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raywiebe · Posted: Tue Jun 08, 2010 8:06 pm Post subject: Cooling System Overhaul

I have a 2003 540iA (production date 09/02) w/102k kilometers (63k miles), bought it at 80k (50k miles), live in Canada and it is a daily driver. I baby it and am anal about its maintanence. Last oil change I sent the sample for analysis, came back perfect.
I'm the second owner, pretty sure first owner only did oil changes; in Jan/10 @ 97k, I changed all fluids except coolant, (waiting till summer). Initially I was only going to do hoses, thermostat, water pump w/ the coolant, but after going thru various forums and reading numerous posts and threads about E39 cooling systems and their explosive tendancy I will do the rad w/ expansion tank, fan w/clutch along with the other upgrades.
This week the 'Check Coolant Level' warning flashed at me twice in four days, I checked for leaks, none, coolant level is good. I took the belly pan off and did thorough inspection, all OK. Is this an omen or just bmw gremlins?
I'm about to order all the parts for the complete job and I was wondering if there are any particular name brands that I should order or keep away from? or are there any particular tips or necessary changes to be done while everything is open.
Will it be necessary to change the heater hoses? Are they under the same type of pressure as the rad hoses?
Also, I read about the Zion after market rads (all aluminum w/electric fan), they sound like the bullet proof soulution, are they worth the extra coin?
I would appreciate any insights or recommendations for doing this procedure.
Thanks

edjack · Joined: 04 Feb 2002 Posts: 3887 Location: San Jose, CA

The Zionsville solution is like buying a Rolex. Is it worth it? Only you can decide. The rad is a Thing of Beauty, and will no doubt outlast the car.

Pull up on the red float in the exp tank. If it comes out, the tank is about ready to pop. Mine split open at 88k miles. I then did a cooling system overhaul. There seems to be confusion about Behr versus Nissans rads. I have a Nissans, and it's now at 118k miles. I got a Graf water pump, which seems to be well made, with an iron impeller.

The heater hoses see the same pressure. Carefully examine them. I'm on my originals, perhaps tempting fate.

Be careful removing the water pump, so you don't pull the two pipes out of the rear of the engine. There are two sleeves in the boltholes between the pump and the block, which help to locate the water pump gasket; don't lose them. Also, use the BMW water pump gasket, not the one supplied with the the pump.

Use BMW coolant, mixed with distilled water.

Buy the E39 Bentley Service Manual.
_________________

Ed BMW CCA member since 1987 (Nr. 62319).
'97 540i 6 speed Aspensilber over Aubergine interior.

raywiebe · Posted: Wed Jun 09, 2010 10:57 am Post subject: Cooling System Overhaul

Thanks Ed,
I appreciate your clear straight forward responses.
I checked the red float this AM, still attached. I have the Bentley and the BMW coolant.
Is it necessary or advisable to change the water pump pulley at the same time, is their longevity questionable? I'm not concerned about the cost, just want to make sure I don't over look something.

edjack · Joined: 04 Feb 2002 Posts: 3887 Location: San Jose, CA

As I recall, all the pulleys are plastic, or phenolic. IIRC, I didn't replace any, including the water pump. Your call.

Do examine them carefully for cracks.
_________________

Ed BMW CCA member since 1987 (Nr. 62319).
'97 540i 6 speed Aspensilber over Aubergine interior.

walshja · Joined: 03 Apr 2001 Posts: 1139 Location: guilford, ct, usa

while you have everything out you should think about replacing the belt tensioners and belts, they will eventually go.

my e39 cooling system is def the weak point on my car, causing me much grief recently. my expansion tank blew, then weeks later the water pump started leaking.
_________________
joe

1994 325iC, 195k miles
http://home.comcast.net/~walshja/index.html <--- check it out

raywiebe · Posted: Sun Jun 13, 2010 7:02 am Post subject: Cooling System Overhaul

Thanks walshja,
I replaced all belts in Jan/10, my mechanic and I looked at the tensioners and pulleys carefully and agreed that they were OK for the time being, but I will check again.
I came across a web sight http://eactuning.com that actually has a 'Cooling System Parts List' for a E39 540 (from 09/98), it is very helpful in compliling the required parts.
It also has numerous other 'Parts Lists' for other common DIY procedures for various european cars. Their BMW lists s/b posted on all BMW forums FAQ lists. Very helpful.