I hope I am not monopolizing the airwaves here but trying to keep 3 BMWs going with mediocre knowledge is a task, so here I post. I turns out I have a cracked radiator neck so I need a new one. Any suggestions on a good radiator for everyday M3 driving. Looks like Behr and Nissens are the main names with a Langerer and Reich for another $58 approx. What should I be checking besides the therm housing (replace plastic) while in there? Some fellow wrote below the Pelican DIY that you did not need to remove the fan, why would pelican write up the DIY that way if it could be done easier? I suppose a couple extra plastic fastening devices would be in order but what about the fan/temp switch and sensor plug. If I can use the old switch at over $30 I will. I just flushed my system so I plan on saving the old coolant and run it through a coffee filter. As always thank for the help.
The old switch will be just fine. I am assuming you are asking about the coolant level sensor as well. I tend to run those until they fail. You may not need to remove the fan, but if you make a mistake and nail the radiator with a fan blade while installing it, you may regret it. Behr is OE, and I have had no problems with Nissins for the E36, though I have with some other models. Never heard of the others. Not a bad time to do the thermostat, being that lots of the coolant is out of the car, but not really a huge deal if you don't (I would, though, especially if you still have a plastic t-stat housing.) Having new radiator clips is nice if you don't know how to get the old ones off or are afraid you will break them. Also new fan shroud plastic fasteners are good to have. You will need at least one hose clamp as well for the crimped on bleed hose that goes between the top of the radiator and the reservoir. DON'T screw up the routing of that hose. If you do, the fan will catch it and leave you with a coolant leak when you least expect.
I just got a recommendation for a ETD aluminum radiator on Ebay. I wonder how that would stack up. Thank again for your help.
Well, the neck would never rot off. I'd say if it didn't leak when installed that it would probably last another couple decades at least.
I will research it Paul. I think I figured out why the neck went on me. The last guy kind of babied the car and I was nailing an on ramp at about 6,000 rpms in third at 60 mph and it was just the right combo of stresses on the weak point that made it blow. I like the idea of a metal neck since there is so much failure talk, I do not know if it is just within this particular line of cars or manufacturers but I want to fix it right. Reply if you like there is no question I just like to ramble on sometimes.
Actually, it went because they all do. The plastic erodes and gets heat cycling stress which eventually leads to failure, and usually right there. Basically, this will eventually happen to every BMW with a plastic radiator, but the problem is accelerated in the newer cars because the temperatures and pressures they run are higher than the older cars by necessity (emissions.)
I do not have personal experience with all aluminum radiators on street cars but just read an interesting post on Bimmerforums from a gent that strongly recommends against them for a daily driven car. He claims that heat cycling inherent in daily use will always cause the aluminum weld joints to develop cracks and fail. He claims the reason is that the side tanks are heavier gauge aluminum than the core and these parts expand and contract at different rates. He claims to have experienced cracking around the side tank welds with 3 different expensive aftermarket radiators and that the OEM plastic and aluminum construction will last longer in daily drivers. His recommendation is to stick with OEM and just change it religiously at 60K miles. He goes further to say that all aluminum construction is fine for race cars or garage queens that don't see heavy daily use mileage. I suspect his advice has some merit in climates that see a large range of temperature variation during the year. I live in the Northeast and my car certainly sees a large range of temperature swings. I am leaning towards sticking with OEM in my daily driver 525iT with S52 transplant. I do about 25K miles per year minimum and don't want to have to replace an expensive all aluminum radiator for my car in just a few years.
Thanks, I put in a CX racing aluminum for this car that will see maybe 5,000 miles per year tops and is not a daily driver. There are some serious alignment issues with the CX brackets. How do we get the word out to the general public about such issues. I hate to leave bad feedback because for the price it was probably worth a little retrofitting.
I never really thought about that with the aluminum radiators, but it would seem to make sense. Sometimes the cheaper option is more suited to your task, even if it doesn't have the words "racing" or "performance" on it
