Notes for working on the cooling system (M4 2021-2023): Notes
WARNING: This page is about a different car, the 2025 BMW M4, 2024 BMW M4, 2023 BMW M4, 2022 BMW M4, and 2021 BMW M4. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Risk of scalding: only carry out repairs on the cooling system after the engine has cooled down!
IMPORTANT:
Wear hand protection and safety goggles.
IMPORTANT:
Service life coolant filling:
Never reuse used coolant!
When replacing and removing components which rely on the corrosion protection effect of the coolant, it is essential to change the coolant. The cooling system must therefore be drained and refilled.
In the case of other removal work involving the draining of part quantities of coolant, replace these quantities which have been drained with new coolant.
Never reuse used coolant!
When replacing and removing components which rely on the corrosion protection effect of the coolant, it is essential to change the coolant. The cooling system must therefore be drained and refilled.
In the case of other removal work involving the draining of part quantities of coolant, replace these quantities which have been drained with new coolant.
Installation note:
Use ONLY RECOMMENDED COOLANT .
Observe MIXTURE RATIO .
IMPORTANT:
Open cooling system only when it has cooled down.
Opening the cooling system while hot can result in air entering the system.
This can cause overheating with permanent damage to the engine.
Opening the cooling system while hot can result in air entering the system.
This can cause overheating with permanent damage to the engine.
IMPORTANT:
You must protect the alternator against dirt contamination before carrying out any repair work on the coolant circuit.
Cover alternator with suitable materials.
Failure to comply with this procedure may result in an alternator malfunction.
Cover alternator with suitable materials.
Failure to comply with this procedure may result in an alternator malfunction.
IMPORTANT:
Do not fill coolant expansion tank over maximum level, as overfilling will cause the coolant to overflow. This may give rise to traces of coolant on the expansion tank or in the engine compartment and wrongly suggest possible leaks.
Recycling
Catch and dispose of drained coolant.
Observe country-specific waste disposal regulations.
NOTE:
To disconnect coolant hoses, use commercially available disconnection tools such as HAZET brand tools (see table below).
| HAZET number: | Description |
|---|---|
| 4590-1 | Length of disconnect pliers (mm): 150 |
| 4590-2 | Length of disconnect pliers (mm): 180 |
| 4590-3 | Length of disconnect pliers (mm): 253 |
| 4590/2 | Set of clamping pliers |
| 4590/3 | Set of clamping pliers |
Set of special tools 17 2 050 for removing and installing the spring holder clamps for coolant hoses.
- Release tool.
- Pliers (bent version).
- Pliers (straight version).
Loosen spring strap (1) with the pliers (2).
Unlock spring strap (1) with the release tool (2).
NOTE:
Tightening torque for hose clamps
| WAF 5 | 1.0 - 1.5 Nm |
| WAF 6 | 2.5 - 3.5 Nm |