1999 BMW 328i (E46) – Coolant Hose Replacements Part 2

Hey guys,

back here with the second episode of the coolant hose replacement ordeal here on the 328i. I guess before we go any further it’s probably a good place for me to make a disclaimer. It would really be better if you’re refreshing the coolant hoses on a E46 BMW, that you remove the intake manifold before doing the hoses. It makes the process much easier and the plastic hoses underneath usually need replaced anyway. As I said before, we thought we could take a shortcut and skip changing those plastic hoses but it will be revealed soon that that was a bad idea, the other reason we didn’t remove it here was I didn’t order a replacement gasket and O-rings for the injectors at the time of doing this particular shoot. Most of our struggle in this video with the hoses at the back of the engine bay was due to the intake manifold being in the way in one way or another on nearly every hose, with the exception of the two radiator hoses. The upper radiator hose removal was included in part 1, and the lower radiator hose removal is included here. We also reinstall the hose leading from the bottom of the coolant expansion tank to the plastic hose under the manifold on the right side of the engine.

One of the other issues, among many, that we were having with the car was that we weren’t getting any heat in the cabin all winter. So we took this opportunity to try and “flush” out the heater core by attaching a couple hoses to it (the old ones), and then pouring distilled water through it. This seems like a useless thing to do, especially because as you can see in the video it looks like nothing really happens but it must have done something as the heat began to work while running the engine (in Part 4) testing out the new hoses. If it didn’t help, the replacement of the heater core is no small job, as it requires the removal of the dashboard to service or replace it.

One final thing, the lower rad hose has a temperature sensor on it. Don’t forget to purchase a new O-ring and move it over to the new hose before you install it. Alternately, if your temperature sensor is bad, this is a good time to replace it (the sensor on this car was still functional).

Anyway, enjoy the video!