The engine started missing and eventually sounded like it was running on 3 cylinders. The dealer says they can't find the problem...

 

Diesel or gas?

 

Diesel, so a 4 cylinder.

The technicians hooked up a diagnostics machine, but couldn't trace the source of the problem.

 

diesel runs off compression... so maybe your pump/injectors are failing?

 

it has now done 55,000 Km (roughly 35,000 miles) and I have always filled it up with the highest grade low-sulphur diesel. Nothing is impossible though. This is my first diesel - can the injectors get fouled or blocked at such a relatively low mileage?

 

I would change the fuel filter. Maybe water in the Diesel.

 

Also, after cleaning/changing the fuel filters- usually there 2, a "primary" and "secondary", check for a blocked or dirty air filter. You would be amazed what gets in there. Then check the fuel lines, if they are diesel-damp, they will suck air before fuel, cracked fittings- all mechanical issues that a thorough visual will find. Don't hesitate to really clean things off, use a magnifying glass to check out hose connections, flares, abrasions. Air leaks are pesky critters...Good Luck! Wish we had a Diesel JK to examine stem to stern..

 

x2

could be water in the diesel... depending on where you fill up. not unheard of.. but why would it consistently be causing 3/4 not to fire, IDK.

we only have one 'low-sulphur' fuel grade available for public consumption here in the US so maybe standards where you live are different.

could it be that something is blocking airflow to the engine? that would choke it up for sure.

 

Thanks for all the ideas guys. So it turned out to be a faulty earth connection that caused a fuse to blow. I'll pick up the Jeep tomorrow and then ask the mechanic how he cam to this conclusion...

The diesel we have available here is either 50 ppm sulphur or 500 ppm. And then there is truck diesel. I heard in Europe 5 ppm is available, but not sure about that. I usually fill up at Shell or BP. You have BP over there, but I can't recall seeing a Shell gas station.

 

We have more than a few. Low Sulfur, Ultra Low. When you get up in the colder areas they have special blends for the cold weather. Diesel #1, Diesel #2 and blend. Plus you have variances in how much bio diesel they blend in.