2006 BMW 330i Water Pump Replacement

2006 BMW 330i over-heating problem & water pump replacement. The customer reported that the vehicle was overheating and leaking coolant. The customer added coolant, drove the vehicle to the shop, and requested a cooling system pressure test and inspection for a coolant leak. The customer also said the vehicle had a recent water pump replacement and heater core flush at another auto repair shop.

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Diagnosis

We pressure-tested the cooling system and found no external coolant leaks.

The coolant system pressure test found the system held specified pressure with no pressure loss. No visible coolant leaks were found.

Next, we did an engine management computer scan and found an error code indicating the water pump was not operating. The 2006 BMW 330i has an electrically driven water pump so we tested the water pump's electrical supply and found the pump was receiving the correct electrical power and control signals. A computer scan found an error code showing a break in the water pump's internal wiring. This meant that the recently replaced water pump had failed. Since the pump is not repairable the vehicle required another water pump replacement.

This is rare for a new water pump to fail so the technician continued the diagnosis to find the reason for the second coolant pump failure.

The engine management computer scan showed an error code for the water pump. See the second line which is highlighted. The "missing" comment means there is a break in the water pump's internal wiring which is not repairable and requires water pump replacement.

Our BMW technician also noticed that the metal coolant pipe to the water pump was crushed, which would restrict coolant flow. This possibly happened during a previous engine replacement, or during the previous water pump replacement, at a different auto repair shop. The damaged pipe restricted the coolant flow and most likely caused this 2006 BMW 330i water pump failure.

Our technician also noticed a damaged coolant expansion tank cap. Notice the broken and missing ring of plastic around the yellow center. This is caused by age and the cap should have been replaced a long time ago. The plastic deteriorates from the high heat of the cooling system and starts to crumble and fall apart. Those pieces fall into the cooling system and can block the radiator, heater core, and coolant passages inside the engine causing overheating. The broken pieces may also have damaged the water pump and caused it to fail.

Notice the broken and missing ring of plastic around the yellow center of the coolant expansion tank cap. This is caused by age and should have been replaced a long time ago. The plastic deteriorates from the high heat of the cooling system and starts to crumble and fall apart. Those pieces fall into the cooling system and can block the radiator, heater core, and coolant passages inside the engine causing overheating. The broken pieces can also damage the water pump.

Only an experienced BMW technician would have noticed the crushed coolant pipe and coolant expansion tank cap problems. Replacing the water pump without replacing the damaged coolant pipe and coolant expansion tank cap would probably have resulted in continued engine overheating problems and water pump failure again.

Cause

The water pump had recently been replaced and failed again. Replacing the pump without finding and replacing the damaged coolant pipe would have only resulted in the pump failing again. We suspect the restricted coolant flow from the crushed coolant pipe caused the water pump to run non-stop, placing excessive load on the pump and causing it to overheat and fail quickly. Once the coolant pump failed the engine would run hot and overheat. The coolant restriction may also explain the lack of passenger compartment heat and the other repair shop recommending a heater core flush. Replacing the water pump and flushing the heater core did not solve the actual problem.

Skilled BMW technicians and good diagnosis is our secret to providing value for our customers.

Repair

Water pump replacement, coolant pipe replacement, coolant expansion tank cap replacement, cooling system flush, coolant replacement, clear computer error codes, and confirmed over-heating problem solved. Extracting the previously broken water pump mounting bolts complicated the repair.

Cost

How much does it cost to replace a water pump on a BMW 330i?

A national average for BMW 330i water pump replacement cost estimate ranges between $800 and $900. Price will vary greatly depending on age and condition of the vehicle and other related problems.

Cost to repair this vehicle was significantly more than the average basic water pump replacement price due to the additional diagnostic time to find multiple problems, additional repair procedures, and additional parts required.

But this vehicle was diagnosed and repaired correctly. Something other shops were unable to do. Stadium Auto Service specializes in BMW repair and service. Your BMW gets fixed correctly. And you get great value.

Tips

• Find an auto repair shop that listens carefully to the problem the customer is having with their vehicle. Find a shop that has auto service technicians who have experience with your vehicle make and model. And find a technician who will not jump to conclusions. Auto repair problems can often be complicated!

• BMW cooling system maintenance is very important.

• The average BMW water pump life is approximately 80,000 miles. More if regular maintenance is done. Less if regular coolant replacement is not done.

• Be very careful with engine over-heat problems. Overheating can quickly destroy the engine. If this problem had happened during the summer, the engine probably would have been ruined.

Contact Stadium Auto Service for all BMW services and repairs in Ann Arbor, MI.