PeachParts Mercedes-Benz Forum - View Single Post - Considering a 2007 ML320 CDI, known problems ? advice ?

jay_bob · #3 02-12-2014, 08:57 PM

We have had a 2008 ML320 CDI since July. This is essentially the same vehicle as a 2007, and I would recommend you consider 2008s as well, since they do not use AdBlue either (that started in 2009 for the ML320s).

The car we purchased came from our local MB dealer in town. This was a local car, as verified by carfax and the prior owner's info on the VMI copy the dealer showed me. (He let me keep a copy for my records after redacting the PO's info.) The car had been meticulously maintained at the dealer every 10 k per schedule and had very few issues while it was on warranty. It had 106k on it when we bought it and we are now up to 113k.

I think the PO decided to trade it in when the catalytic filter got plugged, and I think the owner did not want to spend 3k to get it replaced at the dealer. The dealer replaced it before putting it up for sale. If you are looking at a model with near 100k miles, I would check to see if that cat has been replaced.

The good:
It feels like it will power through anything. We call it "the beast".
Great highway cruiser, returns mid 20s MPG on Diesel. Gas powered models take premium unleaded (which is within a few cents of Diesel here) and return mid-high teens.
Interior well put together but you can definitely tell the bean counters got after the engineers for cost reductions.
Does not require AdBlue, so you do get a spare. Unfortunately it is a compact spare.
Has plenty of room in the second row as long as the front seat passengers do not have the seats all the way back. I am 6"3' and have plenty of headroom and the seat is only back about 90% of the way.

The warts:
Audio system sounds great, and has near competition levels of bass available, but the Bluetooth and iPod integration is just not up to today's standards. It works but it is not as slick as the modern units. No A2DP support (to be fair, that wasn't released in the mid 2000s when these cars were designed). The navi works but again it's clunky compared to modern units. Negotiate with the dealer for a new navi DVD, they are several hundred dollars.
Power tailgate can be cranky. Sometimes it goes up by itself, sometimes not. I think the system is getting weak because if I give it a helping hand on opening, it will finish by itself. It is very complex and uses a hydraulic pump buried beneath the floor board to operate a cylinder in the roof.
Tires: The stock tires are 19" ($$$$) and you can count on having to replace the TPMS sensors. I had to replace the tires, a set of Contis were $995 out the door, and I bought the TPMSs online for another $260, and gave them to the tire guy to put in while he had the rims open.
Maintenance: The dealer will kill you with oil changes. DIY is not too bad especially with a topsider. However you must use only "Mobil1 ESP Formula M 5W40" and it takes 9 quarts at ~$12/quart. Oil every 10k, fuel filter every 20k.
Trans fluid: Manual calls for one time at 40k then you are "good for life", well we know what that means if you have a W210 or later with the 722.6 transmission. I would recommend fluid changes at least every 50k after that. It takes a special MB fluid that is mandatory for this transmission and it too is in the teens of dollars/quart. It takes 9 quarts and the procedure is complex as there is no dipstick to check the fluid level.
Systems complexity: If you are used to an IDI engine (aka OM61x or OM60x) you will be in for a huge surprise. The OM642 looks like the space shuttle main engine in comparison. Others on the forum call it the "rubber band ball".
Fuel cleanliness: Because it is a CDI, water or contaminants in the fuel are fatal to the injectors. For this reason you have to be picky about where you buy fuel. The fuel filter does have a water separator built in.

Even with all that I would recommend purchasing one that has been well maintained and has complete service records.