The trusty Jeep 3.0 V6 Diesel engine is actually a motor borrowed from Mercedes Benz. As such this particular fault is applicable to all engines with the code OM642.
A common issue with these V6 diesels is oil leaking from the oil cooler. The result of this fault is oil leaking onto the ground, this could result in rego failure, low oil warning lights and a general mess around your engine.
The fun part of this job is the actually location of the oil cooler. The repair itself is not a major issue as its less that one hundred dollars worth of replacement seals to get the fault sorted. However a minimum of ten hours labour is required to get the job done.
The oil cooler is located in the valley of the V. To access this the inlet manifold needs to be removed and to to get to that the turbo has to come off. The Jeep workshop manual states that to remove the turbo from engine the transmission has to be removed. Our Jeep specialist informs us that it can be done without removing the transmission but the task becomes a bit fiddly.
Once in the valley the cooler itself does not need replacing. Most of the time the fault is just the seals in the cooler. Replacing them is fairly straight forward once you’re in however you now have to put it all back together.
Many people suggest this fault only occurs on vehicles released before 2010, however this seems to be inaccurate information. Several vehicles with engines manufactured after this date are presenting with this fault.
The long and the short of it, this is not a job for the lighthearted, nor is this a DIY in your back yard on the weekend kind of Job. This is something best left to those who know what they are doing.