Coolant Problem....

[Lime725]

Hello everyone!

So i dealt with my 725tds e38 the Same Radiator issue as many other 7 series owners Here. I Had it changed Last year, everything worked fine, except for the Heating but that didnt Work with the old Radiator either. That wasnt a big issue for me, but Last month i Had the emmision Check Up thingie, First i didnt Pass because there was a Guy that was Well, Not friendly...so i brought the 7 series to my mechanic for repairing. I think the sway bar was a Bit damaged Not Sure though, anyways, as i changed that, my mechanic saw that my wishbones almost broke down, so He changed that aswell, after that i passed the emmision Check Up for another 2 years, but Then i Had Trouble due to the wishbones Change that the Car wasnt save to Drive, it slided on ice and snow Like a drunken dolphin. So i think that thats fixed now aswell, but now i have another issue and i have to clue What issue there could be. So when i fetched the Car from my mechanic, the Car beeped at me that the coolant wasnt enough, but since i was a couple of km's away from home i drove Back Home and watched that the Temperaturegauge didnt move. Everything went Well, after i was Home i let the Car Cool down and Then i checked the coolant and as i opened the coolant Reservoir, the coolant literally shoots Out of the Reservoir! After the coolant went down i tried start the Car, Starts perfectly fine Like always but after quite a time the coolant came Back Up in the Reservoir and spills Out of the Reservoir ( i Had the Cap Open ). Next morning after a couple of negative degrees i started the car, again, perfectly fine, didnt smoke, nothing. First i thought that the cylinder head gaskets were blown, but after that i wasnt so Sure anymore because i Checked the oil Cap and there was No Yellow foam on it neither on the oil dipstick. After i let the Car warm Up the Same issue happend, coolant spilling over the Reservoir, and with a force that Theres No coolant in the whole system in a couple of Seconds. The Most weird Part is that the Heating started to Work perfectly fine at this Point.. the Radiator hoses dont really warm Up either, theyre Just a little Bit warm.
So anyone who knows What issue i have, please reply because i havent gotten any Idea whats wrong with my 7 series anymore....

PS: i replaced at the beginning of 2018 the FSU with the Blowermotor and the IHKA, (both where broken) could that be a reason for my issue?

Thanks in advance!
Lime

[DorinDav]

Have your guy fill & bleed the system properly

[Timm]

If you take the cap off when the engine is hot the coolant will come out as the coolant temperature is above the boiling point of the coolant - so don't worry about that. Now you will need to bleed the coolant again - here's how to do it:

http://www.meeknet.co.uk/E38/E38_Ble...ing_System.htm

[Lime725]

But that it spills that much was weird for me, because i Had the Cap often Open in past years and it never spilled when the Car was hot, but i will let my mechanic bleed the system because i dont know how to bleed it at a 725tds, because i dont even find the bleeding Screw at my 530d...so if air is in the cooling system, it does that weird stuff? i thought of it before because the Car shaked a little Bit and before never, so maybe my mechanic did Something at the Heating?

Still thanks for the quick replies!

[DorinDav]

After proper fill & bleed, you can observe the system and see if leaks exist

There should be no problems & the heat should work properly.

[Lime725]

Alright, i will contact my mechanic If i have time and Then we'll do it and hopefully everything will Work Then properly.

Thanks!

[Lime725]

What reasons could there be that Theres air in the cooling system?

[Timm]

Have a read of this, it describes all the usual causes:

http://www.meeknet.co.uk/e31/BMW_M60...ing_System.htm

[Lime725]

Thanks everybody for the wonderful help! My Car is running perfectly again! Big thanks again!

[Timm]

That's great news and thanks for letting us know!

[cyclops2]

Thanks everybody for the wonderful help! My Car is running perfectly again! Big thanks again!

Great news, great bunch of guys here giving helpful info.

So what exactly did you do to get it resolved? bleed it again? If with a mechanic, what did he say about having to repeat the bleed?

[Lime725]

Great news, great bunch of guys here giving helpful info.

So what exactly did you do to get it resolved? bleed it again? If with a mechanic, what did he say about having to repeat the bleed?

Ive done it myself because i found a Post i think its Name was M62TU overheating. There was an Instruction for system bleeding. I jacked the Car Up that the Front was Higher than the Back, after that i slighty overfilled the Reservoir, Then i slowly slid the top Hose Off, it was empty but Then after maybe 2 Seconds the coolant came Out of the engine, i Put the Hose Back on, filled the almost empty Reservoir Back Up and started the Car, i let it Run warm, watched the Temperature gauge that it wouldnt overheat, meanwhile as the Car warmed Up the top hoses got warm aswell, after everything warmed Up and the coolant didnt spill, i Took the Car for a Ride, First i drove it soft but Then agressive, as i came Back Home i carefully opened the Reservoir and the coolant stayed at its optimal Level, it didnt spill Like before, the hoses got warm unlike before, and now hopefully the Car will run again fine. Thanks again!

[Lime725]

Im Back again!..... With the Same coolant issue once again....

So i Bled the coolant system once again, seems to Work fine... for the moment until it occurs again. So what could be the issue now again? Is the Air that stubborn that it wont come Out? A Friends Brother worked in a BMW Service Center and He told me that there are two possibilities...1st.. because its a BMW its a high possibility that the Air is still in there...2nd that a cylinder ist a little Bit damaged and Pumps Air Into the cooling system....
I Hope its only the Air...
So what so you Guys think?

Thanks in advance!

[acspecialists]

It may take several attempts to get all of the air out. Make sure you do not pull the cap with the car off. Only remove the cap when the system is cold and the car is running. It took me several tries before I got my system bled out.

If you think you have a blown head gasket get a testing kit for the coolant it will tell you if you have combustion contamination.

[georgebest]

Are you guys run the auxiliary pump while filling it up (by switching on heating)? Maybe the pump is not working?

[Timm]

It helps, but it isn't necessary, have a read of the below, it should give you some help:

https://www.meeknet.co.uk/e31/BMW_M6...ing_System.htm

Sent from my SM-G935F using Tapatalk

[Lime725]

What would Happen If i would Drain the coolant from engine and the Radiator? Is the Air gone Then or will it still be in there?

[Timm]

It will be all air then!

Sent from my SM-G935F using Tapatalk

[Lime725]

Oh my Bad! I forgot to Put that in : and refill the coolant? 😂

[georgebest]

It helps, but it isn't necessary, have a read of the below, it should give you some help:

https://www.meeknet.co.uk/e31/BMW_M6...ing_System.htm

Sent from my SM-G935F using Tapatalk

I agree it's not necessary but makes it easier. My pump was defective for a while and had trouble getting the air out, after replaced it no issues and takes one round only.

- - - Updated - - -

It will be all air then!

Sent from my SM-G935F using Tapatalk

LOL!!!

[setconstr]

Try Evans Waterless coolant it takes all the pressure out and you can open your radiator cap anytime hot or cold. If You follow Timm's (Meeknet ) instructions to the "T" you won't have a problem getting the air out of your system I always refer back to it whenever I have changed coolant or radiator works perfect............

[Lime725]

So when i Drain and refill the coolant, will it be gone? What about the Heater valves? Could they be a reason for my Problems?

[Timm]

No, you'll be right back at the start again - just follow the procedure, and if that fails after a few attempts then you probably have a leak somewhere:

http://www.meeknet.co.uk/E38/E38_Ble...ing_System.htm

[Lime725]

Will the instruction Work on my 725tds? Because i dont have a bleeding screw, atleast Not that i ever knew about it....

[Timm]

They must have one somewhere!