Coolant change thoughts, was it worth it?

[Hops128i]

coolant change on a 2010 128i with 65k miles:
-I only replaced 80-85% of the coolant.
-I got about 6 liters from draining the radiator.
-Only got about .5 liter from removing the hose to the water pump.
-The hoses were the most confusing part. A youtube video on a e90 shows a hose connector with a clip the flips back. I saw no such connector on my 128i. But i did see some with the clips that pull out, i was tempted to try these, but was afraid the clips were one use, so i decided to open the connector to the water pump (saw is a bavauto video clip) that used a screw clamp. Again only got .5+ liters.
-Was it worth it if i didn't remove all the coolant?

[Pig Farmer]

You got more out than most dealerships would have bothered to remove.

[The Wind Breezes]

If you've ever seen the inside of a cooling system even with your mileage...there's a ton of crap in there even if you remove "all" the liquid. Don't worry about "only" getting 80% out, that's just fine.

[Hops128i]

Good to know, the coolant change is really easier than I thought!

[Dackelone]

Like Pig Farmer wrote... you did better than most guys/shops. The important thing is to get new fluid in there, as it becomes acidic over time and looses it cooling ability. Also all the junk in the fluid that gets circulated thru out the engine. Its good to change the fluid.

Like I say with oil... but it can be said of any automotive fluid... "the best oil is FRESH oil!"...

[jaye944]

Originally Posted by The Wind Breezes

If you've ever seen the inside of a cooling system even with your mileage...there's a ton of crap in there even if you remove "all" the liquid. Don't worry about "only" getting 80% out, that's just fine.

^^^ ditto

[MightyMouseTech]

Originally Posted by Dackelone

Like Pig Farmer wrote... you did better than most guys/shops. The important thing is to get new fluid in there, as it becomes acidic over time and looses it cooling ability. Also all the junk in the fluid that gets circulated thru out the engine. Its good to change the fluid.

Like I say with oil... but it can be said of any automotive fluid... "the best oil is FRESH oil!"...

Bingo. You can actually see just how bad the acidic coolant is corroding everything. Corrosion is a flow of electrons, like a flow of electricity. You can actually measure the rate with a multimeter. Put one end of probe in coolant, other end on chassis and measure the current. The older the coolant gets, the higher the current, which means everything is corroding faster.

[Dackelone]

Originally Posted by MightyMouseTech

Bingo. You can actually see just how bad the acidic coolant is corroding everything. Corrosion is a flow of electrons, like a flow of electricity. You can actually measure the rate with a multimeter. Put one end of probe in coolant, other end on chassis and measure the current. The older the coolant gets, the higher the current, which means everything is corroding faster.

I guess in miliamps ? What would be "normal" and what would be too high(acidic level) >???

[Iron Man]

Originally Posted by Dackelone

I guess in miliamps ? What would be "normal" and what would be too high(acidic level) >???

I don't know regarding miliamps, but as for pH, since ethylene glycol is naturally basic (pH around 9-10), which is then diluted with water, so the mixture probably has a pH around 8 or so. I would think once the pH starts to become acidic (6.# or lower), corrosion starts. After that it only becomes more acidic and the corrosion increases.

Therefore, I don't think you would want the pH in the 6 range or lower (at least not for very long). You should be able to check this with pH strips.

[Dackelone]

Originally Posted by Iron Man

I don't know regarding miliamps, but as for pH, since ethylene glycol is naturally basic (pH around 9-10), which is then diluted with water, so the mixture probably has a pH around 8 or so. I would think once the pH starts to become acidic (6.# or lower), corrosion starts. After that it only becomes more acidic and the corrosion increases.

Therefore, I don't think you would want the pH in the 6 range or lower (at least not for very long). You should be able to check this with pH strips.

Yea... the best way is to use those "dip strips" and match the results with a color chart to tell you what the Ph level is.

[MightyMouseTech]

Yes, measure in milliamperes. Anything over 5 or 6 indicates time to change. Over 12 or so is really time to change.

I just googled it, most pages refer to measuring voltage. Might be more accurate. Anything over 0.4V means time to change the coolant.

[mleskovar]

Aluminum block/head/radiator/heater core, plastic water pump impeller, rubber hoses.....what's to corrode? Many modern motors have lifetime coolant for a reason. I've replaced the coolant when replacing noisy water pumps in similar motors and it was clear and looked like new at 100K+ miles. Something is wrong elsewhere if you have compromised coolant. Is the 1 Series different and I should ignore the 'lifetime' coolant? When does it start going bad and what does it look like?

[snub-nose 28]

The essence here: It is not about the coolant, lifetime or otherwise...

At 90-100k (time or, secondly mileage dependent) you Must remove the radiator, have it professionally purged/flushed.

Any aluminum block (BMW, RRover, Aston, and any non-Japanese H20-cooled) will have so much sentiment (corrosive degradation) deposited in the bottom reaches of the rad that cooling 'headroom' will vanish. You'll realize that at the most inconvenient time.

Set aside 'time/mileage' effects of thermostat, w.pump. hose scaling, water gallery scale, anti-freeze...you get the point.

Your rad will weigh many kilos more than a new 'unused' rad. It's remarkable the totality of the obstruction in the alum core after 110-120k mi.

This is what you worry about more than anything in the cooling system.

It only reveals itself on a hot day, in traffic, you have to be somewhere. But you helplessly overheat, then get to repair the heads/headgaskets for $3500.

Better to do PM: a flush for $110 with you doin' the R&R. 35% obstruction is common. (That's the engineered headroom, GONE)

Free of charge plan ahead: Just go ask a radiator shop...

[Hops128i]

Originally Posted by snub-nose 28

The essence here: It is not about the coolant, lifetime or otherwise...

At 90-100k (time or, secondly mileage dependent) you Must remove the radiator, have it professionally purged/flushed.

Any aluminum block (BMW, RRover, Aston, and any non-Japanese H20-cooled) will have so much sentiment (corrosive degradation) deposited in the bottom reaches of the rad that cooling 'headroom' will vanish. You'll realize that at the most inconvenient time.

Set aside 'time/mileage' effects of thermostat, w.pump. hose scaling, water gallery scale, anti-freeze...you get the point.

Your rad will weigh many kilos more than a new 'unused' rad. It's remarkable the totality of the obstruction in the alum core after 110-120k mi.

This is what you worry about more than anything in the cooling system.

It only reveals itself on a hot day, in traffic, you have to be somewhere. But you helplessly overheat, then get to repair the heads/headgaskets for $3500.

Better to do PM: a flush for $110 with you doin' the R&R. 35% obstruction is common. (That's the engineered headroom, GONE)

Free of charge plan ahead: Just go ask a radiator shop...

Would it be less hassle to just replace the radiator with a new one?

[snub-nose 28]

In a word, yes. Everything completed the same day . Is easier no doubt!