I'm looking at buying a W163 this weekend so I've been reading a lot of threads in MBWorld to find the weaknesses of the W163 ML. I've even spoken with the the service advisers at my local MB dealerships and independent shops to gain a better idea of what goes wrong with these vehicles. I know that buying a MY 2000+ will save me from many of the problems which plagued the 98-99s, and the facelift of 2002 brought even more improvements and an upgraded interior.

What remains unclear (as I couldn't get a definitive answer from anyone) is which specific problems were fixed with the 02 MY facelift and what problems occurred only after the facelift? Can anyone clear this up?

Another fuzzy area is which engine is more reliable, the 350 or 500? Both the dealer and indy said they are very good engines but I'd like to hear your experiences. The dealer mentioned that the transmission is the weak link of this ML chassis but MY 2000+ are slightly better. The indy said the transmissions are solid units IF the services were done on time.

I have tested the 500 and I love the power it has. Wind noise is noticeable at highway speeds but it isn't too bad. I want to drive a 350 to see if I can detect a distinct power difference between the V8 and V6. I would imagine that fuel economy is about the same since the V6 has to work harder.

Anyway, your advice is much appreciated.

 

We had a 2001 ML430 for a few years and it was a great truck, but did have a few issues of the earlier models most notably the fuel sender which required replacement of the whole pump/sender assembly. It had a few other less serious things, but they all happened and were corrected while it was still under warranty. The power with the V8 was excellent and no matter how much you asked of it, it never seemed to have to work very hard at all. We got around 13-14 around town and 18-20 on highway trips, the best coming back to VA from WI. Got to about 90k miles and sold it.

About a year later we got a 2004 ML350. Had to replace the alternator and water pump at around 65k. Other than that, no big issues. Around town mileage is better at 17-18, but highway only seems to be a little better than the 430 at 20-22 and doesn't seem to be as effortless. In all fairness, we've not taken a truly long road trip in it as we did in the 430, so it may do a little better.

The 430 had NAV standard, but the newer 350 has opening rear vent windows, which are nice. I love the interior space with the seats down, we are always surprised at what we can get into it. We're at about 90k on the 350 now, and it seems to be doing just fine. Never had any drivetrain issues with either. With all other things being equal, I would probably find the cleanest, newest 500 I could find over the 350. To me, the extra torque and seeming lack of effort in producing it would be worth the extra fuel. YMMV

Happy hunting!

 

Yeah, I was almost shocked when both the dealer and Indy shop said that the W163 was a good car for the most part. I had heard that it was one of the worst products to ever come off a Mercedes-Benz assembly line. Paul, in your experience, is the difference in power ALWAYS noticeable or is it evident only when on the motorway?

 

I'm a self-confessed torque addict, so I feel it all the time. In fairness the 350, even our '04, IS much better than the old 320 in terms of power. I just admired the way the V8 moved the thing around so effortlessly. On the highway, I suppose the aerodynamics of the thing likely comes into play and the extra power is welcome there. Our MLs have both been primarily my wife's to drive and she doesn't seem to be as bothered about the missing power. As you drove the 500 first, your perspective may now be skewed!

 

I know where you're coming from, I currently drive a Saab 9-5 Aero with 260 ft-lbs of torque at 1500 rpm and now I'm addicted. The amount of torque and where it comes on in the power band is a big determining factor when buying a car.

 

What about this issue with catalyitic converters being prone to failure on the W1163?

Is this issue specific to a model year?

Does it happen more frequently with the V6 or V8?

Is there a permanent fix?

 

I drove an ML350 tonight. It has adequate power but the difference between the 350 and 500 is quite noticeable to me. I think if I could find a 350 that was optioned with the M2 package, I would get it.

Does nobody have and answer to my question about the catalytic converters?

 

We received a letter about the cats on our '01 ML430 saying they'd be replaced if faulty, had it inspected on my next dealer visit and they were fine. Never heard anything about the '04 and have had no issues with cats on either.

 

I replaced my cats @ 110k miles but did it because they rattled when i hit them, probably could have lasted a little longer. The truck was also 10 years old at the time. I think thats pretty good lifespan. I replaced the precats with Hi flow Magnaflows, deleted the secondary Cats, Deleted the resonator and replaced all 4 o2 sensors at the time. Local SPeed shop did the whole job for $800, since he priced matched all the prices I got online, and charged me $300 for labor which was included in the $800 (parts were 2 Cats, MAgnaflow y-pipe to replace the rez, and 4 OEM o2 sensors), which I thought was a great price. Truck Sounds awesome now, and feels like i gained a little power, which may have been due to replacing the old cats and o2 sensors. I was very pleased. This was on my 01 ML55 AMG.

 

I have an '02 ML500. Now at 150k miles, started at 78k miles. One of my considerations was towing, so I went with the bigger engine. I would think the 350 would be adequate for almost all other situations.

If fuel efficiency (note I did not say ECONOMY ) is a consideration, 350 is the way to go. The cars up to 2001 had a 3.46 ring and pinion, '02 and later had 3.70. Helps acceleration, affects fuel efficiency.

The 500 motor has been around a long time and is well sorted. Likewise, the 350, is used in a lot of vehicles. It is the older car electrics that act up, not the motor.

I service the tranny about every 50k-60k miles. Full flush, including the torque converter. If not, cut your interval in half. It is very cheap insurance to help insure long life on the tranny.

I have added some headers and chip tuning, as well as taller gears to get 350 like fuel efficiency. 15-16 in mixed driving, 19 or so on the highway (keeping it around 65 will yield about 20 mpg).

The SUV has been relatively trouble free in 6 years and 70+k miles of owenship. Biggest pain has been replacing the brake light switch. Hopefully, that is fixed with the most recent recall for "cruise control". I had to do a water pump which let go, replaced the coolant overflow reservior, and did a power steering hose (which was later subject to recall). Other than replacing shocks for wear, not much other unusual maintenance items.

No issues with the cats. If they go, you can have them rebuilt or swapped for a generic for a fraction of the price of what MB would want.

I find this to be an excellent all around vehicle. I love its compact size. It has plenty of room inside, without the length of some of the bigger cars (Suburban, Excustion, etc). With the third row seats, I can carry extra passengers without the bulk. The only compromise is I can't take extra passengers AND extra cargo. Hasn't been an issue yet.

All things being equal, the newest/lowest mileage is best. When I searched I decided on '02 or newer. At least in my case, it has worked out well. YMMV.

Regards,
Jerry

 

That's great news Jerry, thank you very much. I've actually decided that the ML350 isn't quite good enough for my preferences so the ML500 is the way to go for me. I never tow anything but I like the urgency with which the V8 responds to my foot. I'm excited to get my ML, I just have to sell my car first.