1995 540i Thermostat Cover

[Clarksonvalley]

The 'ETK' parts file shows a large O-ring between the Thermostat and the Water Pump. I think this is wrong - I think the O-ring goes between the Thermostat Cover and the Thermostat. Anyone have any experience with this?

Just returned from a road trip from St. Louis, MO to Bend, Oregon and back - 4,918 miles including side trips to Yellowstone, Jackson Hole, the Badlands and Devils Tower in a 1995 540i with 234,454 miles on the odometer. Averaged 25.6 MPG and used probably less than one pint of oil traveling on I-80 and I-90 at 80 MPH and 2600 RPM in 6th. I kind of felt like I was driving a time bomb with that many miles, but all went well.

[shogun]

In below link is a pdf, in case you cannot open it as you are not registered there, here is the text, pics in the pdf:
Thermostat and Thermostat Housing -Replacement DIY Guide for BMW M60 V8 Engine
Written by: Actros617 BMW GUIDE - This procedure is documented on 1993 BMW E32 740il

This guide is to help you in replacing the thermostat, a routine maintances item, and the original plastic thermostat housing to a metal billet one. If you still have the plastic Themostat Housing I highly recommend replacing it with the metal. The plastic thermostat housing are notorious of leaking around the its joining area this task is easy and staright foward. Disclaimer: This is to article guide you though, I will not be held responsible for any injury/death or property damages from following this guide. DO IT AT YOUR OWN RISK, YOU’VE BEEN WARNED!!

Let’s get started!!
WARNING: Before you begin please make sure your engine is COLD; you don’t want to scald yourself with boiling hot radiator fluid!!
Caution: Radiator Fluid is TOXIC and is considered a Hazardous Material, please do not dispose of it in your street drainage, follow your state and city Hazmat disposal policy. And you spilled coolant on the floor wash if off ASAP and please keep all
pets and kids away from your work area!!

1. Remove the Engine Acoustic Cover
2. Remove the upper air intake box, air intake boot from the throttle body and MAF sensor.
3. Unbolt the two bolts and remove the lower part of the air intake box so you’ll have space to access the Thermostat housing.
4. Place a catch pan and drain the radiator fluid then remove the radiator hose from the thermostat housing and move it away. Check the hoses for any cracks, replace them if needed.
5. Remove this vacuum line from the throttle body for better access to the thermostat housing left upper and lower bolt, check the hose, replace it if needed.
6. Location of the bolts that is holding the thermostat housing in, two on the top and two on the bottom. Remove them and the housing should come right off, if not use a block of wood and give it a few gentle taps and it should fall off. Be sure you have a catch pan under the car when you remove the thermostat! There’s at least 1 gallon of coolant in the engine block that will come rushing out so be prepared!
6b.Comparison between the plastic (black) and metal thermostat housing.
7. Slip on the new rubber O-ring (left pic) on to your new thermostat, install it on to the water pump housing (middle pic), and be sure you line up the thermostat relief valve into its square notch on the thermostat housing!!
8. Install the thermostat housing and bolt it down.
9. ABC.
A) Reconnect the lower radiator hose on to the thermostat housing, vacuum line to throttle intake and reinstall the air intake system.
B) Fill the system up with coolant (BMW Orange Coolant or Zerex g-05 recommended do not use GM dex-cool!)
C) Next start your car up and turn on your heater to MAX, and check your level.
Note: this cooling system is a self-bleeding system, no bleed procedure required. Be sure you check your temperature and your coolant level for the next few days, top off if needed

And that is it you’re done!! Please be sure to dispose of your old coolant properly and wash of any coolant on your drive way A.S.A.P. I hope this guide has helped you!

http://www.bimmerforums.com/forum/showthread.php?2102326-HowTo-gt-gt-M60-Thermostat-Housing-Replacement-DIY

I remember also for the M70 engine the ETK drawing is apparently wrong, here is the procedure for the M70, there you can also see the O-ring position
http://bmwe32.masscom.net/sean750/waterpump/waterpump.htm

Here also very good pics where the o-ring goes on the M62 http://www.bimmerforums.com/forum/showthread.php?1461973-HowTo-gt-M62-thermostat-mod-(lower-engine-temp)

[Clarksonvalley]

How do I access the 'http://www.bimmerforums.com/forum/sh...eplacement-DIY'? Being logged in does not seem to give me access. Anyway, I've got the O-ring in my way (not the ETK way) and it does not leak.

[shogun]

Here again the link http://www.bimmerforums.com/forum/showthread.php?2102326-HowTo-gt-gt-M60-Thermostat-Housing-Replacement-DIY
In case you still have probs with tghe direct link, go there to BMW E32 Common Problems and DIY Fixes and there you find it
http://www.bimmerforums.com/forum/forumdisplay.php?312-E32-Common-Problems-and-DIY-Fixes

[632 Regal]

The 'ETK' parts file shows a large O-ring between the Thermostat and the Water Pump. I think this is wrong - I think the O-ring goes between the Thermostat Cover and the Thermostat. Anyone have any experience with this?

Yes there is supposed to be an O ring between the thermostat and housing. When you get a new thermostat housing it should be supplied. Also get the aluminum housing as the plastic ones give out, along with the plastic impellers on some replacement pumps.