[avtopi]

How critical is to replace engine coolant. I put 80k on my focus 2000 SE, but never replaced coolant. Is replacing coolant going to help my car in any ways. The coolant level looks fine but when the car is cold and warm.

 

[iminhell]

The coolant will get acidic over time/use.
Read -> http://bioengr.ag.utk.edu/Extension/ExtProg/machinery/Articles/engcool.htm

In my opinion the best antifreeze you can buy is Polypropylene Glycol (traditional coolant is Ethylene Glycol). You can Google the differences.
The Poly. coolant is usually a jug that will say something like 'safe for pets'.

Short answer is flush/change your coolant.

 

[scrammer]

i do mine every year. its cheap insurance

 

[briandg510]

I would do what these people stated. Plus it isn't hard to do. Just make sure be environment compliant when doing this yourself by taking the used coolant to a recycling station.

-Brian