85 323i grey market euro - M tech 1 build.

[reelizmpro]

Barry, are you running a later model radiator and expansion tank:

https://www.r3vlimited.com/board/forum/general-forums/members-rides/the-project-forum/9925456-the-aluminum-monster-soon-to-be-iron#post9925887

Yes, I am for the same reasons he mentioned. However, I did have a blown headgasket and it was consuming coolant. It just never boiled out of the cap like it would with the M42 radiator. I just kept adding water every so often. I very much prefer the late model style cooling system for a few reasons but mainly because it's like the E36 style radiator of which there are plenty of aftermarket options and I get to keep the coolant level sender with the late model reservoir. The wiring runs right by it along the drivers side fender. I think it looks cleaner than the early style pill bottle as well.

[Javier h]

Maybe its just me but I am starting to wonder whether these E36 engines are super sensitive to coolant issues and prone to failure for the slightest infraction! Yes, renewing the cooling system on E36s is a given and part of its critical maintenance but I blew my M52 at 200k and I did everything clock work knowing its short comings. Maybe I should have replaced everything at 80k instead of waiting for 100k....temps etc were spot on but I read threads like yours and now Simon's and you start wondering. My leak was just that...external coming from the side block, no mixing with the oil but still...I replaced it along with all those cooling related component/hoses including a new radiator etc.as something caused that gasket to blow.

[reelizmpro]

To be honest, the M50 family is known for HG and/or head problems. I think it's a design flaw exacerbated by cooling issues. I spent a lot of time in my friend's BMW shop in the 90's/early 2000's and seen a lot of blown HG's and cracked heads on 24v engines. Lots of mechanical overrevs as well. It made me reluctant to swap for a long time. When I finally took the plunge, I happen to get an engine with a bad headgasket. Part of me isn't really surprised. I suppose I should be happy it's just a gasket and not a cracked head as well. I remember my E39 528i started overheating on the freeway so I changed the water pump and thermostat and it stilI overheated. What fixed it was a new fan clutch which surprised me since I thought an E39 would have sufficient airflow at highway speed to cool the engine. BTW, my E39 has 286k miles on the original engine. Could it be that E36 drivers tend to hoon their cars while E39 drivers aren't driving their cars as hard?