Thread: E39 Faq....
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Unread 09-17-2009, 12:47 AM   #59

Name: Palle
Title: United Newb
Status: Offline
Join Date: Sep 2009
Location: Denmark
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Your Ride: 97 528iA, 90 325iT
Originally Posted by Dan View Post
You say your radiator blew up on you? you notice that "CHECK COOLANT LEVEL" on the OBC now? does your 5 look like it took a leak over night in the garage and didn't wipe up? that would be the uber weak cooling system bmw's seems to have not yet master (on top of the electrical).

what to do you say? well, if you notice a leak, take care of it quick! if you just had it done and it still leaks, check the gaskets unless you have a Geba water pump. Yes, Geba will not only look tougher but will leak on you in a few thousand miles (ask me how i know). the system doesn't leak and shouldn't.

if your radiator blew up, don't go cheap. it's a BMW, drop the extra coin for the expansion tank (that's in line to let you down) and the water pump as well as the thermostat. get them all at once. where to get? that's up to you but definitely run down to the dealer and get the water pump gasket. i used one in the box (could have just been because it's made by Geba) and it leaked from the get-go. pretty sweet huh?

let's start with the radiator. you can go with a Behr which is OE. nothing really wrong with it except it's made of plastic and it'll let you down agian... guaranteed. but the price of it isn't so bad so spring one if you like. it comes with ridges in the neck to give it an extra "grip" so the pipe doesn't just slide off.
you can also spring for a Nissen (not Nissan and not the brand that makes noodles) radiator. Some say they are made better but it's still plastic. the radiator neck is smooth then ribbed so some say in certain conditions, the upper radiator hose *might* slip off. who knows, it could just be crappy workmanship or the truth. either way, it's something to think about. the longevity of this "aftermarket" radiator is said to be above OE but some have doubts.
if you are in true baller status and really want to make sure the radiator is a thing of the past, you can fork over a nice coin for this:

it's a lot more then the cost of a Behr or Nissen but it'll never ever let you down EVER again.

so now you'll need an expansion tank. it's that extra canteen looking thing humped on the radiator. yes, it too is made of plastic and it too will fail on you. There's OE's which will work fine since you are going to replace the radiator with the expansion tank all at once so might as well fork over the cash for it; don't get cheap on this, your motor is dependent on this like you are with your liver; sure you can live with 1/2 a liver but do you really want to?
again, if you are a baller and really have no patience for things failing over and over again, get a Lexus... Just kidding! if you are tired of servicing your cooling system, here's the package made just for you:

yes, the price says it all but you know what? you're NEVER EVER going to post: "i got stuck because of my radiator".

so we covered the radiator and the expansion tank. 2 very critical components and like death and taxes, will definitely fail on you. you should also look into the water pump. the OE pressed aluminum foil impeller is good to be used as a home made spinner firework. you do have some choices but i will say this: NOT GEBA. E36 guys have had hell with them and so have I. it was too late for me though. i bought it and half way thru the install i read about a post noting the failure rates of Geba water pump. There's other out there that you can get is very good news. Graf is the OE replacement and it serves it's purpose, pump water around the block. it's OE so you're still going to get the pressed aluminum foil quality impeller but think of it this way: it was working fine so why re-invent the wheel. if it worked before, it should work again. nothing wrong to think like that and many have gone this route. there are other options as far as water pumps since the price could make the difference. Laso is another water pump out there. built of the same quality, it serves it purpose and serves it well. neither of them are price too far from each other so it's a matter of personal preference. A new contender that i never heard of but it's been raved by the fanatical Volvo owners (those who own a true Volvo, before Ford took over and as much as i hate to stereotype, they are truly into getting quality parts because anything less then perfect will freak them out, maybe that's why they don't own a BMW) is the brand: Hepu. it could be found here:
Hepu water pump

it's a bit more (like $20... just skip out on your kid's allowance for a week or something) but i'm going to try it out and report back.

thermostat is a thermostat is a thermostat unless you go for the cooler popping ones but that's a special case and i'm not going to cover it. this part isn't expensive and they are usually priced all the same (give or take) but you REALLY should replace it. last thing you want to do is fuck youself by not replacing this part and having it go bad or worse.. leak and short your ECU.

if you need cooling system parts, contact Bill (
Good information in this thread and this forum: I'm new here and live in Copenhagen.
I have not had specific problems with Nissen radiators. The full Alloy version produced by Zionsville makes You believe that it will never ever let You down... However a radiator is clogging up inside like Your Coffee-maker, and after 6-8 years it will not cool more than half the amount it did, when new, regardless full alloy frame or not. You can delay the problem by rinsing it like You do with Your coffeemaker every once in a while.
And here is how You can preserve the Behr or Nissen radiator: It is probably the pressure build-up at the entrance caused by decreased flow which causes the plastic frame to crack.
BMW Service instructions tells You to change the coolant every 2 years. Use a high quality coolant. If You at the same time flush Your radiator with a cleaner then it will last much longer, even the Behr or the Nissen - which I prefer when buying a new.
If You stick to the same old radiator and never changes the coolant, then usually it will clogg-up, and then during summer, driving slowly in dense traffic, the cooling system can't do the job and the engine overheat. Even the waterpump is probably overloaded or stressed too much when the radiator flow is hampered. So using a radiator, which will last and last despite the clogging, will cause faults elsewhere, eventually causing the engine to overheat = Blown cylinderheadgasket or worse...
Remember that app 40% af all breakdowns are caused from lack of service to the cooling system...
Re cooling hoses: change them when they grow in diameter - often close to the hoseclamps. And use high quality hoseclamps always...Dont use grease if the hose is difficult to mount, rubber is lubricated with a little water, and check again after ventilating the cooling system.
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