drain the coolent, ten remove the 4 10mm bolts, swap it with the new one. thats about it really

 

I used the Bimmerfest search function for E39 cooling system.

Found this:
http://www.bmwtips.com/tipsntricks/Thermostat/tstat.html

Since you have to remove the fan, might as well do the water pump, expansion tank, radiator, and related hoses. I am sure they are all about due.

Good luck.

 

o man mybad, i thought u had a 540i. yah misterlance's advice would be more helpful then mine. sorry

 

This is my write-up



Go through that carefully, written for 98 528i. So for your 2000 528i, the only difference is the thermostat housing which itself contains the thermostat (electrically controlled).
Otherwise straightforward:

http://bimmerboard.com/forums/posts/199986/

By the time you need a thermostat (I assume you have at least 80-100K), then time to do the cooling system overhaul (see the write-up), other parts will soon follow:
-Radiator
-Belts
-Tensioners
-Fan Clutch
-Fan Blades etc and etc.

Do the complete overhaul now and you will save time later to do bits and pieces.
Total cost for parts about $550. Labor was mine

Good Luck!

HTH
cn90
98 528i

 

Not to jump the thread-but whats with the electriaclly controled thermostat? is the part electrical , are there little doors in there operated like a tstat.
Poolman

 

+ 1. I wanted to replace my t-stat when I did my vanos but I found out my t-stat was built into the housing and I bought the wrong one. Damn split year E39.

 

I agree with cn90! While you have the fan off, overhaul the whole system. You will be thankful you did. E39 radiators are notorious for going bad around 60K miles.

Here is a part list that I made when planning my overhaul (purchased from https://www.autohausaz.com/index.html

Part Number	Brand / Description	Description	Price	Qty	Total
17111436381	Behr	Expansion Tank/Coolant Reservoir	$67.54	$67.54
11531438632	Metzeler	Expansion Tank/Coolant Reservoir Hose	$23.98	$23.98
11531438633	BMW (OE)	Expansion Tank/Coolant Reservoir Hose; Expansion Tank to Additional Water Pump	$22.98	$22.98
17111712963	BMW (OE)	Fan Shroud Rivet/Fastener; Plastic Expanding Rivet For 8mm Hole, 15mm Diameter Face	$0.23	$0.46
82141467704	BMW (OE)	Miscellaneous Fluids/Treatments; BMW Antifreeze; 1 Gallon	$23.57	$47.14
17111436060	Nissens	Radiator	$129.95	$129.95
11531705224	BMW (OE)	Radiator Hose; Lower with Temperature Sensor Fitting	$22.66	$22.66
99000003352	BMW (OE)	Radiator Hose; Radiator Vent Hose Fitting Nipple	$1.60	$1.60
11531705223	BMW (OE)	Radiator Hose; Upper with Bleeder Screw Fitting	$23.50	$23.50
17111427156	Elaplast	Radiator Hose; Vent Hose from Radiator to Expansion Tank	$5.58	$5.58
5PK0863	Conti-Contitech	Serpentine Belt/Ribbed Drive Belt; A/C Compressor	$9.59	$9.59
6PK1538	Conti-Contitech	Serpentine Belt/Ribbed Drive Belt; Alternator/Power Steering/Water Pump	$16.58	$16.58
11530139877	Wahler	Thermostat; Thermostat Kit with Housing and Seal	$53.74	$53.74
					$425.30
EXTRAS
17111712788	Vaico	Coolant Bleeder Screw; At Expansion Tank/Radiator - Reuse old one if in good condition	$3.42	$3.42
17111723580	BMW (OE)	Coolant Bleeder Screw; Mounting Clip for Expansion Tank - Reuse old one if in good condition	$1.78	$1.78
17111742231	Reutter/CRP-Continental	Radiator Cap/Expansion Tank Cap; 2.0 Bar - Reuse old one if in good condition	$8.80	$8.80
17111737706	BMW (OE)	Radiator Mount; Lower Left Radiator Mounting Bracket - Reuse old one if in good condition	$7.75	$7.75
17111737707	BMW (OE)	Radiator Mount; Lower Right Radiator Mounting Bracket - Reuse old one if in good condition	$7.95	$7.95
17112246750	BMW (OE)	Radiator Mount; Rubber Lower Mount- Reuse old one if in good condition	$12.13	$24.26
11537509357	VictorReinz	Thermostat Gasket/Seal; Thermostat Housing to Block - New pump should have gasket	$4.20	$4.20

*******> ********>

 

check if you need idel pully, mine changed at the same time as I found it have play even it didn't make noise

 

I just ordered a new tstat, housing and o-ring. Will I need to apply some sort of sealant to the housing?

It isn't really mentioned in the e39 cooling overhaul.

 

Cooling system overhaul DIYs:
- Pictorial look at typical E39 cooling system failure modes (1) (2) (3)
- Complete cooling system overhaul recommended parts list (1)
- Coolant, for engine, automatic transmission, power steering, and AC evaporator cooling (1)
- Bleeding the cooling system (1) (2) (3)
- How to refill M52/M54 coolant DIY by cn90 (1)
- Cooling system DIY (cn90 1997-1998 M54TU) (cn90 V8) (aioros '99-03 M54) (Ågent99 '01 530i) (pelican 3-series)
- E39 Fan shroud removal DIY (Besian) (M54)
- Removal instructions for the alternator & drive belt system of a 2002 525i
- Removal instructions for the fan shroud of a 2002 525i
- Tools necessary for a cooling system overhaul
- Cooling system overhaul tips (fan clutch nut removal tools) (cn90 fan clutch nut replacement trick) (bb hose removal trick) (o-ring replacement parts)
- Cooling system overhaul mishaps (broken radiator nipple) (crooked fan clutch nut) (broken bleeder screw) (thermostat loom misplaced) (broken expansion tank nipple & cn90 repair) (expansion tank fell apart inside)
- Expansion tank floating mechanical coolant level sensor height (1) (2)
- High instrument cluster check of the cooling system temperature KTMP (1)
- Cooling system date stickers & radiator date codes & markings (1) (2)
- What brand of waterpump to buy (1)
- Fan clutch failure modes (1)
- Fixing a head gasket coolant leak (1) (2)
- What is the temperature of the coolant & when the thermostat opens under normal conditions (1)
- Modifying the cooling system (pressure cap) (zero psi fluids) - Zionsville (BlackBMWs) (William) (ohmess)
- Understanding the AUC automatic air recirculation (aka stink) sensor (1)
- Behr radiator and Behr expansion (aka surge) tank autopsy (1) (2) & request for another autopsy (1)
- Debugging overheating problems not related to low fluid levels (1)
- How to install and remove an Oetiker clamp (1)

 

Where do you guys recommend to buy the thermostat from? Can I buy it from Autozone? Or should I get genuine BMW parts? From where?

 

Didn't the 525 come out in 2001?