FAQs—Mercedes Benz ML500
Could a certain type or brand of coolant be used for all vehicles? What's the main difference among different types of coolant?
Although coolants have ethylene glycol as their main active ingredients, they're not made the same. They may contain a different set of additives. They come in different types, and some manufacturers favor or recommend a specific type of coolant over the other. Green coolant/antifreeze is the common type. This coolant comes with additives that protect against corrosion. These additives may be lost after some time. That's why it's often replaced every 2 years or 24,000 miles, or as recommended by the manufacturer. Some other types of coolant have a longer lifespan, a good example of which is the Dexcool coolant. The Dexcool coolant comes in different varieties/formulas but basically have OAT (organic acid technology) additives for corrosion protection. This coolant can be used for as long as 150,000 miles, or depending on the manufacturer's recommendations. However, not all vehicles are OAT compatible. These vehicles may instead use hybrid OAT antifreeze/coolant, which is known to be fast-acting and may last for as long as 150,000 miles. Although this type of coolant may be used as an alternative in case the vehicle isn't compatible with OAT coolant, you should still consult the owner's manual and check the labels to see if this meets the vehicle's requirements.
The Mercedes Benz ML500 surges and misfires. How can I fix this? The engine would start and speed up just fine. As it runs at constant speed, the engine would pick up speed slightly. It would miss and buck. What could be wrong with the engine?
There are more than a few things that need to be checked to figure out why the engine is surging and misfiring. This rough engine performance could be linked to a numerous possible causes, and one of them is a fault in the ignition system. Test the fuel pressure regulator to find out if it's operating at an acceptable pressure. It could also be that the ignition timing needs to be adjusted and set right. The ignition problem may be traced to faulty wires, spark plugs, or other parts. If this doesn't turn out to be an ignition problem, check for a stuck open EGR valve, dirty fuel injectors, or a clogged fuel filter. Also look for a leak in the vacuum lines. It could also be that the torque converter is slipping or its timing is off when locking. Use a scan tool to check any fault in the engine control system and test the compression to gauge the engine condition.
How should I deal with the brake chatter/shudder on my ML500? Any troubleshooting clue?
The brake shudder/chatter could stem from worn-out linings or wobbly or warped rotors. You must check the thickness of the lining to see if it still falls within the recommended measurements. Another thing to look into are the brake drums. The rotors should be checked for excessive wobble or warpage and may have to be replaced to eliminate the brake shudder. Have the drums checked for excessive heat.