WIS 20.00 General

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M113 Engine Cooling System

Coolant Diagram - M113 Engine Cooling System

Issues - M113 Engine Cooling System

• OEM Coolant is supposedly good for 250,000Km or 15 Years.
• M-B DIY enthusiasts typically change the coolant every 3 - 5 years.
• For other issues such as leaking hoses and pipes see WIS 20.20 Radiator, Coolant Hoses.

Parts - M113 Engine Cooling System

• Cooling System Capacity is 11.2L.

Part Number Coolant Anti Freeze Types

• BQ 1 03 0002 (G05) yellow M-B Sheet TBD
• BQ 1 03 0004 (G48) dark blue/green M-B Sheet TBD
• BQ 1 03 0005 (G??) pink M-B Sheet 325.5

M-B Article on Engine Coolant BQ 1 03 0005 (G48)

http://www.benzworld.org/forums/w211-e-class/2209257-rust-water-pump-hint-failure-coolant.html?utm_medium=email&utm_source=201#post10680497

DIY Basic Coolant Change - M113 Engine Cooling System

This is the basic DIY Coolant Change Technique for Flushing and Refill:

• ONLY open the system with engine temperature less than 90C, and do it SLOWLY.
• Drain old coolant using Radiator Drain Plug (and engine block drain plugs if they exist).
• Dispose of the Coolant per your Local regulations, even though it is classified as "Biodegradable".
• Fill with rain water using Vacuum Filling System to remove trapped air bubbles. (Takes about 6-7L.)
• Drain again.
• Repeat fill with rain water and drain several more times until drained fluid is clear. (On last few drains, use Vacuum System without filling to remove deep trapped air bubbles.)
• Then fill with distilled water using Vacuum Filling System. (Takes about 6-7L.)
• Drain once more. (Use Vacuum System several times without filling to remove deep trapped air bubbles.)
• If using M-B coolant add as much as system will take using Vacuum Filling System.
• If using antifreeze concentrate add 6L of concentrate using Vacuum Filling System.
• Top up with distilled water.
• After all air has escaped top up with either M-B coolant or distilled water as required.
• Final Concentration using antifreeze concentrate should be 6L in 11.2L ie 54%.
• Note if you do a "complete" coolant change every 2 - 3 years, there is probably no need to do the several rain water and distilled water flushes.

DIY Radiator Coolant and Pressure Test - M113 Engine Cooling System

This is the thorough DIY Coolant Change Technique for Flushing and Refill:

http://www.benzworld.org/forums/w140-s-class/1444114-photo-diy-coolant-service-la-vacuum.html

Temperature Sensors - M113 Engine Cooling System

TBA

Here are some typical M-B thermistor resistance values made at a given temperature. The tests were conducted on a W204 2008 C220 but are representative of all M-B Thermistors.

• Temperature sensor near the water pump (A311 01:09) with a green dot at 18°C it had a resistance of 2.36K Ohms. When warmed slightly with a heat gun the resistance dropped to 1.48K Ohms.
• Temperature sensor in the thermostat housing (B11/4) at 18°C B11/4 had a resistance of 2.81K Ohms. When warmed slightly with a heat gun the resistance of B11/4 dropped to 1.15K Ohms.