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)
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:
Temperature Sensors - M113 Engine Cooling System
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.