I found a 2010 ML350 Bluetec Diesel that has a clean carfax history, 30 service records, 2 owner, and 131k miles. I've not physically looked at the car yet...but the 131k miles was the only thing that gave me pause.

However, that isn't a big deal to me if the vehicle has performed well the entire time and has routinely been checked. However since I don't know much about Mercedes engines and hardware...I don't know if 131k miles is still a decent number, or I need to start worrying.

I have a 2006 ML 350...and it has 181k miles...however, our particular model has had a series of hiccups over the years with check engine lights so I don't feel that is a good comparison.

Thanks

 

According to mechanics from Russia early engine seizure is due to inaccurate work on oil cooler leak service. Dirt gets into the turbo oil channel on the engine block which eventually messing up your crankshaft bearings.
Some of the Sprinters with same diesel engine run up to 500k miles before rebuild.

 

Stay away! Even if oil cooler seals have been replaced properly, diesel particulate filter & selective catalyst reduction via diesel exhaust fluid will be sure to give issues & frustration when price to repair these elements is discovered. DPF regens will allow diesel to dilute engine oil & sludge up motor, even worse stretch timing chain. All very expensive repairs. Sprinters have a 13 quart oil pan & far better air filters than ML which has a 9 quart oil pan & substandard air filters. I drive a 2007 ML & it has 186k miles. It has DPF but no SCR or DEF. I change oil every 5k & oil filter every 2.5k, air filters I blow out w/ compressed shop air every 5k miles & replace @10k. Try to find one w/o bluetec if you really want one.

 

Mercedes has lots of problem with the Bluetec. Go with something else. But I have my E350 Bluetec and have not had problems. But it requires careful attention to work out well. Using a proper oil and keeping everything operating in specification. Yes you will have to clean the inside of the inlet air system and the EGR system... as they carbon up. But generally I have had good service. But I drive it more like how I fly a modern airplane... !
But understand the engine operates in most modes with high level of exhaust gas recirculation. Well this is hard to measure precisely without specialized lab equipment. But the car does a pretty good job of estimating... the car ECU calculated the actual flow from position of the EGR valve and mass air flow into the inlet. They did tests in the lab during development to discover the actual EGR mass flows and then in the ECU created an algorithm to calculate with fair accuracy the percentage of EGR to inlet flow, and to also so the actual mass flow rate to the inlet.
The EGR works like a throttle. Some numbers at a constant 75 mph on flat ground today manifold pressure 1160 mpa, ambient air pressure 966 mpa, percent of total inlet flow of EGR 74%, going up long hill 1220-1250 mpa manifold pressure, ambient air pressure 966 mpa, EGR -60% of total inlet flow, and total EGR going down long hill 40% . DEF loading 4% at beginning, 4% at end of 52 mile run, fuel milage average 37 mpg. My DEF has never exceeded 20 %, but mostly stays very low in the less than 10% and mostly less than 5%. No sludge in oil or crankcase/sump/valve covers. Some moderate soft carbon soot buildup in inlet manifolds and EGR plumbing... due for cleaning. The only beyond routing maintenance has been replacing the MAF sensors... actually the air horn with the left and right MAF sensors... I cleaned them... this puts them out of calibration... you then have to buy a whole new air horn sensor assembly that has been balanced calibration... don't clean... just keep air clears replaced often. I have seen in the middle 90% EGR of total inlet flow!!! You will find lowest level of EGR at idle with around 0%. But my engine in leak down runs less than 5% - excellent and the cylinder bores has not been polish. Oil changes every 5000 miles with filter, first 25,000 miles Mobil ESP synthetic 0w-30 synthetic 229.52. Since 25,000 Shell Rotella T6 5w-40... no problems.

 

Run away! Buy a gas model if you like the ML's.