why is the BMW coolant system the way it is?

Originally Posted by 2003 325i

<- original coolant system
<- original window regulators
<- original fuel pump

Winning.

Original brakes, at 120k+ miles.
Window regulators
Cooling system, except for ET
Original plugs and coils
Original VCG
Original suspension
Not proud of any of that....

I have replacements on hand for every single one of them.

Originally Posted by 2003 325i

<- original coolant system
<- original window regulators
<- original fuel pump

Winning.

Until you're left stranded on the side of the highway in the cold. Have fun with that

Originally Posted by lcoleman

Pretty much every BMW since the mid 90s or so has been plagued with window regulator issues. To suggest that parts fail because they needed lubrication (jokingly or otherwise) pretty much confirms they are poorly-designed and/or poorly-made.

...no. PV=nRT so temperature and pressure are directly proportional. And pressure is pressure, with or without the air in the system.

Your last statement is true but misleading. If the system has no air (meaning it is a solid system, all water), then a small increase in temperature can create huge pressures. Water does change density with temperature a little bit. However water hardly changes density with pressure. If you heat a solid system, you will blow it up very quickly. For example, given constant volume, water at 1 atm and 25C heated to 40C will then be at 110 atm pressure. That is insane. i.e. overfilling the cooling system WILL blow up your ET.

Originally Posted by WDE46

... That is insane. i.e. overfilling the cooling system WILL blow up your ET.

Only if the pressure relief valve in the expansion tank cap fails. Otherwise, it will vent the excess coolant.

Originally Posted by joegr

Only if the pressure relief valve in the expansion tank cap fails. Otherwise, it will vent the excess coolant.

Correct. My calculation was obviously with no pressure relief. It was just to demonstrate how powerful a solid system of water is (and dangerous).

Originally Posted by 2003 325i

<- original coolant system
<- original window regulators
<- original fuel pump

Winning.

+1 to that. Also same year, model and color car. I think this is saying something lol.

Originally Posted by lakedude90

+1 to that. Also same year, model and color car. I think this is saying something lol.

Orient blue ftw. Though I have a Coupe. I also have hte original cooling system. How many miles you got? I'm at 66k.

just crossed 71k

Originally Posted by EverydayGetaway

Until you're left stranded on the side of the highway in the cold. Have fun with that

with an overheating engine and four windows that won't roll up.

Originally Posted by lakedude90

+1 to that. Also same year, model and color car. I think this is saying something lol.

that you don't do PMCS?

I just havent done it yet more or less. I have plans to. I just have to get all the parts to do it. It will be done by the spring time.

Race car mudafaka

Originally Posted by MJLavelle

Find me a car out there that does not use plastics in 90% of their cooling system. I have posted extensively about why plastics are NOT a cheaper solution for car makers, and why they like to use them anyway, but I will just give you the broad view:
- The capital costs for plastic molds are HUGE. The one for the thermostat housing would easily be a $750k mold. And you can't just have one. They probably have a dozen. And when they stop making e46 thermostat housings, that mold is just scrap steel, because the only thing it can do is make e46 thermostat housings. Not to mention, the molds wear out. There is a limited number of parts that can be made before it is too worn to produce the dimensionally correct part. Plastic is abrasive to the mold. That single part has probably cost BMW millions of dollars in molds alone.

So, why use them?
- The parts come out of the mold ready to use, for the most part. No machining, no plating, painting, anodizing or other finish required. The same part made from aluminum is labor intensive. It requires casting, then machining operations, then finishing operations. Each of these steps introduces the chance for human error, scrapped parts loss, and dimensional variances, not to mention transportation from one facility to another. But, a part made in a properly operated plastic mold will have almost zero scrap loss, and will come out of the mold complete, and dimensionally correct, each one the same as the other. There is almost no dimensional variance.

Now, you are correct in stating that they will not last like metal parts, but they will outlive the warranty period. And yes, that is all they care about. But this has added a new type of preventative maintenance to cars, because you now have to replace parts based on age, and not because of a failure. It is now just a fact of life that this is the way things will be from now on. It sucks, but it will not stop. In fact, it will expand to other parts as time goes by.

Thanks for broadening my view on the matter..

But I do find the conventional cooling system to be much more reliable. So much easier to bleed as well.

Originally Posted by LeMansteve

Lots of info here that will probably answer why European manufacturers make cars they way they do:

http://ec.europa.eu/environment/waste/elv_index.htm

Ooo, would have never thought this..

Originally Posted by EmFiftyFour

Originally Posted by LeMansteve View Post
Lots of info here that will probably answer why European manufacturers make cars they way they do:

http://ec.europa.eu/environment/waste/elv_index.htm



Ooo, would have never thought this..

When do the gov regulations for our protection get to the point where the fees for a car or whatever get so high that they surpass the cost of the car? Only fifty people in the country will be able to afford cars, and they'll all be gov employees!
At some point it's beyond stupid.

Originally Posted by Stinger9

When do the gov regulations for our protection get to the point where the fees for a car or whatever get so high that they surpass the cost of the car? Only fifty people in the country will be able to afford cars, and they'll all be gov employees!
At some point it's beyond stupid.

I see your point, but regulations like these are okay. Sometimes these laws can be good as it forces manufacturers to invent new processes and materials for their cars. In some segments, progress would stagnate without government intervention. For example, in the US cars are going to be required to acheive 35 mpg in the future. This is pushing manufacturers to build engines capable of this. At first they complain, then they engineer around it. Just like catalytic converters in the 70s. Cars made in that era make next to no power (the 70s Corvette was slow as ****). However, today, engines are so much better and cats are too, that we make more power with 90% less emissions. I'm not saying the govt can't go too far, but for now, the practices are good.

Originally Posted by lakedude90

just crossed 71k

I have 109K+

Originally Posted by NOVAbimmer

that you don't do PMCS?

I don't PM isht that doesn't break. Don't have cash to waste and if I did, I still wouldn't waste it.

I never said I don't flush coolant/diff/trans every 50000 kms and do my oil changes every 10-15K kms. I take care of my car, but if it ain't broke, don't fix it. Mechanic FTW, I have a good handle on the pulse of my car.

If I'd have JFOJ'd or Mangoed as those "gurus" suggest, I'd have thrown away somewhere in the neighbourhood of 2 grand by now and not had my car running any better than it is in the current condition.

P.S. My Victor Reinz (OMG!!!!!11) VCG isn't leaking either some 1.5 years later, should I post in that thread too?

This board like any other car board has an epidemic of people with no mechanical skill who all think they can/should work on their own vehicle. There are few that can/should as evidenced by the multitude of inane/assinine threads that exist. On top of that we have others telling these very same people who don't know WTH they are doing to replace isht at crazy intervals. These people are either egomaniacs who think everyone should follow their (mostly unfounded) advice, or secretly parts dealers or work in the auto parts industry. I vote for the former.

Happy motoring (makes me think this should be engineing... more correct).

Originally Posted by NOVAbimmer

with an overheating engine and four windows that won't roll up.

I'll keep waiting, you keep spending, we'll see who's pocketbook comes out ahead ok?

For interest's sake do you have AAA or anyone else that will give you a tow that you subscibe to?

cheap fix is a good fix.
me and 2003 325i are basically townmates. great minds think alike.

Originally Posted by 2003 325i

I'll keep waiting, you keep spending, we'll see who's pocketbook comes out ahead ok?

For interest's sake do you have AAA or anyone else that will give you a tow that you subscibe to?

I have roadside assistance, that doesn't mean I'm OK with breaking down. Breakdowns don't happen when you expect them to, they happen randomly. What if you're on your way to an important meeting or there's an emergency then your car leaves you stranded on the side of the highway? All because you needed to thicken your pockets? Sounds pretty stupid to me... but keep thinking you're smarter then the cautious people, I find it amusing