PG Coolant for Honda - need help

[Primus]

Unfortunately Original Honda Coolant is not available here, that's why all use a European blend, even Honda services. Last two years I use BMW green, but I always find some black or black-grey stuff of 1-2 mm thickness on the bottom of the expansion tank. It's necessary to notice that Aral coolant (may be Glysantin G48) that was in the system before BMW coolant was giving a double amount of this black stuff.

Now I am considering the switch my Prelude to Propylene Glycol Antifreeze, but still hesitating whether or not PG will work better. The info is quite contradictory. I head PG helps to reduce cavitation. A good reference: PG is used by Caterham.

The only PG antifreeze available on our market is designed by Lyondell/US and bottled in Europe by different oil manufacturers under their own names with reference to "Triguard" brand.

http://www.lyondell.com/html/products/markets/coolants/coolants_news/

Any idea what is this black stuff: aluminium phosphates, i.e. corrosion, drop out of silicates or something else ? And how about PG, could it help to reduce deposits ?

Would be great to hear all pros and cons for the use of PG coolants.

Thank you in advance for your help.

 

[oilboy123]

I have been using Amsoil Propylene glycol antifreeze for a few years. I like the fact that if some gets in your antifreeze (blown head gasket) it won't tear up your engines bearings.
I like the fact that it is not going to kill pets if some is spilled or leaks and animals drink it. I've had good luck with it. I have also used Sierra brand as well.
I'm sure others will chime in.

 

[Primus]

Oilboy,
Interesting point with bearings. Thanks for the info. I head that PG may change the pressure in the system. Have you noticed some impact and how about claims to decrease operating temperature ?

 

[Matt_S]

Primus,

I've never used PG coolant, but I can say this. In their owner's manuals and on their US web site, Honda specifically states that their own coolant is both silicate and borate free. If the PG coolant meets those requirements, I'd expect that you'd be OK. If you can find a source of distilled water, I think you'd be much better off, too. I'd bet the deposits you're seeing are coming from the coolant reacting with something in the water.

 

[White 03]

Primus,

From what I have read:

The pressure cap will keep the pressure the same no mater what is in the radiator.

The thermostat will keep the operating temperature the same for either so long as the system will hold that temperature.

If the heat produced by the engine is more than the radiator can give off, even with the thermostat wide open, then the EG coolant may be slightly better than the PG coolant at getting rid of heat. Haveing less coolant and more water in the mix (40%coolant to 60% water) will make a bigger difference. Plain water is apparently about the best thing made for getting rid of heat. Too bad we can't use it straight.

I don't know if EG is better than PG in a Honda. In my old Hondas I have used both and I can't tell the difference. In my newest one I will probably stick with Honda brand. Whichever you use make sure to get all the old stuff out before switching to something new. I have heard distilled water is also important.

Evans is a PG coolant designed to be used with out water; you might want to do a search on it. I am not sure I would use Evans in a Honda though it is mostly used for raceing and diesels.

 

[Primus]

Thanks for your replies. No doubts the Honda antifreeze should be used and I was very suprised to know that "my" authorized dealer in Germany never used it for service. I was explained the antifreeze they use now it's fully OK. But how about the stuff they were using before ? I have checked several authorized Honda services in our area too and no one is using required coolant. The same story with Toyota services. And no one has agreed that the coolant they are using was not OK, but to my question whether they have noticed some black-grey stuff on the bottom of expansion tanks, the anwers were affirmative.

As for Honda coolant. There are very important details to be taken into consideration. It does not contain silicates, but there should be plenty of phosphates. According to some sources in case of a started corrosion phosphates may accelerate it. I don't know whether this concerns aluminium or some other metals. Necessary to notice that despite silicates are considered as quite cheap and not too stable ingredient, they act faster than OAT. If it's true, then Honda Antifreeze is the best choice, but only if it's used just from the beginning.

Now I am afraid to aggravate the situation. Who knows what black stuff is on the bottom ? The distilled water I used is nearly perfect as could be the water from hospital applied for in vitro injections.

 

[passcord]

I have same problem in my Honda Accord,"I always find some black or black-grey stuff of 1-2 mm thickness on the bottom of the expansion tank".
And, sorry, I don't know what is it and how fix it. I don't use genuine honda coolant(of course in ready available in US just cost a $12-15), it is now honda give you 10 years warranty on factory fill, and 5 years for all next refill, but in 1995 honda required to change coolant every 2 years/30K mi. So why I have to buy overpriced stuff from honda? I used reqular "green" stuff from Prestone, I flushed/refilled after 2year, than after 4 years. The expension tank was always clear, no any black stuff. After 6 years my mechanic changed timing belt/water pump and added some more coolant, brand unknow. Well, with in a year after this I found some black stuff in the tank. I tried clean the tank, it showed up again just after couple months. Last year I drained that coolant, it was't look very bad, just little bit darker in color, I flushed the whole system with Prestone radiator flush, and ran clean water and full drain 3 times, water came out was look clean, than I refilled with "green" Prestone coolant. Well, within couple month black residue was in the tank again. I used Prestone in my another Honda for 7 yr( 3 drain/refill) and tank is still clean, well... no t-belt change on this one yet. And I guess for next t-belt change I'll bring jar of Prestone coolant to my mechanic to top off. I really not sure original honda coolant can make a difference. And I pretty sure Prestone "green" stuff OK to use in older honda.

[ August 27, 2004, 09:07 PM: Message edited by: passcord ]

 

[Primus]

Passcord,
Thanks for your info. It narrows the circle of possible causes.

 

[passcord]

UPDATE. I switched to Zerex G-05 about 2 weeks ago and so far exp tank look clear. I just could not take it anymore. About month ago I cleaned exp tank and refill with coolant, and just after 3 days all was nasty cloudy greenish. I have a V6 engine with 3 drain bolts, one on radiator and 2 on engine block. So I drained old Prestone, it was looking really bad, like no change for 4 years. I did full drain from all 3 bolts. Than I filled with water, ran for 30min, full drain again, and refilled with water and Zerex Radiator Cleaner. I drove car for a week with cleaner, than performed full drain of the cleaner, than full fill/drain with water 2 times and fill with G-05. Total cost G-05 $9.49 and cleaner $3.99, labor was free (my).