E46 Fanatics Forum banner
  • Hey everyone! Enter your ride HERE to be a part of October's Ride of the Month Challenge!
1 - 15 of 15 Posts

·
Registered
Joined
·
41 Posts
Discussion Starter · #1 ·
Hi guys i have surveyed the forum on this matter and most replies were a year ago, so let me reignite this topic.

My expansion tank exploded on me a week ago and i have been googling ways to reduce the risk of such from happening again.

Here is what i have found :
1. lowering coolant valve cap from 2.0 bar to 1.4, or 1.2 bar.
But i am also aware by doing so will reduce the boiling point of the coolant due to the lower air pressure.

check out this website guys :

https://www.germanautosolutions.com...12_bar_coolant_cap/product_bmw_12_bar_cap.php

it stated that 1.2 bar is the best pressure for our cooling system?

what do you think?
 

·
Registered
Joined
·
496 Posts
I think the general consensus is that the tank becomes weak due to age and needs to be replaced periodically as a PM.

so, how old was your tank?
 

·
Registered
Joined
·
690 Posts
replaced mine on a 330ci with a 1.4 bar cap a year ago as I would rather have it vent out fluid than burst something also did temp gauge mod so far no troubles or leaks
 

·
Administrator
2004 330Ci 115k miles japan red
Joined
·
16,960 Posts
I also have the 1.4 bar cap and modded temp gauge mapping on both E46's and the wife's E39. No problems at all for several years now.
 

·
Registered
Joined
·
29,904 Posts
The way you don't let it happen again is by maintaining your cooling system. I went for years on stock cap, autoX, track, heavy hot traffic. Never a single problem. Temps always perfect.

For giggles I replaced the cap with the lower one just cause I like to replace my cap in between ET service intervals and didn't notice a difference.

To summarize, don't think the cap is an end all be all to cooling problems. If you don't maintain the rest of the system, cap nor no cap you'll be fvcked.
 

·
Registered
Joined
·
873 Posts

·
Registered
Joined
·
41 Posts
Discussion Starter · #14 ·
u guys are amazing, thanks heap
 
1 - 15 of 15 Posts
Top