Nice and fast way to bleed coolant in M20

[ForcedFirebird]

Do you guys do this with the engine running ? I asume yes, otherwise there will be air on behalf the thermostat not opening ?
And also, what do you do with the remaining coolant in the funnel as the system becomes full ? How do you take the funnel out without spilling ?

Link in post 17 has a stopper in it. I don't use one like that, so coolant goes first, then water, spillage doesn't much matter. The funnel causes the level to be higher than anywhere other point, so both sides of the thermostat get filled. Sometimes you will get a bubble in the heater core that will show after running and heater turned on, but generally not enough to get to the bottom of the expansion tank - easily topped up.

[Xelo]

Do you guys do this with the engine running ? I asume yes, otherwise there will be air on behalf the thermostat not opening ?
And also, what do you do with the remaining coolant in the funnel as the system becomes full ? How do you take the funnel out without spilling ?

[Poorhouse]

Wow old thread!

I have no issues bleeding the m20 systems, and I do a LOT of them, pretty much on a daily basis. It's real simple physics, the coolant needs to be poured in higher than the uppermost hoses/passages (fluids always seek level). So, I use a $1.50 yellow radiator funnel from the local parts store - it fits perfectly in the expansion tank fill hole. Fill it up to the top of the funnel and just wait a minute and all the bubbles will come up through the 8mm hose off the top of the radiator. As the bubbles come up, keep the coolant to the top of the funnel and after a few minutes it will fill completely. Been doing it this way at the shop for the last 11yrs, have never had an air bubble issue - and in fact don't even open the bleeder screw half the time (if I do, it just makes the process only slightly faster).

This X2.

I had a lot of trouble getting mine bled with the ramp method. Doesn't seem like it would ever work as the bleeder isn't the high point, even on ramps.

Found mention of the funnel method. Made sense as you are elevating the bleed point. I bought a fancy Lisle funnel on Amazon for $12. Worked perfectly in just a few minutes.

[digger]

i did another one a couple weeks ago. front was on ramps had zero issues, no holes in t-stat

[ForcedFirebird]

Wow old thread!

I have no issues bleeding the m20 systems, and I do a LOT of them, pretty much on a daily basis. It's real simple physics, the coolant needs to be poured in higher than the uppermost hoses/passages (fluids always seek level). So, I use a $1.50 yellow radiator funnel from the local parts store - it fits perfectly in the expansion tank fill hole. Fill it up to the top of the funnel and just wait a minute and all the bubbles will come up through the 8mm hose off the top of the radiator. As the bubbles come up, keep the coolant to the top of the funnel and after a few minutes it will fill completely. Been doing it this way at the shop for the last 11yrs, have never had an air bubble issue - and in fact don't even open the bleeder screw half the time (if I do, it just makes the process only slightly faster).

When at the track and need to bleed the system without a funnel, I just simply detach the expansion tank and hold it up higher than the hood. Does the same job as the funnel.

Link to said funnel...

https://shop.advanceautoparts.com/p/...0703/9010042-p

If you want to spring a few extra bucks, there's one with a stopper in it so you don't spill any coolant once it's topped off...

https://www.amazon.com/WirthCo-32027.../dp/B007RXBSVS

[intuitivejohn]

Comparing the 2 Bleed Methods Here...Standard Vs. "Forced" BMW actually
shows both.

I ran across the bleed instructions from BMW inside their deep dive, "We're the
gnomes in the secret mountain" for the Mechanics who work on these things..
and they show both ways.

They have a "Standard Bleed"

And they have a "Super Bleed" where they hook it up to a vacuum contraption
that eliminates any and all air...It doesn't look that complicated as far as a
piece of equipment. Just BMW Retail + expensive.

Hooray for the $6.00 PumP!!!

[dnguyen1963]

Here...

https://www.google.com/search?q=drilled+out+thermostat&rlz=1C1JUFK_enUS510US510&es_sm=93&source=lnms&tbm=isch&sa=X&ei=E78aVMDONIXygwSBmoCQCw&ved=0CAkQ_AUoAg&biw=1440&bih=785#facrc=_&imgdii=_&imgrc=nUhGVdkZzhTNEM%253A%3B_Lqw3HbHM38I3M%3Bhttp%253A%252F%252Fwww.georgenitta.com%252Fthumbs%252Fthermo2.jpg%3Bhttp%253A%252F%252Fwww.georgenitta.com%252Fthermo.htm%3B375%3B304

How difficult was that? If you know how to search YouTube, you can search Google too.

[Bullhead]

Any pics on the hole location drilled through the thermostat? And do you have to use a special antifreeze? I would like to try both procedures if I had trouble with the standard. Also check this out, this guy wasn't playing he put "on tap" anti freeze to his reservoir.

http://www.youtube.com/watch?v=rP2TcA3Bj3s

[TobyB]

Drilling the t- stat seems to have been the winner for me, too-
never had any problems after that, even when I was in a hurry
and not taking much care at it...
t

[AwakenNoMore]

when i did my top end rebuild last year i had to do my first ever coolant bleed for this car. All i did in addition to the standard procedure is drill a small hole in the thermostat through the arrow, bled perfect the first time, no issues.

[raudonis]

Ask any old mechanic and he will tell you the best way to fill cooling system on many engines is with radiator hoses disconnected from the engine - filling the radiator and engine separately, then connecting the bottom hose, continue filling antifreeze separately, then connecting the top hose and then pouring in the rest of the amount - 99% of the times you will NOT EVEN NEED bleeding.

Step by step dummie procedure for m20 is on page 99 of this book: http://www.amazon.com/BMW-E30-Series.../dp/1855206781

It is on many torrent sites if you are a cheap bastard...

[shadowbethesda]

Bump... Because this pump method is the easiest way to do it. I tried everything else and could not get the system to push air out of the air bleeder valve. Really this should be a sticky. Car was not on ramps, and there was hardly any mess.

[bmwstudent]

i've never had much trouble bleeding the cooling system on my m20s. i just do the standard bleeding procedure. i guess i'm lucky...

THIS, but not lucky. Just able to follow directions proven to work time and time again.

[bangn]

Only problem with doing this with the thermostat closed is you dont know how much pressure your'e putting into the cooling system. Ive had a customer put a garden hose into the rad in order to flush out his system. Ended up blowing a waterpump gasket. The system is only ment to run at 14.5psi under pressure.

Maybe it would be better to use a radiator pressure tool for leak searching, this way you get a dial gauge to make aure you're not at risk of putting in too much pressure

[Balleristic31]

Bumping this because it is so helpful. Had an issue bleeding my car and I took a bit of compressed air to the hose Jim suggested blowing in and the coolant shot out after a big burp!