Cooling system

[bme61679]

I need to replace the belts and pulleys on the M which I hope to do this weekend. While I was DIYing I've considered replacing the water pump, thermostat/housing and changing the coolant. The car is a '98, has about 70k on it. A previous owner flushed the system a few years back so I think its time for some new fluids. I have a bently manual and the DIY’s from www.logun.org. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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I'm getting conflicting info on when water pumps went to metal impellers and what all should be replaced in association.<o:p></o:p>
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To me this falls under preventative maintenance but I also have the mindset of if it ain't broke don’t fix it. Generally speaking everything looks ok: no antifreeze in the oil, rad. cap is clean, rad. neck is in good shape, hoses look good, temp needle at 12, etc.<o:p></o:p>
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Any reason I shouldn’t change the water pump, do metal ones still need to be replaced periodically?<o:p></o:p>
Any reason I shouldn’t change the thermostat/housing? <o:p></o:p>
Is a new radiator, expansion tank, hoses needed? <o:p></o:p>
Is it necessary to flush the entire system (via engine plug) or just drain the radiator? <o:p></o:p>
Anything else I should be doing/checking while I'm in there?<o:p></o:p>

[northeast m3]

I need to replace the belts and pulleys on the M which I hope to do this weekend. While I was DIYing I've considered replacing the water pump, thermostat/housing and changing the coolant. The car is a '98, has about 70k on it. A previous owner flushed the system a few years back so I think its time for some new fluids. I have a bently manual and the DIY’s from www.logun.org (http://www.logun.org). <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
<o:p></o:p>
I'm getting conflicting info on when water pumps went to metal impellers and what all should be replaced in association.<o:p></o:p>
<o:p></o:p>
To me this falls under preventative maintenance but I also have the mindset of if it ain't broke don’t fix it. Generally speaking everything looks ok: no antifreeze in the oil, rad. cap is clean, rad. neck is in good shape, hoses look good, temp needle at 12, etc.<o:p></o:p>
<o:p></o:p>
Any reason I shouldn’t change the water pump, do metal ones still need to be replaced periodically?<o:p></o:p>
Any reason I shouldn’t change the thermostat/housing? <o:p></o:p>
Is a new radiator, expansion tank, hoses needed? <o:p></o:p>
Is it necessary to flush the entire system (via engine plug) or just drain the radiator? <o:p></o:p>
Anything else I should be doing/checking while I'm in there?<o:p></o:p>

i have a 95' & i was just going to post basicly the same ?'s

[Blink21Me]

Why wai for something to break before replacing them? I would replace what might need to replace and not worry abot them until another 70k... As for the waterpump, I haven't heard of something else better than the one with metal impeller...

[Oogie_M]

The radiator neck and plastic thermostat housing are prone to break eventually. I've known M3's with 50k that needed new ones and 100K that are still on the original ones. It's hard to tell when exactly it will fail.

If you are just replacing the thermostat and radiator assembly, you can probably get away with just draining and refilling the cooling system. Make sure you follow the bleeding procedure in the Bentley manual so that there is no air in the system.

[bimmer od]

How strange. I was coming here to post the same thing.
However, my plan is a little different.
The car has 110,000 km and I what to change anything that has a chance of going before 200,000 km (Within reason)
Should the rad be on the list?
Thanks
Rod

[IronButt II]

Well... water pumps do fail eventually... plastic impeller or not. I thought the plastic impeller issue was only on the M50 engine... (early 95's), but I may be mistaken.

That said... the radiators in these things are typically only good for about 75-80k... before the plastic necks get brittle. So you might want to think about replacing it now. The old "if it ain't broke, don't fix it" theory works fine... until something breaks at the worst possible time.

Sooooo... if you're replacing the rad, (and all the work that goes along with that) it starts making sense to replace some of those other things while you're in there. And at that point, you could at least pull the water pump and see what you've got.

Other things to check/replace would be the expansion tank/level sensor, hoses, belts, thermostat and housing (replace plastic one with aluminum).

As for the coolant, you really should drain the block as well for a complete flush. It's messy, and a PITA... but you'll live. Use BMW coolant at $20 per gallon... expensive, but worth it. Also make sure you follow the procedure to the letter when you're bleeding the system.

Good luck!

[Bill]

At this price you should think of replacing the cooling system.

http://forums.bimmerforums.com/forum/showthread.php?t=626294

[M3BimmerBilly]

You can also use SAAB and Volvo coolant....i think they sell them for 1/2 of the cost vs. BMW over the counter coolant. They're all G48 formula made by Ashland Chemical (valvoline)

Alternatively, Zerex G-05 (valvoline) is cheaper than all of them and found at Pep boys. This is what I use. Its slightly different in formulation, but wheather or not it actaully makes a difference is debatable. Im sticking with g-05 in my car.

[M3BimmerBilly]

At this price you should think of replacing the cooling system.

http://forums.bimmerforums.com/forum/showthread.php?t=626294

easy and a great value :buttrock

[ChosenGSR]

Are pulleys really something you should be replacing? It doesn't seems like a common failure item.

[bme61679]

http://forums.bimmerforums.com/forum...d.php?t=626294 (http://forums.bimmerforums.com/forum...d.php?t=626294)<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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That is a pretty good price, wish I would have known about it yesterday. <o:p></o:p>
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As for the pulleys, they were fairly cheap and I'm getting a little noise out of them at idle so I figured may as well change them while I had everything off. From what I could find the spring "tensioners" usually last while the bearings in the pulleys typically wear out more quickly.<o:p></o:p>

[ph325is]

FYI, the stewart water pump has a lifetime warranty and it is a better pump. BMW water pumps have been fickle over the years with all the changes why risk it? If you have ever had the water pump suddenly fail you know what a pain in butt it is and it risks severe [expensive]engine damage. Stewart seems to have the solution.

[ChosenGSR]

I'm getting a little noise out of them at idle

What does it sound like?

[IronButt II]

Anything from a dull squeel to a groan...

[baltimoreM3]

Go with the stewart water pump - 5 times better than any version OE and better warranty. This will be the last water pump you install in that car.

Don't forget Red Line's wetter water when adding new coolant

[bme61679]

Dull consistent squeal could describe it. Do you think its something else? <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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Basically notice it when the car is running at idle, cold or hot, A/C on or off. No idea if its there while driving, the Rogue exhaust is the only music/sound that I can hear. From my searching I've narrowed it down to the three pulley’s, I could be wrong.<o:p></o:p>

[northeast m3]

You can also use SAAB and Volvo coolant....i think they sell them for 1/2 of the cost vs. BMW over the counter coolant. They're all G48 formula made by Ashland Chemical (valvoline)

Alternatively, Zerex G-05 (valvoline) is cheaper than all of them and found at Pep boys. This is what I use. Its slightly different in formulation, but wheather or not it actaully makes a difference is debatable. Im sticking with g-05 in my car.

what the major difference between coolant that are in this list then stuff you can get off the shelf at autozone or other parts stores. i always thought coolant was coolant, can you guys please school me on this.

[M3BimmerBilly]

what the major difference between coolant that are in this list then stuff you can get off the shelf at autozone or other parts stores. i always thought coolant was coolant, can you guys please school me on this.

google G48 or G05 and youll get a number of technical papers and post from other sites talking about these formulations. You probably shouldnt put the yellow bottle prestone or orange stuff in your bmw, but people do all the time.

[northeast m3]

google G48 or G05 and youll get a number of technical papers and post from other sites talking about these formulations. You probably shouldnt put the yellow bottle prestone or orange stuff in your bmw, but people do all the time.

thanks! man..., i am still waiting for my service manual to show up. so it kills me when i have to ask stupid ?'s but for now thats the only way for me to find out.