Guys so my water pump clearly went out because my R56s's engine was overheating majorly. However, I am skeptical as to whether I need to replace the thermostat.

My car would always trigger lights making me aware of the engine overheating. Does the thermostat regulate that? Because if it does, then that means it is functioning properly. I would rather not go through all of the mechanical work to replace it if not needed.

Thanks in advance.

 

Thermostats on these cars are plastic and tend to crack over time. The early water pump housings were also made of plastic, and would crack. Both of these would result in leaks. If one of these are leaking, I would replace both while you are doing the job.


I don't remember reading or hearing about many overheating issues. The thermostats are fairly complicated (multiple ports and sensors, not just a small metal valve), so I guess it would be possible to malfunction.


Did your car run low on coolant and overheat? If that is the case, there is a bleeder screw on the thermostat. If you just refill the coolant reservoir, but don't bleed the system, there will be problems. Search for 'thermostat replacement' and you should find threads with pictures of the bleed screw.


Give a little more info about your situation and people will chime in with advice. There are several parts vendors that help out on this site as well.


Have fun,
Mike

 

So your check engine light is on? Did you plug into the OBDII to see what P code it's throwing? This code will let you know what is going on with your MINI. Are there any leaks in the system that you can see? The thermostat can start as a hairline crack and pool on top of your transmission. If a fault occurs in the thermostat, a fault code is stored in the ECM, usually with a description of "Map cooling circuit". A fault code can be present yet the vehicle will lack any cooling system issues, such as overheating. This is because the thermostat has a fail-safe mechanical function as well. If you have this fault code, replace your thermostat and bleed your cooling system. Other symptoms of a faulty thermostat are engine overheating, slow to warm up and lack of heat.

When a water pump begins to fail, you'll notice that the car tends to overheat at low engine speed, such as sitting at a stoplight. When you accelerate, the engine temperature will drop. Now, this is not always indicative of a coolant pump failure, but a good starting point. You may also want to try squeezing the top radiator hose with the engine warmed up and running. You should feel pressure build up on the back of the hose and surge once it is released. If you feel no pressure, it's a fair bet that the coolant pump is failing. The most common problem with the electric coolant pumps is a fault code for coolant pump volume.

 

+1 You need to check for leaks on the thermostat, at first when mine went it leaked, no codes, just not hot air in the cabin until it reve'd, then i saw the puddle drip down and the pool of coolant on the transmission housing. The fan tend to run all the time and longer , which is a good indication. Thats all before the major check engine and over heat, Long enough and leaks , then over heat.

Do it all at the same time if the pump is plastic also, saved me a headache down the road.

https://www.northamericanmotoring.co...8-no-heat.html