW diesel (1.9l ALH code). I have a very mild tune on it so it is not a powerhouse but gets the job done with 35 mpg mileage. After working on Jeep Grand Cherokee's Diesel's I wanted something very simple and this thing is so easy to repair. And If I don't like something, I have the freedom to change it without worrying about warranty and all that other garbage.

 

[Dan Grec]

I've been contemplating building a 2013 JK with the 2008 Grand Cherokee CRD engine. Both use the NAG1 transmission, so I'd only have to focus on the engine details.

I think that was the Merc OM648 V6 diesel, correct?

As of right now, the only standalone ECU for that engine is made by Bosch, and is around $7k.
There is a guy that made a standalone for the OM606 series engines, and he said he's working on one for the OM648 and variants. When it's working, it will unlock a lot of Merc diesel engine options.

Here is the thread where the creator of the ECU mentions he's making one for the common rail diesels:

Common rail diesel discussion thread

-Dan

 

[Charles R]

OM642. And the trans uses the same ratios. And rear end gears are the same too. It's actually funny that my hemi Grand cruises at a lower rpm than my crd. They both have the same 3.73 rear end ratios, but the hemi's 545rfe trans uses a lower top gear ratio.

 

[pittsburgh]

I have a Jeep TJ with a VW diesel (1.9l ALH code). I have a very mild tune on it so it is not a powerhouse but gets the job done with 35 mpg mileage. After working on Jeep Grand Cherokee's Diesel's I wanted something very simple and this thing is so easy to repair. And If I don't like something, I have the freedom to change it without worrying about warranty and all that other garbage.

What year is your TJ? I have an 05 Unlimited I would love to put a diesel in. Seems ridiculous that my YJ and CJ-7 both got 20'ish MPGs and my TJ gets 14 MPG on a good day lol.

 

[ram2500_24v]

Mine is a 1999 so it has the AX-15 transmission and unfortunately the Dana 35 axle. I wish I could afford an unlimited as that extra 15" would great to have on trips.

 

[dreadlocks]

you can get an ALH up to about 300ft tq w/a turbo upgrade and injectors, and they still ultra reliable..

man I'm jealous.. at this point I'm convinced it'll be easier/better to just fix up the TJ, sell it.. import a canadian a VW Iltis... the ALH will bolt right on in w/out any trouble at all.. and I wont have all these annoying plastic bits that keep breaking.

 

[ram2500_24v]

Yes you can really upgrade these little engines and they seem to take the abuse for awhile anyway. I guess my original plan from the start was to NOT spend a ton of money on upgrades because in my mind it defeats the purpose of putting a fuel efficient engine in. If you spend $2000 plus on upgrades I might as well have taken that money and just bought gas for the 4.0l engine and went on a few trips and enjoyed it. So far I only have the stage 1 Malone tune which was basically required when a lot of the electronics were deleted from the ECU. It seems to work well with the 3.73 gears and 31in tires.

 

[SSF556]

Thanks for the info. You obviously know way more about it than I do.
That's good to hear that high sulfur might actually be a good thing in terms of lubrication.

And yes, I would run a two-stage water separation / filtration setup, whatever the finest filter I can run would be (1 micron?)

-Dan

I think that was the Merc OM648 V6 diesel, correct?

As of right now, the only standalone ECU for that engine is made by Bosch, and is around $7k.
There is a guy that made a standalone for the OM606 series engines, and he said he's working on one for the OM648 and variants. When it's working, it will unlock a lot of Merc diesel engine options.

Here is the thread where the creator of the ECU mentions he's making one for the common rail diesels:

Common rail diesel discussion thread

-Dan

Dan I have 17 years of diesel experience with one of the largest diesel manufacturers in the world.

I currently own a 2008 Grand Cherokee with the OM642 and I am a big fan of GDE. I have over 40,000 miles with their tune and I have gotten better MPG and no mechanical issues! I also just bought a 2012 Ram Cummins. 2012 was the last year with no DEF. I have 2 diesels cars and 1 diesel tractor and not one of them has DEF. I hope you see the trend!

Since we introduced DEF to the diesel equation back in 2010, DEF related issues, sensors, ATD issues etc quickly became our #1 warranty issue and my customers have backed that trend up. Also keep in mind that modern diesels have very low tolerances when it comes to fuel quality. When we see injector issues at a customer the first thing we do is find out who is providing the fuel, biodiesel content, water , DEF quality etc. As you know the quality of diesel fuel in 3rd world countries is questionable at best. If we are questioning fuel suppliers here you will run into issues with a DEF equipped diesel engine.

Can you run DEF engines in a 3rd world?...for sure but you are playing the odds. Frame mounted filters will help but they are not the bullet proof. We put Davco frame mounted filters standard and still see fuel pump and injector failures. Also remember that DEF is generally not filtered and if not a good quality or not the correct water % it will hurt the system.

That being said I would look for a pre DEF diesel powered vehicle. Also you have clearly proven in your travels that gas power is more than adequate from a range standpoint and a modern gas engine can eat 3rd world gasoline without any issues.

Scott

 

[SSF556]

I've been contemplating building a 2013 JK with the 2008 Grand Cherokee CRD engine. Both use the NAG1 transmission, so I'd only have to focus on the engine details.

I have a 2008 Grand Cherokee with OM642 and this build has crossed my mind several times. I would honestly pull the entire electrical system out of the WK and put in the JK. The issues with the WK is gearing as someone else mentioned. It is geared too high for a diesel, great low end power but RPMs at road speed 70mph + and the WK runs at over 2500 RPMs. Jeep should have geared that vehicle to run at 1700 or 1800 rooms at 70, 71, 72 mph....

 

[Charles R]

Yeah, my thought was that if the stock ECM from the CRD wasn't able to wire up/communicate with the JK properly, I'd plan to do it the way you're thinking. But it would have to be a 2008, as the '07 has a lower CANBUS bit rate. I'm dreaming that the protocol was standard across the platforms AND that it stayed common until the JK got the Pentastar. The earlier JK's didn't have the NAG1. Knowing auto manufacturers as I do, it's a pipe dream though!

My other dream is to put my drivetrain into an old Jeep FC that's for sale near me...


Edit: btw, did you know that the 3.7 V6's have 3.07:1 axle ratios? Since your grand is QT2, that would be a direct bolt in.

 

[TexasTJ]

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