Should you flush BMW cooling system?

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BMW fluids are supposedly "lifetime" fluids. Minus engine oil of course.
 
Originally Posted By: mattd
BMW fluids are supposedly "lifetime" fluids. Minus engine oil of course.


And brake fluid. BMW is the only manufacturer I know of that specifies brake fluid flushes every 2 years.
 
Originally Posted By: exranger06
Originally Posted By: mattd
BMW fluids are supposedly "lifetime" fluids. Minus engine oil of course.


And brake fluid. BMW is the only manufacturer I know of that specifies brake fluid flushes every 2 years.

Mercedes recommends DOT-4 and 2 years brake flush too.
 
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Originally Posted By: mattd
BMW fluids are supposedly "lifetime" fluids. Minus engine oil of course.


I'm pretty sure that coolant is on either the 3 or 4 year interval schedule. I suppose it may depend on which BMW you have and when exactly it was built.

The OE blue BMW G-48 isn't considered "lifetime" anywhere I've ever seen. On my E39 the driveline fluids are stated as "lifetime" (as in catch, store, and replace the old fluid if you open the system for service), PS is overlooked, coolant is 4 years, brake fluid is 2 years, IIRC.
 
Changed mine when the expansion tank cracked. Changed the upper hose, thermostat, temp sensor rad cap and belts too. 103,000 miles at that point.
 
Yes, and brake fluid. I should have known that because i changed mine in my old BMW a couple times.

IIRC, the coolant i believe is considered lifetime also.
 
Various brands have put "lifetime" on their fluids from time to time. Most have recalled that statement a few years later. But if you've read the air filter thread with the link to the Ford filter development, their "lifetime" as I remember was a design for 150,000 miles.

It depends on what you consider a lifetime.

I think everyone recommends brake fluid at 2 years or so, coolants between 4 and 5.

When CVT's started becoming popular, many said the fluid was "lifetime". That has since changed, but no consensus on when to change other than the dealer di-electric tests.
 
Originally Posted By: mattd
BMW fluids are supposedly "lifetime" fluids. Minus engine oil of course.
Lifetime of the lease.
 
What makes the coolant and cooling system materials different in BMW product that allows them to declare that it is a lifetime coolant? My guess is there is nothing different.

I find it very presumptuous of BMW to use their name and create a mystique of how "special" their cars are in ordinary ways.
 
Originally Posted By: Kestas
What makes the coolant and cooling system materials different in BMW product that allows them to declare that it is a lifetime coolant? My guess is there is nothing different.

Interesting question.

I think it's just that they expect the coolant to last until the cooling system needs some kind of repair anyway, and "lifetime" is just marketing-speak for "you'll end up replacing it incidentally before it'll be due for replacement anyway."

I do know their coolant spec is different from most; I don't think it's a stretch to imagine that that is a factor.
 
I'm digging this thread up from the grave but thought I'd share a great BMW coolant flush experience:

First proof "lifetime" fluids are a joke:
z4coolant.jpg




The newer BMWs have electric water pumps and a cool "vent" mode. You turn the ignition to on (but don't start the engine) and press the accelerator down for 10 seconds. The electric water pump will begin to cycle off and on for short intervals for the next few minutes. You can use this time to top off fluid as bubbles work their way out the radiator and hoses, AND you can use it as a way to "flush" clean water throughout the system. Drain and refill a couple times with distilled water, then make your last refill OEM BMW 50/50 mix.

Here's a DIY I wrote up. I'm really pleased with how easy BMW made it!

http://www.zpost.com/forums/showthread.php?p=8903381#post8903381
 
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Very nice feature!

We routinely run fleet vehicles until they require a component replacement, thus I guess we run 'lifetime' coolant also.

The fact is if you aren't running it hard and a lot of miles you're going to have to change it just like every other fluid if you want to keep the vehicle long term.
 
Originally Posted By: rainman49
Hey Santov, will your DIY work on a 2004 530i? Nice write-up BTW!


I looked in TIS and the 04 530 seems to have a N52 engine. That means you have an electric water pump and the process should be the same. If you really want PM me you VIN number and I can confirm in TIS what you have. The TIS has both Euro and US data, there's a million combos as to what's what.
 
Actually, it has the M54 engine, normally aspirated. The N52 appeared first in the 2006 model.
 
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Originally Posted By: rainman49
Actually, it has the M54 engine, normally aspirated. The N52 appeared first in the 2006 model.


According to TIS you have drain the block and resevior (it says IF equiped with resevior drain). I'd stay away from that block drain. Those aluminum screws are one time use, and I'm paranoid about how soft the older aluminum can become. I rather "flush" with fresh water to circulate what's in the block.

So sounds like you're just going to do X number of drain and refills, which will take longer since you have to wait for things to cool down between the flush cycles.

According to TIS the vent proceedure is:
Quote:

Pour coolant into coolant expansion tank up to the MAX mark.
Start engine and run at idle speed for one minute (cap open). Then adjust coolant level to MAX
Close cap and run engine up to operating temperatire until main thermostat opens. Check cooling circuit and drain plug for leaks.
 
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