what kind of coolant?

[almagg]

97 buick skylark
v6 3.1ltr

refurbished engine put in a few years ago and the mechanics put in the prestone universal yellow. haven't had any problems with it.

i need a new coolant reservoir and am also going to change the hoses so i am wondering if i should put in regular green coolant. previous engine had intake gasket problems so i am reluctant to put in dexcool.

stay with the yellow?
go with the green?

[MagicRat]

Do not use Dexcool. It has plasticisers in it that are hard on gaskets and rubber components. It has a bad reputation for a number of technical reasons.

Generally speaking you are best to avoid any coolant labelled "extended life", for various reasons. Some are like Dexcool and are known to have technical issues. Some use different formulations that are not intended to be mixed, making "topping-up" a problem if you don't have the right stuff handy.

It's safest to use conventional green coolant. It has silicates. You cannot mix it with "extended life" coolants, but otherwise its pretty much foolproof. It's widely available, making "topping-up" easy and the same formulation is sold under many different brands. You can use it in pretty much all engines, regardless of whether they have aluminum, iron or brass components. (You can't use "extended life" coolants with brass rads, as I recall)

The downside is you need to change it every 2 years or so. But that's it,

Some Prestone yellow anti-freezes are virtually identical to the green stuff. Some are labelled "extended life" so its tough to tell whats in your car right now. But chances are its due for a change. Just flush your system with fresh water to get rid of the old stuff and use distilled water 50/50 with the green silicate coolant and you will be fine.

Heres an excellent article on coolant choices:

http://www.mastertechmag.com/pdf/200...antifreeze.pdf

[almagg]

thanks for the info.

i don't know what kind of yellow was originally put in but when i got the initial leak in the reservoir i topped it off with Preston yellow - extended life (not knowing better) and which i guess is the 'prestone gold' mentioned in the article), and is the same formula as dex-cool.
i used about half the jug and the label shows it does contain '2-EHA (sodium 2-ethyl hexanoate)' which seems to be the not good stuff.

luckily that was less than a year so i will definitely do a flush and go with the green.

thanks again.

[HotZ28]

97 buick skylark
v6 3.1ltr
Sorry, but I thought 1972 was the last model year for the Buick Skylark. Anyway, this thread was relocated here from "Maintenance Tips & Procedures", where these questions, or answers do not apply.