In a perfect world yes. But word on the street is that the stock 2bar cap is set too high and the plastic of the cooling system fails before the pressure reaches 2bar.

Set too high for what?:). An old failing rotting cooling system, yes. Too high for a cooling system that's up to snuff, no. I've heard of people trying to put a bandaid on there cooling system by putting on a lower pressure cap. This only hurts the system. At lower pressure, the system loses effeicency. At higher pressure, the coolant can "cool better". The system with the lower cap pressure will over heat faster and start to piss coolant out faster, overall. The overheating threshold lowers by adding a lower pressure cap. These cooling systems are great if kept up to par, problem is, people don't or don't know how too. Example: http://www.xoutpost.com/bmw-sav-foru...ing-screw.html

:iagree:

Bullshit. Out system does not run anywhere near 2 bar, unless it overheats, and if it overheats, you are screwed. I have been running my e30 cap 2 years now no issue. None of the component in our cooling system were designed for 2 bar. 2 bar cap is just insane. There were recalls on numerous BWM to install a lower bar cap.

Look at the example above. Mixture was off and the tank went boom. What happened to that cap, nothing. It didn't do shit, another component of the system failed. A brand spanking new component. My cap would have vented the steam way before that tank blew up.

The expansion tank blowing up is nothing either. How about next time the damn rear 1.5" hose blows up. You will empty out your system before you can pull over.

Thank you g300d, B-M-W, J.Belknap and trader4!
As a first who answer this quiz, I intentionally didn't elaborate to see how others will respond. Of course there are many variables to consider in every cooling system component failure, but based on the information provided by the OP -- It is clearly manufacturer defect.

"Bullshit and insane"... Your simply stating your opinions. I just stated facts about how a cooling system operates:)

Exain how a German engineer arived at a 2 bar cap, if the system wasn't designed for 2 bar, by a German engineer?

Sorry guys, not a manufacturer defect. I know it appears so but it's not. As a matter of fact, I lost three tanks by over-filling. First one started leaking when I started working on the car (tiny cracks on the bottom). The replacement after that failed the same way. Second replacement started leaking on the joint of top and bottom sections of the tank. All the while I used to fill the tank until the floater was all the way up before I realized my mistake!:doh: Three expansion tanks lost in a span of 2 or so years!

No, it's not.

The system was overfilled.