MGB & GT Forum

1972 MGB GT — pretty much stock

I don’t think I did anything wrong, but I thought I would get opinions from the forum. I never really understood the ingredients in anti freeze, but do understand the concept/ function.

I noticed I needed to top up my radiator. I did not have the Prestone yellow 50/50 antifreeze left over from the last time I did a flush. I did have some Honda specific blue 50/50 left over from the last time I flushed my Honda element, so I topped the cooling system up with the blue 50/50.

This time of year, I probably should have just added distilled water, but I acted before I thought about it.

Question:
Should I let it ride or change out all the antifreeze before I intended to. I was planning to change it out when winter was approaching in the fall.
Thanks in advance for your thoughts
Andrew

Personally I wouldn't mix the two

I would stay with old fashioned green anti freeze

X2

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Des
Stay safe.

X2 or perhaps X3? Many years ago, when I was ignorant on antifreeze, I mixed the green with orange. About 75 miles later, I had orange foam everywhere and it was starting to stick to my windshield. And the engine began to overheat. IMHO, you should drain what you have and put in the green sooner rather than later. The Honda stuff is tailored to Honda engines and none other. Sometimes the chemicals in the antifreeze don't get along with another type.

I would rather state an Ethylene Glycol antifreeze because the colour means nothing. The original factory installed Smiths Bluecol which was blue (funny that) but ethylene glycol antifreezes can also be green (common) and fluorescent green. These antifreezes are perfect for our cars, they both raise the boiling point and lower the freezing point, they are good to use even in an area that never freezes due to the higher boiling temperature.
The other type of anti freeze is commonly called OAT (Organic Acid Technology) and have been in use since before the turn of the century, however there are several different variants, ie OAT, HOAT,
P-HOAT, SI-OAT. They are not manufacturer specific but the different types shouldn't be mixed. They give far greater protection against corrosion on aluminium engines, radiators and heaters.
Here is a great source of info into the different types and where to use them; https://www.valvolineglobal.com/en-eur/all-you-need-to-know-about-coolants/

"Personally I wouldn't mix the two
I would stay with old fashioned green anti freeze"

As I understand it, there are two types of antifreeze - traditional Ethylene glycol mixes and OAT specification antifreezes. They both contain ethylene glycol as the base but the newer OAT ones have different additives designed for modern cars. The two are not compatible.

I use 4Life coolant which I have found excellent over many years use. You don't dilute it, just pour it in neat. That seem expensive, but it lasts just about for ever and gives tremendous protection against boiling - it's claimed to not boil under 180C. The 4Life in my BV8 has not been changed for over ten years and is still clean and effective, and that engine runs very hot in summer. The red colour is an indicator and if it turns yellowish you probably have a blown head gasket, so that can be useful too. https://www.demon-tweeks.com/uk/4life-advanced-engine-coolant-7001361/

In the color world…yellow and blue = green! But as has been noted, color means nothing at this point after mixing.

Personally, I Stay with the old original ethylene glycol (yellow/green). It’s what the cars came with in my area of the country. Change it every two-three years. We do freeze here but even so something needs to be used for corrosion / lube purposes. I would never run straight tap water unless for temporary test purposes.

Brian W.

Thanks all

I will change it out today.Never even started the car since adding the additional coolant.

That said— just to clarify— if my Honda coolant is ethylene glycol based, would the drain/refill still be recommended?

I am draining my system— just trying to learn a little too!

Be well
Andrew

Pretty basic for iron engines/heads & copper/brass radiator. It gets quite confusing with a mix of parts. Some have an aluminum radiator with the OEM engine, some have an aluminum head on their iron engine. Some of us have an aluminum engine/head/intake/water pump with a copper/brass radiator & heater core.

I use this; https://www.amsoil.com/p/amsoil-propylene-glycol-antifreeze-and-engine-coolant-ant/

Product https://amsoilcontent.com/ams/lit/databulletins/g1156.pdf

I point out that colour does signify the type of antifreeze, but the colours used seem to vary depending on the region. They may also vary by brand. Here in North America, green does typically mean plain old-fashioned antifreeze that we've been using for decades. E.g., traditional Prestone is green.

And even the engine manufacturers cannot quite agree on the additives required for their new engines. Hence, there are specific antifreezes for specific brands. Typically the newer antifreezes are intended for aluminum blocks and aluminum heads but after that there are differences.

There are articles on the net about the additive requirements specified by various manufacturers (to keep their warranties intact).

You probably won't have a problem from mixing the two formulas, but why chance it? Drain and replace with an older formula anti-freeze (intended for cast iron blocks and heads) and mix it with distilled or deionized water. You can also buy the pre-mix and avoid the bother (although it does cost more than buying the water and concentrated antifreeze separately).

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Terry Ingoldsby
terry.ingoldsby@DCExperts.com

Also, as has probably been sited - Ethelyene-glycol type fluids are poisonous so don’t leave any open pans laying around so animals can’t get to it. Only the “ Sierra (sp)” brand is non-toxic I believe. Others will know.

Brian W.

I just went through this, and my research said NOT to use distilled, but de-ionized water.

Well, I bought two gallons of Prestone green , but when I compared the ingredients both products appeared to be essentially the same. Sorry for the incomplete picture, but I am sure you see what I see.

I will change the coolant, but it sure doesn’t appear that the Honda blue is that different from the Prestone green.
Be well
Andrew