Coolant alternatives/upgrades to save $$$

[BrandC]

Okay all, I've been doing some homework. I have some generic green coolant in my M42 and I don't want it there anymore. I am going to flush it completely.

The BMW coolant we use in our E30's from the dealer is equivalent to VW's G11 (Blue coolant), which is phosphate free. Since the switch to OBD2, many manufacturers have switched to a phosphate AND silicate free coolant. This is G12 for VW's.

I upgraded to a cheap off the shelf alternative to G12 called "Prestone Dex-Cool" in my '95 GTI VR6. It's about $10 a bottle at Autozone. I'm pretty sure I can do the same for the M42 since BMW coolant is equivalent and it is much cheaper and less likely to clog/gunk up our coolant system.

My question is what are some ways to completely FLUSH (not bleed) all the green generic coolant in my M42? I want to flush every last drop of coolant out in my M42. I read a VW TSB that said upgrading to G12 from G11 meant completely flushing the system before b/c G11/G12 mixing makes a gunky mixture.

So here's what I'm thinking:

1. Drain as much coolant as possible
2. Fill the cooling system with distilled water and a radiator flush, bleed, drive around for 1-2 days.
3. Fill with distilled water/Dex-cool mixture.

or

1. Drive the car around at operating temperature.
2. Wait so the engine is not burning hot, drain the coolant while the thermostat remains open. (leave drain plug open too)
3. Take a garden hose and fill it with water and let the water flush out any remaining coolant.

Let me hear what you guys think. TIA.

[Choking Hazard]

I did use the spendy blue BMTurn heat on full
Drain rad at discharge valve on bottom left.
Refill with tap water.
Drive until thermo opens, heater produces hot air.
Drain/ repeat.
Drain/ repeat.
For last refill, I left the cap off the rad with garden hose filling the reservoir, opened the drain cock again and let it run for awhile.
When the discharge looked completely clear, I drained once more and filled with distilled water and coolant.  Unfortunately, there will be the tap water in the heater core mixing in the new stuff, but I think that risk has gotta be pretty minimal.

[ecpreston]

I used Dex-Cool in a Fiero years ago as that was the recommended thing at the time and didn't have any problems with it. But I've heard nothing but complaints more recently from people who have tried it on other cars. BMWs included. And yes, it's a pain to have to flush out the whole system.

FWIW, the correct, blue, BMW stuff is maybe $15/bottle last time I checked? If I were going to flush the system, I would go with this as the price difference is nothing. From what I understood, Dex-cool (orange) is NOT the same makeup as the blue stuff, but I could be mistaken.

A recommendation though, the regular Prestone, yellow bottle, extended life stuff, you can find it anywhere, is designed for mixed material cooling systems. It's made to be added to any system, any coolant, it's yellow in color and phosphate free. I've used it on my m10 BMWs and the E36 I had a few years ago, and have had no signs of trouble with it. And you don't even have to flush out all the green stuff, although getting rid of most of it would be ideal. I think it is $8 or $10 per bottle.

[Alpine003]

I used Dex-Cool in a Fiero years ago as that was the recommended thing at the time and didn't have any problems with it. But I've heard nothing but complaints more recently from people who have tried it on other cars. BMWs included. And yes, it's a pain to have to flush out the whole system.

FWIW, the correct, blue, BMW stuff is maybe $15/bottle last time I checked? If I were going to flush the system, I would go with this as the price difference is nothing. From what I understood, Dex-cool (orange) is NOT the same makeup as the blue stuff, but I could be mistaken.

A recommendation though, the regular Prestone, yellow bottle, extended life stuff, you can find it anywhere, is designed for mixed material cooling systems. It's made to be added to any system, any coolant, it's yellow in color and phosphate free. I've used it on my m10 BMWs and the E36 I had a few years ago, and have had no signs of trouble with it. And you don't even have to flush out all the green stuff, although getting rid of most of it would be ideal. I think it is $8 or $10 per bottle.

BMW coolant has gone up in price. Anywhere from $20-$30 depending on what dealer you get it from.

Prestone extended life(yellow color) is a good alternative for BMW's as it is phosphate free and compatible with older coolant. I probably have a 30% green and 70% yellow mix in my car now. I recently flushed my coolant again and should be close to 100% yellow. This stuff is $10 from Autozone.

[ecpreston]

BMW coolant has gone up in price. Anywhere from $20-$30 depending on what dealer you get it from.

:eek:

[dino245]

becareful with the G12 it tends to develope leaks all through the cooling system and becomes crusty where ever it comes out. If your cooling system seams tight this stuff will find the holes. I have exstensive experiance with this stuff from 7 years at the VW/Audi dealers and hated this stuff. Consider this, if you have to add coolant and you are in some place remote you may not be able to add any thing but water. I have seen what this stuff looks like when it turns to mud in a cooling system and how an engine will over heat from lack of flow.

The G12 is suposedly a life time fluid but the risk is too great to justify saving a few bucks on traditional coolant.

Just my 2 bits.

[D. Clay]

As important as the coolant is the water. De-ionized or distilled. You can buy pre-mixed to carry in the trunk for emergencies.
All of the US makers say that you need phosphate free coolant because of the minerals in the water in Europe. That it's not really necessary in North America due to different water. You only need a type approved for different metals and plastics in modern cooling systems.
I don't know if that's true about European water but all US makers say it on their websites.

[BrandC]

Dino245: I don't need to use G12/Dex-cool, it's just a cheaper alternative. I might just stick to some regular phosphate free coolant. I know exactly what you are talking about with G12 and it finding its way out through leaks and crusting.

Choking Hazard: That sounds like how I flushed my G11 in my VW to upgrade to G12. I made sure it was just completely water, but a little tap/garden water in my system is fine.

The reason I am looking into a complete flush is because I'm not sure exactly what coolant the previous owner put in. I am not looking to be a cheapskate, I just plan on doing lots of mods that might require me to drain the coolant. I don't want to spend tons of $$$ each time.

[ClubSport]

If you drain it into a clean container, you can just dump it right back in when you put the engine back together.  No need to throw it out if it's got life left in it.

[RED IS 91]

I used zerex phosphate free . Good enough for Mercedes, it's good enough for me . I got my distilled water from Walmart .
You have to remove the drain plug in the block to remove all or most of the old coolant .

[BrandC]

Can anyone point out exactly where to drain on the block?

[Alpine003]

I used zerex phosphate free .

Now that I think of it, I think this is what I used. I got mixed up with Prestone. Zerex is in a Gold colored container, right? They specifically say on the back that it's compatible with BMW. If they can make that kind of statement in writing then I think you should be safe.

[BrandC]

Alpine003: That's the thing, I don't know what type of green coolant is in my cooling system. With that said, I talked to another guy on BFC and he said the Zerex G-05 (gold bottle) was compatible with regular joe green coolant. So now I'm not too worried about completely flushing it. I would rather do it just to be safe anyway though...

[arthurc]

Can anyone point out exactly where to drain on the block?

Right-rear of the block, below the exhaust manifold.  I *think* it's bolt 5 in this digram http://realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_1154&hg=11&fg=10

[RED IS 91]

Now that I think of it, I think this is what I used. I got mixed up with Prestone. Zerex is in a Gold colored container, right? They specifically say on the back that it's compatible with BMW. If they can make that kind of statement in writing then I think you should be safe.

yea ,that's it ........