
How to Diagnose, Read, Reset Mercedes-Benz Fault Codes & Lights
In this guide, we take a look at how to diagnose Mercedes-Benz cars yourself.
In this guide, you will find step-by-step instructions on how to change a Mercedes-Benz water pump.
This guide's instructions apply to M112, M113, M272, and M273 engines found on many models, including C, E, S, CLK, ML, GL, SLK, CLS, G, R class, etc.
Removing the radiator cooling fan is recommended so that you can have more room to work. The fan is straightforward to remove. Disconnect the wire harness remove the clips or bolts that secure the fan to the radiator, and pull the cooling fan shroud up.
You must verify Mercedes water pump torque specifications by calling your dealer. Torque values vary between engines. The values below are for M112 and M113 engines.
Alternator bolt | 40 Nm |
M6 Bolts (not pre-tapped) | 15 Nm |
M6 Bolts (pre-taped) | 10Nm |
M8 (Not pre-tapped) | 35 Nm |
M8 (pre-taped) | 25Nm |
Idler Pulley | 10 Nm |
The easiest way to check for a bad Mercedes water pump bearing is to use a mechanic's stethoscope and check for noise near the water pulley.
A common symptom that your Mercedes water pump is bad is the engine overheating or coolant leak at the front of the engine. Water pump symptoms develop overtime before the pump completely fails.
One way to check if your water pump is failing is to remove the serpentine belt and check the water pump for play and inspect for coolant leaks. You can start the engine for up to one minute to determine if the engine noise is gone without the water pump running.
Do not continue to operate your car if the water pump fails. If you continue to drive your Mercedes-Benz, you risk causing severe damage to your engine, including blowing the head gasket, cracking the cylinder head, or seizing the engine. All these are costly repairs and, in some cases, may require the engine to be replaced entirely. If your Mercedes water pump fails, it is better to get the car towed than risk causing additional engine damage.
The water pump's primary purpose on your Mercedes-Benz is to circulate the coolant in your engine's cooling system. The most common symptoms of a failed Mercedes-Benz water pump is the engine overheating or a small coolant leak.
Mercedes-Benz water pumps suffer from two main issues.
When the seal fails, it will cause the coolant to leak. If the bearing fails, it will cause abnormal engine noise. Below is a list of possible symptoms caused by a bad Mercedes water pump.
By YOUCANIC Automotive Experts Published on: Thursday, July 26, 2018. |