Difference in coolants

[2KBMW]

Hey guys. I'm just starting to read
posts on coolants now and I want to
know what the differences are between
all the coolants available. I changed
the coolant on my BMW at the dealer
and it was blue. My other GM cars have
the orange dexcool. Can you mix the
blue BMW coolant with other types like
Prestone?

 

[Matt_S]

Make sure you read this article. It explains the differences well. I can't speak for BMW's coolant, though. The safest way is to replace it with the same type, although you would need to go to the dealer to get the BMW blue stuff. If you don't want to got that route, a complete flush, followed by your coolant of choice (Prestone Extended Life is a good brand, BTW) is the next best option.

 

[Jimbo]

That article does not address BMW G-48 cooolant directly. After reading that article and the Zerex spec sheets, I went with G-05 for my BMW, partly on the basis that Mercedes and BMW probably use similar materials in engine construction.

 

[gmttr1]

Jimbo:
Are you the same as the Jimbo323i on RF forums?

As for the original question, there are 3 types of coolants: Inorganic (a.k.a. conventional or IOT), Organic (a.k.a OAT or Dexcool et al) and Hybrid Oat (a.k.a HOATs). The G-48 Glysantin product and the G-05 BASF products are VERY similar. They are both HOAT products and emphasize the use of very low silicates and the non-use of phosphates. The only difference as far as I can see is the very long and established time-tested performance of G-05 in Mercedes cars (which BTW have rock-solid cooling systems). While I have no reason to allege that the coolant G-48 has anything to do with this, one must contrast that rock-solid proven performance of Mercedes's overall cooling system against the known failure-ridden nature of BMW's cooling system. Yes, we know the plastic radiators break, the water pump bearings fail, the thermostats routinely get stuck et all. Does this have anything to do with G-48? I don't know. What I do know is that G-05 has a virtually bullet proof record in a very identical car (Mercedes). That and the very cheap price of G-05 make it a great choice as far as I am concerned.

BTW, never ever confuse the blue color of the coolant as proof-positive that BMW coolant was used. Many if not all BMW dealers will use the blue-colored Peak coolant for a drain and fill when it is a cash-pay customer job, unless the customer specifically asks for and pays extra for BMW coolant. I am not making this up; this is a known fact. Of course, all warranty work would necessarily be done with BMW coolant.

Also, to address your question about mixing. From all the info I gathered, the two fluids are fully compatible, but I don't like "contamination" so I gave the BMW coolant a nice kick-out with distilled water before going over to G-05.

 

[2KBMW]

Gmttr1. BMW coolant was used because
I saw the mechanic put it in. But how
do you know which companies make G-05
or G-48?. What G-05 coolant did you use?
As far as BMW cooling issues, didn't they
have a problem with plastic impellers in
the water pump and were replaced with metal
ones to correct the problem?

 

[gmttr1]

I used the Zerex G-05 as have several other Bimmer owners I know.

I was not trying to imply the BMW cooling issues were caused or even related to the G-48 coolant, just was mentioning them to illustrate the checkered nature of the cooling system in general. BMW's cooling system problems, specially on the E39 540 go way beyond just cheesy water pumps. Radiators, expansion tanks, thermostats, cooling hoses and water pumps are all very failure prone and are replaced at 60K as preventive maintenance, assuming they have lasted that long!!

quote:

---

Originally posted by 2KBMW:
Gmttr1. BMW coolant was used because
I saw the mechanic put it in. But how
do you know which companies make G-05
or G-48?. What G-05 coolant did you use?
As far as BMW cooling issues, didn't they
have a problem with plastic impellers in
the water pump and were replaced with metal
ones to correct the problem?

---

 

[pbm]

Does anybody know if PEAK Global Extended Life A/F uses 2-EHA.

 

[Ray H]

Good question. Peak doesn't list the CAS number or chemical name of the hydrated organic acid salt in the online MSDS for Global Extended Life antifreeze/coolant, but the product data information does state that phosphates and reduced levels of silicates are present. Phosphates and "HOAT" technology... Sound familiar? If this Peak brew isn't a G-05 clone, it certainly reads like it's awfully close. (It's also dyed amber.)

 

[Ray H]

Addendum to my post above:

1> G-05 is phosphate-free
2> According to the back of the jug at Pep Boys, the organic acid salt in Peak Global Extended Life antifreeze/coolant is sodium benzoate, not sodium 2-ethyl hexanoate (2-EHA).

 

[Jimbo]

quote:

---

Originally posted by gmttr1:
Jimbo:
Are you the same as the Jimbo323i on RF forums?

Yes, we know the plastic radiators break, the water pump bearings fail, the thermostats routinely get stuck et all. Does this have anything to do with G-48?

BTW, never ever confuse the blue color of the coolant as proof-positive that BMW coolant was used. Many if not all BMW dealers will use the blue-colored Peak coolant for a drain and fill when it is a cash-pay customer job, unless the customer specifically asks for and pays extra for BMW coolant. I am not making this up; this is a known fact. Of course, all warranty work would necessarily be done with BMW coolant.

---

No, I am not Jimbo323i.

The coolant itself has nothing to due with bad OEM water pumps and radiators, but these cars are designed to warm up very quickly and seem to be on the ragged edge of overheating most of the time. When my water pump failed, it went from normal to full hot on the gauge in less than one mile of driving. I once drove a Ford Fiesta over 20 miles without a water pump drive belt and the engine was not damaged.

Zerex does make a G-48 coolant, sold only in bulk, no retail gallon jugs, that is probably used at some BMW service centers.