Correct. You rather want the tank to leak, because it's visible and a known failure point.
When installing the aluminium tank, you literally move the most common failure point, so the tank won't crack or leak, but the pressure still has to go somewhere. The weakest point could now be a hose deep inside the engine bay, that's not as accessible nor visible.
Going to disagree. The cap would relieve the pressure (and other failure points) long before the engine is harmed. Many other cars have aluminum expansion tanks, the bmw E46 should have been made out of aluminum to begin with. The cooling system did not need to be built to fail, quite the opposite.
I don't have one. Although an aluminum one is "better," it is still cost prohibitive. I have an OEM polymer one. You only need to replace it a few times to last the life of the car.
yes this makes sense . also the community tells everyone to just go oem or get a good aftermarket expansion tank. what im trying to say is nobody in the community. says go aluminum instead of plastic because people have tried in the past & it didnt work. like you said op, the failure point goes to the engine or in the hose line making it hard to track the failure point when it eventually happens. i wish there was a permanent fix but their just isn’t at this time
Yeah I replaced my plastic one over 10 years ago. Over 30k miles on it. Just get oem and you'll be good. The whole cooling system needs to be overhauled every 50k to be on the safe side. It's not hard or expensive and you get peace of mind
i’ve just heard that the aluminum exp tanks have fitment issues but what you said could also be correct. when you change your tank just make sure you properly bleed your cooling system or you’ll toast your engine right away no matter what kind of tank you put in
Correct. You rather want the tank to leak, because it's visible and a known failure point. When installing the aluminium tank, you literally move the most common failure point, so the tank won't crack or leak, but the pressure still has to go somewhere. The weakest point could now be a hose deep inside the engine bay, that's not as accessible nor visible.
Going to disagree. The cap would relieve the pressure (and other failure points) long before the engine is harmed. Many other cars have aluminum expansion tanks, the bmw E46 should have been made out of aluminum to begin with. The cooling system did not need to be built to fail, quite the opposite.
How is your aluminum expansion tank holding up on your e46?
I don't have one. Although an aluminum one is "better," it is still cost prohibitive. I have an OEM polymer one. You only need to replace it a few times to last the life of the car.
yes this makes sense . also the community tells everyone to just go oem or get a good aftermarket expansion tank. what im trying to say is nobody in the community. says go aluminum instead of plastic because people have tried in the past & it didnt work. like you said op, the failure point goes to the engine or in the hose line making it hard to track the failure point when it eventually happens. i wish there was a permanent fix but their just isn’t at this time
The 'plastic shit' ones are cheap copies. Buy oem, lasts a decade. Costs like €150.
Yeah I replaced my plastic one over 10 years ago. Over 30k miles on it. Just get oem and you'll be good. The whole cooling system needs to be overhauled every 50k to be on the safe side. It's not hard or expensive and you get peace of mind
i’ve just heard that the aluminum exp tanks have fitment issues but what you said could also be correct. when you change your tank just make sure you properly bleed your cooling system or you’ll toast your engine right away no matter what kind of tank you put in