I have a 2007 R56. It has about 100,000 miles on it. After shutdown today, the fan kept running for a few minutes (this is normal and has done it since the car was fairly new). The fan sounded fine. However, there was a new fairly loud thumping sound that went at a fairly high rate of speed (about 4-5 thumps a second). It continued for about 90 seconds after shutdown and stopped about the same time that the fan stopped running. It sounded like it was coming from the passenger side of the engine compartment. What do you think. Oil pump? Water Pump? Hopefully not a head gasket. It is not losing any coolant and I checked the oil dipstick and under the oil cap and it does not appear discolored or frothy. I assume that it has something to do with the cars cooling down process because the car ran very normally and I checked for codes and found none. Thoughts?

 

Auxiliary water pump that cools the Turbo after shutdown?

Assuming its the S model you have.

 

"There was a new fairly loud thumping sound that went at a fairly high rate of speed (about 4-5 thumps a second). "

Are you sure this did not come from the back of the car near the fuel tank ? If so the ventilation system in the fuel tanks breath a bit and the tank makes that noise. Like you are talking about.


On shut down the fan should only run a short time ( unless you are running it hard , or a track day ). The Auxiliary water pump( small little pump )also runs a little longer then shuts down its right in front of the transmission, on the driver side. These are on the Turbo engines. There was a recall on these for new ones, if your MINI was part of the recall.

That sound is coming from the passenger side? Can you post up a video ?

 

its the fuel tank pressure relief valve, normal