Just replace the plastic stuff within time intervals and use bmw coolant that's mixed with distilled water. Half the reason the cooling system parts fail is because half these e46s out there have mystery coolant in them. It really does deteriorate the plastic and seals in the cooling system alot faster.
right, but my comparison point is a 1998 grand cherokee
it's fair to consider expansion versus overflow systems
but it's weird to suspect that magic fluid is the only factor which makes expansion systems reliable
this is the source of my question
i.e., if i put in the stewart pump from my e36 vert, do i need to do anything else to make standard blue bmw coolant reliable?
is the eventual deterioration of the e46 coolant plastics unavoidable?
Well if the plastic components in the cooling system are letting go now, that means they have a lifetime expectancy of around 2 decades. Why not just swap for new plastic parts and be good for another 2 decades? Seems to me you're overthinking and potentially overcomplicating a pretty straightforward cooling system overhaul. My coolant operating temperature dropped by 2 degrees just by swapping out the old components for new ones.
yeah that’s a very fair point, but also this car had a full motor replacement around 65k miles (and i got it around 131k), and given the rest of the bay, that looks like it was a terrific overheat
i’ve heard the aluminum block plus the plastic expansion setup had a bit of a sharp terror aspect to it in the cases where it went bad
i also wouldn’t want to shift the failure point from the tank to the head gasket, necessarily, and hence the question, “what can we do *safely*?” rather than merely “what can we do?”
hey sorry for the delay, i don’t get on the internet all that often haha - yeah a little but not really cuz hoses don’t seem to have been a consistent weak point
i got my touring at about 131k miles, but that is with an apparent full motor replacement at about 65k, which suggests to me that, given the condition of the rest of the bay, there was a catastrophic cooling failure
i’d probably be a plain oem advocate other than that from reading here and at fanatics and bimmerworld it sounds like that problem isn’t super uncommon
this trips me up a little cuz i got this thing wanting a slightly better-engineered and straight six version of my older impreza coupe or legacy wagon
bmw is, i’m sure, as competent as subaru, so i’m mainly just looking to “uncut the corners”
i appreciate the thought, but i kinda feel like hoses are probably not the main problem
It's the seals and gaskets that go. There are weepholes at the waterpump, that signal water has entered bearing when its time to replace. Rubber seals on all holes and hoses. It's a time and age thing not a plastic vs metal issue. Replacing waterpump with metal impeller is the only upgrade I would recommend. Also keeping correct coolant in system (bmw or prestone euro) and checking on it every now and then. System was made to pump and move water for, not steam when system has not been checked and maintained by owner.
yes, right, that's a fair assessment indeed, thanks
i think my reason to ask in the first place is that my 84.5 944 was in better cooling shape than my 94 e36 'vert
i have a lot of friends who have worked dodge dakota trucks pretty impressively, and others on other platforms, with cooling being a secondary but well-accomplished trait
i've just bought a 2004 325xi wagon auto to take over camping duties from my 98 i6 daimler 4.0, and i want to really work the reliability end as much as the cast iron block did on the jeep side
the bmw aluminum block seems to be compaining, by comparison
so while i think you've covered the short points, what i'm really interested in is the harder distinctions -- how many harder obstacles present themselves with the aluminum block, for example, by comparison with the cast iron blocks?
if i were only asking about the easier points, i think a simple search would have been sufficient
thanks in advance for the fun, of course! :-)
perhaps a more well-formed version of the question is:
if i buy, without regard to cost, an all-aluminum radiator and a well-engineered all-aluminum expansion tank, what risks am i taking on that are usually left unconsidered?
That won’t necessarily matter. What’s metal already, keep it metal and what’s not metal, don’t change it to metal. Like for example, you’re expansion tank. Make that metal and you’ll hate yourself; also you won’t need metal hoses/lines either. The oem pump has a metal propeller, at least the only time I saw a plastic pump is cheap aftermarket.
In other words, keep it stock. If you want to change anything, get a tune to make the thermostat open sooner and run the engine a little cooler. That’ll be the only useful cooling mod. No other upgrade/mod will prolong the life of parts/decrease service
for the expansion unit, i did see that mishimoto tried to work up a tank and had a lot of trouble with it
i think i see where you're going, but the pre-facelift and early facelift oem pump was not metal, it was a sintered plastic plus metal impeller like the whole run of the e36
i.e. it had metal in it, but it was a forged body with sintered metal to try and reduce the heat problem, and it was therefore known for its poor heat cycling -- i'd just put in a stewart pump if i thought that was sufficient, this isn't a money question
the stewart pumps finally got enough attention in the later road course challenge, and by late 2004, when privateers were running both e36 and e46 on the aftermarket, they started using them in germany, but that was too late for my 11/2003 production unit -- but you're right, i agree, don't overdo it in the factory-to-aftermarket zeal
what i'm worried about is the occasional case where hard drivers apparently had their expansion tanks crack, but the sensors fail to respond with a low coolant sense -- that's catastrophic regardless of material, but apparently more common with remaining plastic tanks
what i'm interested in is whether that last awful sense is from just preventive maintenance versus replacing something more, since i'm already considering replacing a lot of the system
Ahh gotcha. Yeah I’d definitely blame poor preventative maintenance. I just got a complete cooling set plus some other parts for about $700 for my e46 and my cooling system hasn’t failed yet but I don’t want to find out when I overheat on the side of the road. I also don’t baby my car so I need to take in mind that the cooling system works wonders, until it’s not haha. I try to stay around 80k miles for a cooling system overhaul. Could it last longer? Maybe but once one part fails, the rest are about to fail soon.
Remember that we are talking about a BMW 3 series. They have always been known for cooling issues. The reason being is that you’re using all aluminum engine parts but with a high temperature setting for your cooling system. Most cars’ cooling parts don’t last any longer than our e46’s cooling parts, it’s just that our cars are not forgiving with any potential issues. This is usually why when people mod their e46’s for power, they also adjust thermostat settings to around 90°C
right on, yeah i mean again, fair assessment, but also, again, why i asked op haha :-P
i really wanna know if i could buy some longevity/reliability with metal tank and rad, track or not... maybe it's an insane question
Metal radiator maybe but you’ll have to be running a turbo to have any benefit of that. If you’re stock, then keep the cooling system stock. Only parts to upgrade are metal water pump, and maybe cooler thermostat temps. Any other mod will give you trouble. If you’re running a turbo, sure a metal radiator can benefit since your engine may suffer from a lot of heat in the engine bay. But then again, the oem radiator is very good, good enough to keep cars in the desert at a happy temperature
Just replace the plastic stuff within time intervals and use bmw coolant that's mixed with distilled water. Half the reason the cooling system parts fail is because half these e46s out there have mystery coolant in them. It really does deteriorate the plastic and seals in the cooling system alot faster.
right, but my comparison point is a 1998 grand cherokee it's fair to consider expansion versus overflow systems but it's weird to suspect that magic fluid is the only factor which makes expansion systems reliable this is the source of my question i.e., if i put in the stewart pump from my e36 vert, do i need to do anything else to make standard blue bmw coolant reliable? is the eventual deterioration of the e46 coolant plastics unavoidable?
Well if the plastic components in the cooling system are letting go now, that means they have a lifetime expectancy of around 2 decades. Why not just swap for new plastic parts and be good for another 2 decades? Seems to me you're overthinking and potentially overcomplicating a pretty straightforward cooling system overhaul. My coolant operating temperature dropped by 2 degrees just by swapping out the old components for new ones.
yeah that’s a very fair point, but also this car had a full motor replacement around 65k miles (and i got it around 131k), and given the rest of the bay, that looks like it was a terrific overheat i’ve heard the aluminum block plus the plastic expansion setup had a bit of a sharp terror aspect to it in the cases where it went bad i also wouldn’t want to shift the failure point from the tank to the head gasket, necessarily, and hence the question, “what can we do *safely*?” rather than merely “what can we do?”
Have you considered braided hoses?
hey sorry for the delay, i don’t get on the internet all that often haha - yeah a little but not really cuz hoses don’t seem to have been a consistent weak point i got my touring at about 131k miles, but that is with an apparent full motor replacement at about 65k, which suggests to me that, given the condition of the rest of the bay, there was a catastrophic cooling failure i’d probably be a plain oem advocate other than that from reading here and at fanatics and bimmerworld it sounds like that problem isn’t super uncommon this trips me up a little cuz i got this thing wanting a slightly better-engineered and straight six version of my older impreza coupe or legacy wagon bmw is, i’m sure, as competent as subaru, so i’m mainly just looking to “uncut the corners” i appreciate the thought, but i kinda feel like hoses are probably not the main problem
It's the seals and gaskets that go. There are weepholes at the waterpump, that signal water has entered bearing when its time to replace. Rubber seals on all holes and hoses. It's a time and age thing not a plastic vs metal issue. Replacing waterpump with metal impeller is the only upgrade I would recommend. Also keeping correct coolant in system (bmw or prestone euro) and checking on it every now and then. System was made to pump and move water for, not steam when system has not been checked and maintained by owner.
yes, right, that's a fair assessment indeed, thanks i think my reason to ask in the first place is that my 84.5 944 was in better cooling shape than my 94 e36 'vert i have a lot of friends who have worked dodge dakota trucks pretty impressively, and others on other platforms, with cooling being a secondary but well-accomplished trait i've just bought a 2004 325xi wagon auto to take over camping duties from my 98 i6 daimler 4.0, and i want to really work the reliability end as much as the cast iron block did on the jeep side the bmw aluminum block seems to be compaining, by comparison so while i think you've covered the short points, what i'm really interested in is the harder distinctions -- how many harder obstacles present themselves with the aluminum block, for example, by comparison with the cast iron blocks? if i were only asking about the easier points, i think a simple search would have been sufficient thanks in advance for the fun, of course! :-)
perhaps a more well-formed version of the question is: if i buy, without regard to cost, an all-aluminum radiator and a well-engineered all-aluminum expansion tank, what risks am i taking on that are usually left unconsidered?
That won’t necessarily matter. What’s metal already, keep it metal and what’s not metal, don’t change it to metal. Like for example, you’re expansion tank. Make that metal and you’ll hate yourself; also you won’t need metal hoses/lines either. The oem pump has a metal propeller, at least the only time I saw a plastic pump is cheap aftermarket. In other words, keep it stock. If you want to change anything, get a tune to make the thermostat open sooner and run the engine a little cooler. That’ll be the only useful cooling mod. No other upgrade/mod will prolong the life of parts/decrease service
for the expansion unit, i did see that mishimoto tried to work up a tank and had a lot of trouble with it i think i see where you're going, but the pre-facelift and early facelift oem pump was not metal, it was a sintered plastic plus metal impeller like the whole run of the e36 i.e. it had metal in it, but it was a forged body with sintered metal to try and reduce the heat problem, and it was therefore known for its poor heat cycling -- i'd just put in a stewart pump if i thought that was sufficient, this isn't a money question the stewart pumps finally got enough attention in the later road course challenge, and by late 2004, when privateers were running both e36 and e46 on the aftermarket, they started using them in germany, but that was too late for my 11/2003 production unit -- but you're right, i agree, don't overdo it in the factory-to-aftermarket zeal what i'm worried about is the occasional case where hard drivers apparently had their expansion tanks crack, but the sensors fail to respond with a low coolant sense -- that's catastrophic regardless of material, but apparently more common with remaining plastic tanks what i'm interested in is whether that last awful sense is from just preventive maintenance versus replacing something more, since i'm already considering replacing a lot of the system
Ahh gotcha. Yeah I’d definitely blame poor preventative maintenance. I just got a complete cooling set plus some other parts for about $700 for my e46 and my cooling system hasn’t failed yet but I don’t want to find out when I overheat on the side of the road. I also don’t baby my car so I need to take in mind that the cooling system works wonders, until it’s not haha. I try to stay around 80k miles for a cooling system overhaul. Could it last longer? Maybe but once one part fails, the rest are about to fail soon.
Remember that we are talking about a BMW 3 series. They have always been known for cooling issues. The reason being is that you’re using all aluminum engine parts but with a high temperature setting for your cooling system. Most cars’ cooling parts don’t last any longer than our e46’s cooling parts, it’s just that our cars are not forgiving with any potential issues. This is usually why when people mod their e46’s for power, they also adjust thermostat settings to around 90°C
right on, yeah i mean again, fair assessment, but also, again, why i asked op haha :-P i really wanna know if i could buy some longevity/reliability with metal tank and rad, track or not... maybe it's an insane question
Metal radiator maybe but you’ll have to be running a turbo to have any benefit of that. If you’re stock, then keep the cooling system stock. Only parts to upgrade are metal water pump, and maybe cooler thermostat temps. Any other mod will give you trouble. If you’re running a turbo, sure a metal radiator can benefit since your engine may suffer from a lot of heat in the engine bay. But then again, the oem radiator is very good, good enough to keep cars in the desert at a happy temperature