Here's a quiz for you DIY'ers

[Joshdub]

Originally Posted by trader4

or BMW
engineers are idiots.

Sometimes that is the case.

[J.Belknap]

Originally Posted by axgordon

It is clearly manufacturer defect.

No, it's not.

The system was overfilled.

[SlickGT1]

Not an opinion. Do some searching here first. Expansion tanks must be how BMW makes most of their money. It is also not an opinion that my 4.8is has never had an issue with the 1.4 bar cap. Yes, my tank blew up too, maybe because I overfilled it, I don't know, it was 2 years old. I replaced hoses and tank, and 1.4 bar cap. No issue since. That is not an opinion. Car has not overheated, or shown any sign of doing so. It has not burped, or purged, or whatever.

1.4 bar, had to go look at it.

Here is the GAS solution. And description of how retarded 2.0 is.
https://www.germanautosolutions.com/...12_bar_cap.php

More discussions on retarded 2.0 caps.
Got the 1.2 bar expansion tank cap from German Auto Solutions - Bimmerfest - BMW Forums

Oh and just if you are bored, just google BMW 2.0 bar cap.

[B-M-W]

Originally Posted by SlickGT1

Not an opinion. Do some searching here first. Expansion tanks must be how BMW makes most of their money. It is also not an opinion that my 4.8is has never had an issue with the 1.4 bar cap. Yes, my tank blew up too, maybe because I overfilled it, I don't know, it was 2 years old. I replaced hoses and tank, and 1.4 bar cap. No issue since. That is not an opinion. Car has not overheated, or shown any sign of doing so. It has not burped, or purged, or whatever.

1.4 bar, had to go look at it.

Here is the GAS solution. And description of how retarded 2.0 is.
https://www.germanautosolutions.com/...12_bar_cap.php

More discussions on retarded 2.0 caps.
Got the 1.2 bar expansion tank cap from German Auto Solutions - Bimmerfest - BMW Forums

Oh and just if you are bored, just google BMW 2.0 bar cap.

Hey man I'm well aware of the problems people have with cars. I'm not debating here , just stating facts. I never said the vehicle will overheat with a lower pressure cap. I said putting on a lower pressure cap lowers the overheating threshold.

In your case, was the expansion tank you installed oem or aftermarket? Was it filled properly? You stated maybe not so that kind of ends it there.

You also state that you have had no problems since you have changed to a lower pressure cap, new hoses, and tank, and everything is fine with no puking. Awesome. Now that you have your cooling issues figured out you can put your 2bar cap back on and all will be well!

[SlickGT1]

Originally Posted by B-M-W

Hey man I'm well aware of the problems people have with cars. I'm not debating here , just stating facts. I never said the vehicle will overheat with a lower pressure cap. I said putting on a lower pressure cap lowers the overheating threshold.

In your case, was the expansion tank you installed oem or aftermarket? Was it filled properly? You stated maybe not so that kind of ends it there.

You also state that you have had no problems since you have changed to a lower pressure cap, new hoses, and tank, and everything is fine with no puking. Awesome. Now that you have your cooling issues figured out you can put your 2bar cap back on and all will be well!

OE, as in from BMW at openroad.

I didn't overfill, but this is only my 4th bmw, so what do I know.

I also, did not do the radiator. Because I find that quite silly.

Again, our system cannot hold 2 bars, with brand new parts. All that plastic, especially hot, will not be able to make the cap relieve the pressure. Something else will explode first. This is the same reason BMW issued all the e30 guys 1.4 bar caps after they made a big enough stink about it. All the new BMWs also do not have the 2.0 cap.

If someone is willing to come by my garage, I will put 2 bars of air into your system, and prove a point. Even my coolant pressure tester, I struggle to pump up past 1.6 -1.7 bar. At 1.6, all the hoses feel like rocks. Not normal. Your coolant system does not operate at this pressure.

[B-M-W]

Originally Posted by SlickGT1

OE, as in from BMW at openroad.

I didn't overfill, but this is only my 4th bmw, so what do I know.

I also, did not do the radiator. Because I find that quite silly.

Again, our system cannot hold 2 bars, with brand new parts. All that plastic, especially hot, will not be able to make the cap relieve the pressure. Something else will explode first. This is the same reason BMW issued all the e30 guys 1.4 bar caps after they made a big enough stink about it. All the new BMWs also do not have the 2.0 cap.

If someone is willing to come by my garage, I will put 2 bars of air into your system, and prove a point. Even my coolant pressure tester, I struggle to pump up past 1.6 -1.7 bar. At 1.6, all the hoses feel like rocks. Not normal. Your coolant system does not operate at this pressure.

Actually bmw issued 1.4 caps to e30 owners because the old caps were failing and sticking close. When they stuck close, it would sometimes blow out a valve that would gush hot coolant into the pass footwell. So going back to my original statement, that the system works fine, IF everything is up to par. If you have a cap that is stuck, then your system is not up to par. With a stuck cap, at what pressure did the valve finally blow???

Who knows slick, maybe your 2bar cap was stuck too causing you problems?

[SlickGT1]

I doubt it. I tend to replace caps with expansion tanks. It happened once, I decided to not let it happen again.

Again, so the point is not missed. A 2.0 cap will only work, if the rest of the system can hold 2 bar. If your old plastic and rubber cannot hold 2 bar, you will blow the weakest point, not the cap. The drastic fluid leak will be way more catastrophic than a 1.4 bar cap dumping pressure.

And if you accidentally overfill, the 1.4 will dump the excess by itself, without killing a $100 expansion tank. This usually happens when the car is off, running pressure is never near that limit.

If you search for my thread, why I even decided to go to the 1.4, is because of a lot of research. After my expansion tank replacement, i got another leak. I didn't replace one of my these little ass hoses with a plastic Y fitting, it was under the throttle body. I figured it was too much of a bitch and left it for later. With new hoses, tank, cap, thermostat, the next weakest link took a hit, that Y fitting.

Also, with BMW doing the e30 recall, and switch to the 1.4 bar, they did nothing else. Cap and done. Just goes to show you that 2.0 is insane pressure, and not necessary.

The e39 guys have been aware of this for ages. Including m5. Which even for its age, is still more high performance than my 4.8.

I swear the 2 bar cap is a trick that BMW decided to play on us. New BMW caps are 1.2 bar by the way.

[B-M-W]

Hey man whatever floats your boat. "Probaly not" is just not good enough for me to base anything from. You also use the word insane and that it can't work yet they brought it back on our cars. I'm not saying I agree with this, or not. The engineers that design these vehicles are far more knowledgeable than me or you or 99% of the people that post on enthusiast forums. Acording to them, the cap is the weak link, but not when your system is 10+ years old. There's just too many variables as you stated. I don't believe any company mass producing anything (bmw included) is playing "tricks". Anything and everything will fail at some piont.

Your research (I'm guessing) most likly consisted of reading post by other forum members on various sites having similar issues. We could all do this and all find the same, but this is not good research. Good reasearch would be performing your own tests, not following the other guys bandaid fix. These forums are mostly all negitive, meaning no one is posting about the cooling system that lasted 20 years and went 300k. Were just reading about what failed and how some else fixed it. You think if you brought your X into a dealership for a cooling system overhaul that they would install a 1.4 cap?

[SlickGT1]

I'm sure they wont. How do they expect you to keep coming back for $500 cooling overhaul kits.

My car had 80k miles when this started happening. I was out of CPO due to age. My system is not band aid. Every part is OE. Even my 1.4 bar cap. Again, almost 2 years, and no issues. Like none at all.

And I keep saying insane because you are clearly not doing your own research. Read link above. GAS did a write up on why they made a 1.2 bar cap. Do more research, not forums, but companies. There should be no reason for a system running at 1 bar, to have a 2 bar cap.

There are a lot of times super smart engineers screw shit up. What you never seen a recall. The fact that no one has been burned by scolding fluid, is probably the only reason we still have 2 bar caps. I don't drink the BMW coolaid like some.

[bcredliner]

Originally Posted by SlickGT1

I'm sure they wont. How do they expect you to keep coming back for $500 cooling overhaul kits.

My car had 80k miles when this started happening. I was out of CPO due to age. My system is not band aid. Every part is OE. Even my 1.4 bar cap. Again, almost 2 years, and no issues. Like none at all.

And I keep saying insane because you are clearly not doing your own research. Read link above. GAS did a write up on why they made a 1.2 bar cap. Do more research, not forums, but companies. There should be no reason for a system running at 1 bar, to have a 2 bar cap.

There are a lot of times super smart engineers screw shit up. What you never seen a recall. The fact that no one has been burned by scolding fluid, is probably the only reason we still have 2 bar caps. I don't drink the BMW coolaid like some.

I agree it is a fact that no one has been burned by scolding coolant.