Why not just use BMW coolant? I've been using it the whole time I've had my car.
It's almost impossible to not notice if a rad hose blows anyway. Plus, BMW blue is odorless, so every time you turn on your heater you won't smell the stench of Prestone.
I'm not in anyway saying Prestone is a bad product, I'm saying, why not use the coolant that was actually designed for a BMW, the car you spend hundreds on and, eventually start to love?
Just a thought.
That's a good point Costa. This is how I look at it.
I agree that it is impossible not to notice when a hose ruptures, but if this happens while driving, you will not be alerted to the situation except by an overheated engine. Engine overheats need not destroy the car but they are to be avoided wherever possible for obvious reasons. With a coolant that has a strong odour the situation is different. A burst hose sprays coolant in the engine everywhere. Air that enters the cabin gets sucked in through the engine in some way. So, the strong smell of the coolant that is now spewing everywhere, also gets carried into the cabin. You will instantly notice this and then begin taking action to stop the car and check. This usually does happen before the engine begins to overheat....you need to lose a fair bit of coolant before overheating takes place, although of course this can happen in 5 minutes as well depending on how bad the rupture is.
Secondly, some burst hoses are not severe. You might not notice it in a casual inspection. However, when left unfixed, a small rupture can suddenly turn into a big one and become a showstopper. With a strongly smelling coolant, you will smell the leak even if it is a small one, and then begin to check everything more thoroughly. It is a great warning device.
The reason why BMW does not have a strong smell in their coolants is because they do not design the coolants for E34s, but for their latest cars, where the probability of hoses rupturing is rather low because the cars are not as old as ours, and also because they now have all kinds of warning systems to alert the driver to pressure drops in the cooling system.
Then we come to the question of coolant itself. Is cheap coolant worse than OEM coolant ? Well, it is fairly clear that nothing can go wrong with OEM coolant. That being said, the complex elements of coolant chemistry are in the "bouncing the rubble" category of life for our car. Any modern coolant being sold in the market will do the job as well as any other, and certainly brand name coolants would have no issues. Any exceptional coolant will probably not give you any benefits that are worth having or can be felt, practically speaking. I wouldn't trade my normal coolant with a strong smell and bright colours for an exceptional odourless coolant. That smell and bright colours sir is important, in my experience, when you're driving an old car and especially when you're the person looking after it primarily.
You should not be smelling prestone in your cabin if everything is fine. I do not smell my cheap $3.50 coolant concentrate in my cabin, and I've had to replace practically everything related to the hoses etc in my car. So, if you are smelling any kind of coolant in your cabin, and if you have properly washed off any spilled coolant after you topped up your radiator, I would say that you need to look for any small leaks somewhere, or perhaps tighten up some hose clamps or something. Please open your hood in a windless area, and begin sniffing. Do you smell prestone? If you do, you really should find out why. In any case, check to see all hose fittings are tight and inspect hoses as best as you can. Hoses that are hard are prone to cracks (major or minor) so those need to be checked more carefully and replaced if a suitable opportunity arises naturally. You rad cap and bleed screw ought to be new - since they cost less than $15 in total.
cheers,
Roberto