What did you do to your E9 today?

[JMinPDX]

Completed a Coolant system flush as I had to replace rusting bypass pipe. (below the intake runners on L-Jet injection)
Old pipe (44 years old):

New pipe (not stainless but coated with Por-15 and high heat paint):

No way to get a good picture of it installed but I also took the opportunity to replace old hoses and new BMW clamps.

The bleeding method I used works really well for me.

There are apparently several ways to purge the cooling system of air. With no particular favorite, Here is another, courtesy of E28 board and J.Rowe at Metric Mechanic:

"There is a sure way to bleed the cooling system on 'big' six engines.
1. After repair is made (before adding coolant) remove bleeder screw and run a small piece of wire down the hole to dislodge any mineral deposits..
2. Replace the screw, but leave valve 'open'.
3. Open heater control valve and add coolant until it begins to escape from the bleeder hole.
4. Now close bleeder screw and replace the expansion tank cap and tighten.
5. Remove the small coolant line that runs from the radiator to the
expansion tank AT THE EXPANSION tank and hold it as high as you can.
6. Now attach another hose the expansion tank in place of the one you've
just removed. BLOW (gently!!) through this hose until coolant emerges from the small elevated radiator hose.
7. Now remove the 'blow' hose and reconnect the small radiator hose to the expansion tank..
8. Now top off the expansion tank to the full mark.
9. Start and warm up engine and check for leaks!!"

Test drove the car, temp gauge stayed below middle and no leaks. Ready for the summer.

 

[Breiti]

Paint the pedal / booster support in dark gray.

Breiti

 

[Ohmess]

Completed a Coolant system flush as I had to replace rusting bypass pipe. (below the intake runners on L-Jet injection)
Old pipe (44 years old):View attachment 181019
New pipe (not stainless but coated with Por-15 and high heat paint):
View attachment 181020
No way to get a good picture of it installed but I also took the opportunity to replace old hoses and new BMW clamps.

The bleeding method I used works really well for me.

There are apparently several ways to purge the cooling system of air. With no particular favorite, Here is another, courtesy of E28 board and J.Rowe at Metric Mechanic:

"There is a sure way to bleed the cooling system on 'big' six engines.
1. After repair is made (before adding coolant) remove bleeder screw and run a small piece of wire down the hole to dislodge any mineral deposits..
2. Replace the screw, but leave valve 'open'.
3. Open heater control valve and add coolant until it begins to escape from the bleeder hole.
4. Now close bleeder screw and replace the expansion tank cap and tighten.
5. Remove the small coolant line that runs from the radiator to the
expansion tank AT THE EXPANSION tank and hold it as high as you can.
6. Now attach another hose the expansion tank in place of the one you've
just removed. BLOW (gently!!) through this hose until coolant emerges from the small elevated radiator hose.
7. Now remove the 'blow' hose and reconnect the small radiator hose to the expansion tank..
8. Now top off the expansion tank to the full mark.
9. Start and warm up engine and check for leaks!!"

Test drove the car, temp gauge stayed below middle and no leaks. Ready for the summer.

I use this procedure, and have some suggestions.

You don't need to hold the expansion tank hose end as high as you can, you merely need to hold it above anywhere in the cooling system that air could be hiding. Best to hold it where you can easily see the end of the hose.

When blowing in the hose attached to the top of the radiator, your objective is to push out all of the air in the system. You know this is done when a very small amount of coolant comes out of that hose end. You want to blow hard enough that a small amount of coolant comes out, but not so hard that the coolant sprays all over the place. So, hold the hose end where you can see it and with the end square to the coolant tank. This helps you determine how hard to blow. Second, wrap a rag around the hose to catch the coolant so it doesn't get on your car or run down your arm.

 

[Stevehose]

Ever since I used @sfdon 's tip on drilling a small hole in the thermostat at 12 o'clock I haven't had to do any bleeding procedures other than a quick bleed screw opening right when the thermostat opens, including the hose in the air technique, which works great otherwise.

 

[JMinPDX]

Ever since I used @sfdon 's tip on drilling a small hole in the thermostat at 12 o'clock I haven't had to do any bleeding procedures other than a quick bleed screw opening right when the thermostat opens, including the hose in the air technique, which works great otherwise.

Yep. Drilling the hole in the t-stat works great. I did that 12 years ago. I still like the expansion tank hose trick for piece of mind.

 

[Stevehose]

Yep. Drilling the hole in the t-stat works great. I did that 12 years ago. I still like the expansion tank hose trick for piece of mind.

Maybe it's coincidence, but also since doing this my temp gauge never wavers from 185, winter or heat of summer with or without a/c on.