MERCEDES BENZ ML PROBLEMS
Disassembled ML Benz Independent Rear Suspension
Who wants to pay a lot of money for a Mercedes Benz and then find it wasn't as good as expected?
I certainly didn't, and it annoyed me greatly. I must admit to being rather fussy when it comes to motor vehicles.
My name is Ian Stewart and I live in Redcliffe Qld., just north of Brisbane, Australia. My areas of dissatisfaction are as follows:-
I was very disappointed with the ride, steering and general handling of the Benz. The standard KYB dampers fitted in Alabama are very much to American taste and allow vehicle to wallow and bump steer and generally behave in an uncontrolled manner. After much investigation, I found the only alternative is to replace the dampers with Bilstein dampers, made in Europe specifically for these vehicles. These are much firmer in their settings - some would say a trifle too firm. However, the end result is far better :-
No more easy bottoming out of the suspension on moderate bumps.
No more uncontrolled bounce over bumps and through dips.
It now tracks well without bump-steer and is well balanced through a rough corner.
Rebound control is superb.
A further noticeable improvement in ride quality can be had by changing the tyres fitted as standard to the vehicle. The standard tyres are 255/60/17 106H. If they are replaced with narrower 235/65/17, the ride and steering are further enhanced - less tramlining and less impact on joining strips and sharp bumps, whilst still using the recommended 32psi tyre pressure. My research found a suitable tyre - Yokohama Geolander H/T - S in 235/65/17 - 108H. This is a perfectly legal tyre in load and speed rating. Overall gearing is not affected and speedo readings remain accurate. Another cheaper option is with Nexxen tyres of the same size and rating at approx half the price. I got 70000km from the Yokos and have just fitted the Nexxens so nothing to report there for mileage. Good for road noise. I have attached a photo of the Nexxen tyre tread pattern in the gallery. They are mono-directional.
I have experienced quite a deal of trouble with the throttle cable becoming sticky, making it hard to drive smoothly. After a number of attempted fixes from Mercedes Benz, I opted to make up a new cable, using the original outer cable, with a new different inner cable. The original inner and outer cables are both nylon coated and the two nylon surfaces tend to stick to each other. I made up a new inner cable using woven stainless steel with no nylon coating. Problem solved - cost around $65 plus fitting.
ENGINE MODIFICATIONS -
I have found that the diesel engine is very unresponsive off the mark and when driving in cut and thrust traffic situations. Good when on power but too slow to get there. I investigated modifying the engine computer chip and eventually settled for a chip remap from Powerchip Australia. Cost was around $1300. Response was very noticeably improved along with increases in torque and power. Torque increased from 400nm to 495nm and power from 120kw to 148kw, according to their testing. Very different to drive, particularly in traffic. Economy hasn't changed - still averages about 10kpl overall in mixed city/freeway driving. About 8kpl when towing a 1600kg caravan at 100kph where possible. Very satisfactory. Powerchip can be found on the 'net at http://www.powerchipgroup.com.au
As with all modern turbo diesel engines, the inlet manifold becomes full of gunk - a product of EGR gases and PCV gases. If not attended to it will eventually sieze up the swirl flaps in the manifold and also jam up the operation of the EGR. There is an electronic shunt one can wire in which will allow the EGR to be disabled without the ecu being aware of the change and thus not forcing a limp mode. Details are available on this web page -
The use of a space saver is inappropriate in Australia's country areas and particularly when towing a caravan. I bought another full size wheel/tyre and placed it on a vinyl floor covering in the boot. Tied it down using the standard hooks and a strap and built a carpeted hard cover for it. Advantages are two fold. Full sized spare available for use and a place to put your punctured tyre after changing it - it WON'T fit in the space saver holder. Vertical space in the boot is compromised but horizontal area remains. There is enough space beside the box to carry a 39 litre Engel freezer. Works for me. I have placed a photo of the box in the gallery.