Engine Cooling system QUESTION.

[sneekens]

CAR: e34 535i

I recently changed everything in my engine cooling system, from radiator to expansion tank, i have a few questions:

1) after bleeding, i opted to use my old reservoir cap which says 140 on top (1.4bar?), but after turning the engine off, coolant spilled out through the hose of the expansion tank. I bled my cooling system again but now I used the newer cap (200 marking on top, 2.0bar) but i was hesitant to use this since most people say that using the 140 is better, but then, cooling spilling didn't happen again. so which should i really use? i read somewhere that the 200 was recalled for a time...?


2) after observing the cooling system, i saw brown rusty like color flowing IN my expansion tank, where did this come from? it doesn't seem normal but everything works fine. coolant level is still the same.

Please enlighten me!

thanks!!!

[shogun]

If you could add to your signature the engine type and model year or even production month/year, that would be very helpful for us to help you.
VIN decoder is on my website below where you find all the details.
M30B30, M30B35, M10, M50....l engine
And of course the country version/spec is often important.

[sneekens]

If you could add to your signature the engine type and model year or even production month/year, that would be very helpful for us to help you.
VIN decoder is on my website below where you find all the details.
M30B30, M30B35, M10, M50....l engine
And of course the country version/spec is often important.


oops, forgot about that... edited..:)

[uscharalph]

Radiator caps wear out. You allways want to use a new one.

Did you change the hoses? Flush the engine block?

[sneekens]

Radiator caps wear out. You allways want to use a new one.

Did you change the hoses? Flush the engine block?


I did use the new one, but should I get a new 1.4bar reservoir cap or my new 2.0bar cap? I did change all hoses... how do i flush the engine block?

[Chris'91'525i]

how do i flush the engine block?


I explain how i flush the block, heater core and radiator in this post, scroll down to reply #5.......

http://www.bimmernut.com/forum/showthread.php?p=214036#post214036

[sneekens]

I explain how i flush the block, heater core and radiator in this post, scroll down to reply #5.......

http://www.bimmernut.com/forum/showthread.php?p=214036#post214036


hi chris, i did what you did. :) but the thing is, after a day the brown thing showed up. Im sure it came from the block since i changed all of my cooling system. oh well, I might do this again soon. I just hate to see the brown stuff inside my expansion tank, this is the reason why I bought a new one.:(


Btw, what reservoir cap should I use? 1.4 or the 2.0 bar?


thanks!

[Paul in NZ]

it is difficult to get ALL the old stuff out....thats why all the "old timers" in the "flush" thread used chemicals and flush flush flush.....

[Mitch90535im]

Could it be oil?

[sneekens]

Could it be oil?

hmm, but my engine oil level is still the same for over 3000kms after my last change oil. what produces the rust like color in the cooling system? can anyone confirm this?

[DaveVoorhis]

If the coolant itself is rust-coloured, it's probably old rust deposits from the block that were dislodged when you changed the coolant. If there are coffee-with-milk coloured blobs floating on the surface of the coolant, that's probably oil; a very small amount will make a fair number of blobs.

[sneekens]

If the coolant itself is rust-coloured, it's probably old rust deposits from the block that were dislodged when you changed the coolant. If there are coffee-with-milk coloured blobs floating on the surface of the coolant, that's probably oil; a very small amount will make a fair number of blobs.


good thing its only rust. whew... no milkshake like or cofee with milk colored blobs :D

thanks guys!

[Tiger]

I would use the 1.4 bar radiator cap only... the reason why BMW did this is because the 2.0 bar is too high that BMW owners were getting scalded when heater core burst. It is unnecessary to have such a high 29 PSI radiator cap.

Only reason we want some pressure is to raise the boiling temperature... but 29 PSI is rediculous.