[BimmerBoy007]

I am having problems with my car overheating. Ive scanned the car and also had it diagnosed at an bmw Indy shop. For some reason no codes are popping up stating water pump failure but the connector is corroded and damaged. They are wanting to replace the whole water pump for $1200 but i do not think that is the problem. I am planning on replacing the connector with another pig tail from junkyard by cutting old one and splicing it in. Bmw unfortunately does not selll this unit by itself. Does anyone have any experience or insight on this?

[n55david]

Originally Posted by BimmerBoy007

I am having problems with my car overheating. Ive scanned the car and also had it diagnosed at an bmw Indy shop. For some reason no codes are popping up stating water pump failure but the connector is corroded and damaged. They are wanting to replace the whole water pump for $1200 but i do not think that is the problem. I am planning on replacing the connector with another pig tail from junkyard by cutting old one and splicing it in. Bmw unfortunately does not selll this unit by itself. Does anyone have any experience or insight on this?

if you're over 60k miles just do the water pump. 1200 is a bit much though. I paid 835 including 6% sales tax for the waterpump and thermostat on the x3 and its the same thing.

[BimmerBoy007]

Yes I’m contemplating just doing the water pump but I’m not having any codes being thrown and can see the coolant flowing through overflow tank when the top is off so I’m not understanding why my engine is over heating. And the Indy shop i went to was definitely over priced. $800 sound more reasonable.

[n55david]

Originally Posted by BimmerBoy007

Yes I'm contemplating just doing the water pump but I'm not having any codes being thrown and can see the coolant flowing through overflow tank when the top is off so I'm not understanding why my engine is over heating. And the Indy shop i went to was definitely over priced. $800 sound more reasonable.

I had no codes either

[F32Fleet]

Originally Posted by BimmerBoy007

Yes I'm contemplating just doing the water pump but I'm not having any codes being thrown and can see the coolant flowing through overflow tank when the top is off so I'm not understanding why my engine is over heating. And the Indy shop i went to was definitely over priced. $800 sound more reasonable.

The vehicle has various operating profiles and either the pump is unable to keep up or the thermostat is getting lazy.

[thejeremyman9]

Let me ask this question - how do you know you are overheating? What coolant temps are you seeing? Are you getting warning messages?

[BimmerBoy007]

Originally Posted by F32Fleet

The vehicle has various operating profiles and either the pump is unable to keep up or the thermostat is getting lazy.

Yes i am having my pump replaced tomorrow hopefully this will fix the problem. I will update.

[BimmerBoy007]

Originally Posted by thejeremyman9

Let me ask this question - how do you know you are overheating? What coolant temps are you seeing? Are you getting warning messages?

I stared receiving engine temp warning then few minutes later engine over heating will driving just a few miles from home. This all happened the day after I changed the spark plugs, before then never had any engine temp warning. Also i have tracked my temp using bimmer link at around 115c when i get the warnings.

[thejeremyman9]

Originally Posted by BimmerBoy007

I stared receiving engine temp warning then few minutes later engine over heating will driving just a few miles from home. This all happened the day after I changed the spark plugs, before then never had any engine temp warning. Also i have tracked my temp using bimmer link at around 115c when i get the warnings.

Yeah that's a little high, but i have seen around 110c/230F under normal driving before.

From the N55 engine manual:

Engine cooling
The engine cooling system utilizes an electric coolant pump. The heat management determines the current cooling requirement and controls the cooling system accordingly. Under certain circumstances, the coolant pump can be completely switched off, e.g. to rapidly heat up the coolant during the warm-up phase. The coolant pump continues to operate when the hot engine is shut down. The coolant capacity can therefore be varied regardless of the engine speed. In addition to the characteristic map thermostat, the heat management makes it possible to use various characteristic maps for controlling the coolant pump. In this way the engine control unit can adapt the engine temperature to the driving conditions.

The engine control unit regulates the following temperature ranges:
• 108°C/226°F = Economy mode
• 104°C/219°F = Normal mode
• 95°C/203°F = High mode
• 90°C/194°F = High mode and control with characteristic map thermostat

The engine management sets a higher temperature (108°C) when, based on vehicle operation, the engine control unit detects ”Economy” mode. The engine is operated with relatively low fuel requirements in this temperature range. The internal engine friction is reduced at higher temperatures. The increase in temperature therefore results in low fuel consumption in the low load range. The driver wishes to utilize the optimum power developed by the engine in “High and control with characteristic map thermostat” mode. For this purpose, the temperature in the cylinder head is reduced to 90°C. This temperature reduction promotes improved volumetric efficiency, thus resulting in an increased engine torque. Adapted to the relevant driving situation, the engine control unit can now regulate a defined operating range. In this way it is possible to influence the fuel consumption and power output through the cooling system.

System Protection
If the coolant or the engine oil overheat during operation, certain vehicle functions are
influenced to the effect that more energy is available to the engine cooling system.

These measures are divided over two operating modes:

• Component protection
- Coolant temperature between 117°C/242°F and 124°C/255°F
- Engine oil temperature between 150°C/300°F and 157°C/314°F
- Result: The output of the air conditioning system
(up to 100%) and of the engine is reduced

• Emergency
- Coolant temperature between 125°C/257°F and 129°C/264°F
- Engine oil temperature between 158°C/316°F and 163°C/325°F
- Result: The power output of the engine is reduced
(up to 90%)

[BimmerBoy007]

Originally Posted by thejeremyman9

Yeah that's a little high, but i have seen around 110c/230F under normal driving before.

From the N55 engine manual:

Engine cooling
The engine cooling system utilizes an electric coolant pump. The heat management determines the current cooling requirement and controls the cooling system accordingly. Under certain circumstances, the coolant pump can be completely switched off, e.g. to rapidly heat up the coolant during the warm-up phase. The coolant pump continues to operate when the hot engine is shut down. The coolant capacity can therefore be varied regardless of the engine speed. In addition to the characteristic map thermostat, the heat management makes it possible to use various characteristic maps for controlling the coolant pump. In this way the engine control unit can adapt the engine temperature to the driving conditions.

The engine control unit regulates the following temperature ranges:
• 108°C/226°F = Economy mode
• 104°C/219°F = Normal mode
• 95°C/203°F = High mode
• 90°C/194°F = High mode and control with characteristic map thermostat

The engine management sets a higher temperature (108°C) when, based on vehicle operation, the engine control unit detects ”Economy” mode. The engine is operated with relatively low fuel requirements in this temperature range. The internal engine friction is reduced at higher temperatures. The increase in temperature therefore results in low fuel consumption in the low load range. The driver wishes to utilize the optimum power developed by the engine in “High and control with characteristic map thermostat” mode. For this purpose, the temperature in the cylinder head is reduced to 90°C. This temperature reduction promotes improved volumetric efficiency, thus resulting in an increased engine torque. Adapted to the relevant driving situation, the engine control unit can now regulate a defined operating range. In this way it is possible to influence the fuel consumption and power output through the cooling system.

System Protection
If the coolant or the engine oil overheat during operation, certain vehicle functions are
influenced to the effect that more energy is available to the engine cooling system.

These measures are divided over two operating modes:

• Component protection
- Coolant temperature between 117°C/242°F and 124°C/255°F
- Engine oil temperature between 150°C/300°F and 157°C/314°F
- Result: The output of the air conditioning system
(up to 100%) and of the engine is reduced

• Emergency
- Coolant temperature between 125°C/257°F and 129°C/264°F
- Engine oil temperature between 158°C/316°F and 163°C/325°F
- Result: The power output of the engine is reduced
(up to 90%)

Thanks for this! Yes when my car was getting diagnosed they said at one point it reached 120C. Ive also noticed that my heater is not working at all and was perfectly fine before car started over heating that is why I’m assuming it is the water pump.

[BimmerBoy007]

Just wanted to update, after water pump was replaced car stopped over heating. Thank for all the help!