Hello,
The first thing to do is to inspect the engine for any possible leaks. If you do not see coolant leaking then open the resevoir cap and check the fluid level of the coolant. Most likely you will find that it is low. You will need to use blue coolant (ethyline glychol) that has been mixed to a 50/50 concentrations with water. There is a small plastic screw on the resevoir tank. Remove the screw and fill the resevoir slowly until it runs out of the plastic screw hole, then re-install the screw carefully as not to overtighten. Then run the vehicle with defrost on high and check for heat. Make sure the engine temp does not overheat. If it starts to, let it cool and then check the coolant level again and add more if it looks low in the same way and repeat untill you have heat. All the while checking for any signs of a leak.
Let me know how it goes and I will try to help you further. Please accept if this has been helpful. Thank you.
Hello XXXXXXXX,
The drain plug for the block is on the passenger side of the block and really only accessable from underneath the vehicle. I have a general picture of the area. If you would like, instead of accessing the drain on the block you could use a hose and run clean water through the engine and leave one hose disconnected to flush the block out. Then drain as much as you can and refill. The coolant mix should still be fine with the water in the block and it would be easier. But if you want to drain the block make sure if there is a copper 0 ring washer it will need to be replaced with the same size washer made of copper. It must fit the bolts diameter perfectly to prevent leaking.
Please let me know If I can help you further.
BMW Mechanic
Level 1 BMW Master Certification, 9 Years Dealer experience, Team Leader, Shop Foreman
Hello IRobot,
I can understand you concern. After you flushed with water did you drain the radiator again before adding fresh coolant?
Hello Irobot,
I have been trying to think of a way for you to get a better flush of the system. Unfortunately I think to truly get a good flush on one shot the block would have to be drained along with the resevoir tank and radiator. My only suggestion is to do a series of flushes. This would at least lead to better anti-freeze protection and also help clean out the system of the old fluid. It is not perfect but it might help in the long run. Some shops have a machine that hooks up to the coolant hoses and can then flush the entire system without having to even drain the coolant out as it captures it. To do it yourself though, you could do a series of radiator flushes until you reach the end of the gallon of antifreeze. I hope this helps you to decide on how to proceed. It is amazing how little a radiator actually holds.