Mercedes-Benz was once a legendary name in diesel power. Hop into a cab in another country and you might find a Mercedes diesel workhorse with a million or more miles under its wheels. How do you make that even better? Drop a Benz diesel into one of the SUVs of the iconic Jeep brand. Back in the mid-2000s, Jeep did just that as it built what sounded like a dream scenario. The Jeep Grand Cherokee CRD combined the off-road capability of a Jeep SUV with the supposed reliability of Mercedes diesel power. Yet, the resulting ride was too dirty to be sold in five states. Perhaps worse is the documented instances suggesting this diesel isn’t as reliable as the ones of decades past.
If you spend enough time in the fandom of diesel you’re almost certain to hear someone talk about the mythical million-mile diesel. The premise is that in the not-too-distant past, Mercedes-Benz built diesel passenger car engines so bulletproof that there are taxis and private cars out there still chugging around after a million miles under their wheels. Then you plug “million-mile Mercedes” into a web search and find out that at least in some cases, the stories are true.
Just last year, Teneriffa News reported that there’s a W123 Mercedes-Benz 240D that’s been running around the Grand Canary Island since 1988. Over that time, the Benz has been driving around 435 miles every single day as a taxi. The publication says if you add up all of the cab’s driving it comes out to an astonishing 4.35 million miles and it’s noted that the darn thing is still out there carrying passengers today.
Perhaps even more shocking is when you find out that the cab is only on its second engine, which means that no matter how you slice it, this car went well over a million miles before needing a new engine. Of course, the rest of the car needed refurbishment along the way. The W123 isn’t known for having the best driver seat, so I’m not surprised to hear that’s been swapped out for another throne. Still, the mileage is incredible. The Mercedes-Benz Museum in Stuttgart has a 2.8-million-mile W123, but that one has been through at least two engine replacements since new.
It’s not just the W123 either, as Mercedes E-Class W124s have surpassed the million mark and at least one late 1990s E-Class W210 has come close. Who knows how many million-mile taxis are buzzing around Europe that haven’t gotten Internet attention? The legend of the million-mile Mercedes diesel is so prevalent that people will sell their old, beat-up Benzes advertising their cars’ “million-mile” engines even if their actual car has nowhere near that mileage.
In the mid-2000s, Jeep of all brands proposed an interesting idea. What if you could get Mercedes diesel power, fuel economy, and reliability, but in the macho package of a Grand Cherokee? Jeep discontinued its Italian VM Motori Liberty CRD and in its place was the Mercedes-powered Grand Cherokee CRD, an off-roader with so much promise.
Softening Up
Jeep went through quite the evolution in the 2000s. The legendarily capable XJ Cherokee was killed off and replaced with the softer Liberty, much to the pain of Jeep fans like David Tracy. Jeep, then under the rule of DaimlerChrysler, didn’t just leave its smaller off-roader alone. Later, it was time for the Grand Cherokee to become something new.
In 1999, the Jeep Grand Cherokee WJ replaced the ZJ. This SUV was mostly new and shared only a handful of parts with its boxy predecessor. It also had a lot to live up to. The ZJ was a Larry Shinoda and Joseph Papai, Jr. design masterpiece that brought just the perfect mix of luxury, power, and off-road prowess to the early 1990s, from my retrospective:
As for the Cherokee itself, there are a number of reasons behind its popularity. The unibody SUV was stiff competition for the Ford Explorer and came with standard features like a driver airbag and an Electronic Vehicle Information Center computer that monitored the SUV’s systems. That EVIC system had a screen that gave the driver information like the date and time or the service interval of their vehicle. Of course, if you’ve driven one of these you’ve probably noticed the trip computer giving you information like your compass heading, outside temperature, or fuel range remaining. Other available features included keyless entry and a glowing ring around the ignition cylinder for nighttime ease.
Many of those features weren’t exclusive to the Grand Cherokee. As a kid, I remember watching the green glow of that trip computer but in a Dodge Caravan. As an adult, I bought a second-generation Dodge Grand Caravan that had that same system.
In terms of power, the Grand Cherokee offered as small as the 4.0-liter AMC straight-six making 190 HP and 225 lb-ft torque. And for most of the ZJ’s run, the biggest engine was a 5.2-liter Magnum V8 making 225 HP and 300 lb-ft torque.
That power and comfort were backed up by a pair of solid axles, a selection of 4×4 systems, manually-shifted low range, and a five-link coil suspension in front and rear. The ZJ is such a capable off-roader that you still see them climbing all over off-road parks and bombing down fire roads all over America. David Tracy noted at the old site that the boxy ZJ and its bubbly WJ successor share the same five-link front suspension, but things get different in the rear where the WJ got a three-link setup that retained the lower control arms. What was different was the two upper links were replaced with a single control arm with a ball joint.
It’s noted that the ZJ and WJ share just 127 parts. As C|Net writes, Porsche also had a hand in beefing up the WJ’s unibody for greater strength. David then notes that the WJ is more than some suspension changes and a new body:
Other changes from ZJ to WJ included the re-mounting of the spare tire from inside the vehicle cargo area to under the cargo area false floor. This pushed the floor down, and sent the fuel tank sagging. That’s why, when you drive behind a WJ, you see that big, bulbous fuel tank. It’s hideous and actually led to a recall due to concerns about rear impacts.
The heavier and larger WJ also ditched the ZJ’s 5.2-liter and 5.9-liter V8s for a new 4.7-liter V8 motor. That eight-cylinder came with a five-speed auto, though the 4.0-liter inline-six also offered—and all automatic variants of the ZJ predecessor—came with four-speeds.
There are a number of other difference between the WJ and the ZJ that preceded it, including more sophisticated transfer cases and differentials, but the main point is that the WJ Grand Cherokee is the round, bubble-like Grand Cherokee with the gas tank that sags and the 4.7-liter V8 that nobody really loves, even if it’s bolted to what many consider a pretty tough five-speed automatic.
I am surprised to find a lack of any real details about the WJ on Jeep’s site. Jeep’s history site mentions the WJ in passing, saying it was marketed “as the most capable SUV ever.” I haven’t been able to find exact production numbers, but it’s believed that well over a million examples were sold over the WJ’s 5-year production run.
What Makes A Jeep A Jeep
According to a piece at Rockcrawler.com from 2004, DaimlerChrysler decided that the Jeep Grand Cherokee needed a complete redo. Company brass noticed that the WJ Grand Cherokee had a different slotted grille than the Wrangler and the Liberty. Likewise, the suits felt Jeep’s design philosophy wasn’t really cohesive, and they wanted every Jeep to be immediately identifiable through more than just badges and grilles.
Meanwhile, as Gardner Business Media reported in 2004, the engineering team had their own challenge. Reportedly, Jeff Bell became part of the Jeep team in 2002, where he was anointed as vice president of the group. Jeep’s engineers had a guide of ‘Every Jeep will go down the Rubicon Trail’ and the challenge was turning that simple statement into capable vehicles. The problem was that a statement is hardly a roadmap, so Jeep’s team set out to set parameters to define what a Jeep is.
As Gardner Business Media writes, Jeep’s team eventually landed on approximately 37 criteria for defining a “Jeep.” For example, a real Jeep must be able to ford 8 inches of water for at least 50 feet at a speed of at least 45 mph. In other words, the criteria didn’t say how the engineers had to design the Grand Cherokee, but the targets they had to hit.
Once the Jeep team figured out all 37 criteria, the targets were then grouped into five categories: articulation, ground clearance, maneuverability, traction, and water fording. If the vehicle in development hit all targets, then it got its Trail Rated badge. It’s notable that the team knew that not every Jeep would be Trail Rated. For example, 4×4 was a requirement, so any Jeep that’s just two-wheel-drive wouldn’t be deserving of the badge.
Let’s go back a couple of paragraphs for a moment here. Remember how I said the criteria didn’t say how the engineers hit a goal? To explain that further, it also meant that the engineers were tied to a specific technology to hit their goals.
David Tracy will be one of the first to tell you that the WK Grand Cherokee was a step towards a softer SUV as it ditched a solid front axle for an independent front suspension. However, as Gardner Business Media writes, this was done because Jeep’s engineers determined the independent suspension to be better overall, from Gardner Business Media:
One of the issues of what a Jeep is—or isn’t—tends to be considered by some people to be a factor of physical aspects of the vehicle: the what, not the how. What is perhaps the most controversial aspect of the ’05 Grand Cherokee from that point of view is the deployment of an independent front suspension. (At this point we’ll pause to let some of the true Jeep zealots pick themselves up off of the floor.) This is a short- and long-arm (SLA) suspension that features nodular iron, single-piece lower control arms; forged steel upper control arms; aluminum steering knuckles. While it is often thought that solid axles are better for off-roading, it was determined that this independent arrangement—which, incidentally, provides about 10% more travel than the system it replaces—not only reduces unsprung weight by 100 lb., but also reduces head-toss during off-road driving. In other words, the Jeep engineers found a better solution, yet one that still fulfills the requirements for a bona fide Jeep. Tom Cowing, manager, Jeep Grand Cherokee Vehicle Development, describes it as a “Jeep-engineered independent front suspension.” Bell observes: “That’s what Jeep engineers do. They take an idea and make it better.”
The Gardner Business Media piece mentions that Jeep had so much brand equity in 2004 that it could slap a Jeep badge on a less-capable vehicle and probably still make money. Bell pushed back, reportedly saying that would never happen. If Jeep were to make a less-capable vehicle, it would start as a 4×4 Trail Rated Jeep before having content taken out.
Gardner concluded that it was unlikely Jeep would make a lesser vehicle by starting with a car platform. The car platform-based Compass entered production two years later.
Going back to the WK Grand Cherokee, the big news with the SUV was what happened with the front suspension. However, when the SUV launched in 2004 for the 2005 model year, Jeep boasted about how the body wasn’t just new, blocky, and modern, but how it was also practical. Jeep noted that the WJ wore expensive and heavy cladding to protect the body from debris kicked up from the SUV’s tires. The WK’s designers did away with the cladding, instead designing a body with bulky flares. This made the SUV look muscular and also enabled it to protect itself without need for cladding.
The WK Grand Cherokee also boasted the option of Quadra-Drive II four-wheel-drive, which consisted of a locking New Venture Gear NV245 transfer case driving front and rear axles with electronic limited slip differentials. If that was too fancy for you, there was also Quadra-Trac I, which was permanent all-wheel-drive with a 48/52 percent power split and Quadra-Trac II, a 4×4 system featuring the NV245 transfer case and off-road traction control.
All of that off-road capability was wrapped up in a package with a greater focus on luxury. Jeep’s releases note that the WK had dashes of chrome and jewel-style lighting to give the SUV a classy, upscale look. The features also backed this up as a WK could be had with HID lighting and a DVD player for rear seat passengers. More chrome was tossed into the interior and Jeep talked up how the two-tone dash and upgraded interior materials were supposed to bring on even more luxury.
Of course, as Motor Trend wrote in 2004, a lot of this happened because the suits at DaimlerChrysler noticed that Jeep owners weren’t just rugged off-roaders anymore, but families were also picking up Grand Cherokees to conquer mall parking lots rather than the rocks of Moab. So, the WK Grand Cherokee is more family-friendly from that DVD player to the rack and pinion steering.
Mercedes Diesel Power
In 2004, DaimlerChrysler made a decision that still seems a bit shocking today and announced diesel engines targeted at those who wanted to save money and go green, from my retrospective on the Liberty CRD:
In 2004, DaimlerChrysler announced it had new vehicles in its pipeline for people who wanted to go green and save money at the pump.
Reportedly, DaimlerChrysler knew that America was still a bit sore about its past with diesel passenger cars. Diesels gained a reputation for being smoky, loud, slow, and in the case of diesels from the ’70s, unreliable. But diesels had come a long way from then and DaimlerChrysler wanted to prove that diesel was cool. Its plan to make that case was the launch of the Mercedes-Benz E320 CDI and the Jeep Liberty CRD. One would show that diesels are great in luxury cars while the other would prove diesel’s worth off-road. Both were touted as ways to save money in the long run.
The Liberty CRD was an early success as 11,000 buyers flocked to the model, but it wasn’t a model that was meant to be. The Liberty CRD was sold from 2005 through 2006. It wasn’t killed off because of poor sales, but because the VM Motori four-cylinder turbodiesel under the hood wasn’t clean enough for 2007’s emissions regulations.
But DaimlerChrysler wasn’t done with its diesel experiment just yet. The Liberty CRD left the ring, tagging the larger Grand Cherokee CRD in to finish the fight.
The Jeep Grand Cherokee CRD hit the market in 2007 and its mission was similar to the Liberty CRD. Chrysler said the Grand Cherokee CRD was its first diesel-powered SUV for the American market and like the Liberty, it was marketed toward the driver who wanted to save money at the pump while also being a little greener. From Jeep:
The new 3.0-liter V-6 CRD engine, built by Mercedes-Benz, produces 215 hp (160 kW) @ 3,800 rpm and 376 lb.-ft. torque (510 N•m) @ 1,600-2,800 rpm and gets an estimated fuel economy of 20 miles city and 25 miles highway for 4×2 models and 20 miles city and 24 miles highway for 4×4 models. Most recently, the engine earned a spot on “Ward’s 10 Best Engines” list.
The 2007 Jeep Grand Cherokee CRD offers class-leading torque, outstanding towing capacity (7,400 pounds), and class-leading driving range of approximately 450 miles. Clean diesel technology also improves fuel economy by up to 30 percent and has up to 20 percent fewer carbon dioxide (CO2) emissions.
At the time, the most thrifty engine for the Grand Cherokee was a 3.7-liter V6 making 210 HP and 235 lb-ft of torque. It was rated for 17 mpg in the city and 21 mpg on the highway. So, opting for the diesel, which was the 3.0-liter Mercedes-Benz OM642, meant substantially more torque and a bit better fuel economy. For those of you counting, the diesel punched out more torque than the 369 lb-ft of twist offered by the 5.7-liter Hemi V8 of the day.
You got all of that for the price of $38,475 ($59,836 today). That price also got you the nice Limited 4×2 trim level. For comparison, a regular Grand Cherokee Limited 4×2 was $35,180 ($54,711 today).
How did this work out in real life? Well, Motor Trend liked it:
The 3.0L turbodiesel is a relatively new development. It features an electronically controlled, common-rail, high-pressure injection system with double overhead cams, four valves per cylinder, and a 4,500-rpm redline. This slightly undersquare engine is on the top tier of diesel tech. It’s had a couple of years in the European markets for debugging, fitted to the same Jeep platform there, as well as to the Euro version of the Chrysler 300C. The engine is fully compatible with the new ULSD (Ultra Low Sulphur Diesel) regulations and has an exhaust particulate filter (get used to them) and holds an impressive 10 quarts of lube oil.
We had a chance to drive both a Hemi-powered WK and the CRD, and the differences in acceleration ain’t like the proverbial tortoise and hare. The butt-dyno says the diesel we tested had the edge from zero to 30 mph. With 376 lb-ft on tap from 1,600 to 2,800 rpm, it ought to, but whatever the Hemi gains further up the rpm range, the diesel isn’t as far behind as you would expect. It does tend to get a bit winded at higher rpm, but like many Euro-diesels, it does a pretty good gasser imitation. That includes the noise and vibration department. Yeah, it’s a tad more rough than the gassers, but this is a diesel almost anyone could easily live with. Handling and braking of the 3.0 CRD on the street is on par with the other WK models.
Off the highway, our test rig easily handled the DaimlerChrysler test track. It ‘wheeled like the other WKs we’ve driven, but with a lot more low-end grunt to play with. The course uncovered what we hope, and were told, is just a glitch. In low-range, the throttle is excessively sensitive. Talk about the herky-jerkies! Also, when trying to left-foot brake, the throttle-by-wire freaked out and kept pulling back on the power. Only one rig was available for trail tests, and it was a preproduction test beater with some serious test miles behind it. The engineer riding along told us the programming for the system was being refined to be more trail-friendly. We hope so.
Car and Driver‘s review notes that the CRD pulls hard until 90 mph, then acceleration falls off of a cliff. So, this isn’t exactly an Autobahn bomber.
Still, a diesel sounds like the perfect engine for a big off-road SUV. As Jeep noted above, that torque hits hard almost just off idle, which is great for both towing and off-roading. And while those fuel economy gains aren’t huge, diesels are great at giving you long legs while on a road trip, both when empty and when towing.
So why am I stopping short of calling this a Holy Grail? The CRD even sold for just a couple of years between 2007 and 2009. Nobody knows how many were produced, but they’re believed to be rare.
The Headache
The answer comes from our very own Thomas Hundal, who writes excellent breakdowns of vehicles and engines you may call “Achilles Heels.”
So what is the OM642, and which vehicles came with it? Well, back in the mid-aughts, Mercedes-Benz wanted to replace its aging inline-six and inline-five diesel engines with one turbocharged diesel V6. The result was an undersquare (long stroke) all-aluminum 72-degree unit with a variable geometry turbocharger. You’ll find this engine in 2007 and newer E320 CDI and E350 BlueTec sedans, 2007 and newer R320 CDI, R350 BluTec, ML320 CDI, ML350 BluTec, and 2008 and newer GL320 CDI and GL350 BlueTec SUVs, 2012 to 2013 S350 BlueTec sedans, 2007 to 2008 Jeep Grand Cherokee diesels, the rare GLE350d and GLS350d SUVs, and a buttload of Sprinter vans.
If you’re a fan of old Mercedes diesels, you might think the OM642 has to be one of those “million-mile” engines right? Sadly, the piece Thomas wrote shows plenty of evidence that these engines can have all sorts of issues. His article notes dead turbo actuators, intake swirl flap failures, oil leaks galore, NOx sensor failures, and at their worst, main bearing failures. Those are just the issues Thomas talked about.
If you scroll through forums, you’ll find a variety of other failures like glow plugs, fuel pumps, blown turbos, and starting issues. Of course, anecdotes on forums are not data. You can also find a lot of these SUVs with hundreds of thousands of miles on them, too. However, it appears that when these engines break, they cost a lot of money to get back on the road again. Thomas continues with the pickle you’d end up in after a main bearing failure:
Looking around on car-part.com, an online salvage yard marketplace used by many independent shops for second-hand parts, a good used replacement engine goes for anywhere from $6,500 to $8,500, not including installation. Considering many OM642-engined Mercedes-Benz products have depreciated to that level, catastrophic engine damage would make many OM642 diesels uneconomical to repair.
Then there’s the problem of Jeep’s claim about this engine being a cleaner unit. At launch, the Jeep Grand Cherokee CRD was legal to be sold new in only 45 states. Why? The engine didn’t meet the strict emissions standards for California and the states that follow California’s lead, which included Maine, New York, Vermont, and Connecticut.
If you’re not deterred, I have good news for you: These SUVs are still pretty obscure and don’t appear to have that strong of a collector market. It’s not hard to find a Jeep Grand Cherokee CRD for under $10,000. Finding a mechanic who won’t shudder at the sound of “diesel Jeep” will be a different story. Have you owned one of these? If so, I’d love to hear about your experiences in the comments.
All of this adds up to a vehicle that could have been a true Holy Grail, but falls short. Imagine a diesel Jeep product that not only hauls like a freight train but could also last until the heat death of the universe. That’s what the Grand Cherokee CRD could have been. As diesel continues its path to irrelevancy in passenger vehicles, SUVs like the Jeep Grand Cherokee will go down in history as a weird example of when automakers tried to keep money in your wallet and be greener through Rudolf Diesel’s old invention.
(Images: Manufacturers)
248K on the 4.7L in my 2004 “Khaki Silver” Durango and I have to say it’s one of the best engines I’ve owned out of 146 cars over almost 30 years.
I have extensive experience with this Jeep. My grandpa bought one new in 2008. He pulled it behind is motorhome in the winters and off road around his large property in a Michigan to pull trailers and traverse the grounds.
The Jeep was great as a pulling vehicle and one could argue pull more than what it was rated to do so.
It was not super reliable. It always had some “odd” issue pertaining to the engine. Many different Mopar and Mercedes mechanics worked on it over its lifetime.
My grandpa loved the Jeep and kept it around until he died in 2022. At that time it had north of 150k on it and had an intermittent issue of not wanting to start that no one could diagnosis.
I like it, but never enough to recommend it to anyone.
I owned a 2007 Limited with the Quadra-Drive II 4×4. Bought it CPO with about 25,000 miles, traded it in with around 140,000 miles. Overall it was very reliable – the only odd thing was a tendency to have glow plug failures. At the end the intake manifold had carbon build up which would have been a relatively expensive repair, but not a difficult one – just lots of labor. The OM642 might have been rare in a Jeep but there are lots of them running around in Mercedes ML’s and in Sprinter vans. Overall ours was a decent car – plenty of performance and decent fuel economy. For a Chrysler-built product it was pretty reliable as well.
Wish I had the time and money to buy the OM617 kit they make for XJs and make the diesel jeep AMC or chrysler should have.
Being heavily into Mercedes diesels (also made my own fuel for them), and knowing my daughter would be heading off to college in 2010, I followed the Liberty diesels with interest thinking we could pick up a 4 or 5yo one to serve her out of state.
It soon became obvious that it wasn’t what I wanted for a vehicle that would spend 5ish years 3hours from me. Wish I could recall the details from the old Mercedes Shopforum, but time has erased those and all I remember was the gas engines’ hunger for bearings.
Surprisingly, an 05 Stratus lasted her some 8 or 9 years instead
Would be nice if we could get the diesel Land Cruisers here (or their Lexus counterparts).
My Dad owned one of these from new for 5-6 years (I worked for Chrysler at the time so he used the family discount). He bought it for the 80-90 mile round trip drive to work. Life was decent with the Jeep until it wasn’t. The biggest issue I recall happening (twice) was the fuel tank rusting from the inside out and fouling the fuel pump. Like another said, the dealer was stymied, couldn’t get parts and wanted nothing to do with it.
When he finally traded it in on a new Durango Citadel, the trade in value was surprisingly good at a South Florida dealership. Apparently the 4 x 2 models are highly prized in South America to tow horse trailers and for other heavy towing duties on large farms.
This Jeep was a good idea but flawed…
Interesting article.
“Let’s go back a couple of paragraphs for a moment here. Remember how I said the criteria didn’t say how the engineers hit a goal? To explain that further, it also meant that the engineers were tied to a specific technology to hit their goals.”
Shouldn’t that read that the engineers were NOT tied to a specific technology to hit their goals?
Using up the OM642 in a W164 M-class. No issues, currently at 150k miles. I do like the torque and economy for towing. Is there another engine from 15 years ago that offers 18mpg towing your latest addition to the fleet home on a rented Uhaul trailer?
Uhh yeah actually, there are a number of 3/4 ton diesels, 15-30 years old, that can deliver economy in that range depending on a whole lot of variables.
From ’07 through ’09 I had an ’07 dodge ram 3500 2wd dually with a 5.9 cummins and 6 speed manual. I got 15-18mpg around town, and well over 20 on the highway all while towing a 20 foot box trailer full of cabinets and tools, over stevens pass weekly. I put ove 1000 miles on it weekly for two years. Right tool for the job and excellent fuel economy. Just sayin’.
Wait so is this a Mercedes (car) article or a Mercedes (person) article or an entirely DT article? I can’t wrap my brain around all these characters.
I didn’t own one of these, but a good friend’s mom bought a discount 2008 Limited diesel model in early 2009. The thing was in for warranty work so much the dealership offered to buy it back and give her a discount on a 2009 Overland with the 5.7L Hemi. I never got to ride in the diesel, but my friend’s mom often said the only thing the diesel did better than the Hemi was fuel mileage, but that was mostly due to having only filled the fuel tank with diesel twice before she sold it back to the dealer. The Hemi lasted ten years and 220,000 miles before succumbing to upper Midwest rust, at which point it was replaced by a WK2 Overland with the Hemi.
I always thought Mercedes’ diesel engine of her dreams was the V10 TDI, not some silly OM642. Or was it a Ford 7.3 Powerstroke?
Don’t recall it being in a Jeep though. Maybe her and DT cooked something up?
I took one of these in Overland guise home for a couple day test drive in ’06. Really liked the Jeep, but couldn’t justify the expense coming up from a paid-off 2002 WJ. From the issues I’ve heard, probably good I didn’t get it. Though I’ve now had a 2018 WK2 Trailhawk and currently drive a 2021 JL Rubicon and 2022 Ram 1500 with the 3.0 VM diesel. Something about driving with the doors off and hearing the diesel gets me hot enough to start a personal regen.
My admiration and respect for Mercedes-Benz passenger car Diesel engines begins and ends with the OM616 and OM617. I’ve owned examples of both. No other M-B Diesel engines will ever be this good.
Do you like the naturally aspirated or turbocharged version better?
Both have their place. I’ll pick the naturally-aspirated version for durability, the turbo for power.