Or does it take the "special" GM stuff?  Have your typical antifreeze I'd like to put in it, but was wondering if I can do this without hurting the engine (3.8 liter).  Car was my mother-in-laws with 75,000 miles on it.

Wizards, what say you???

Thanks.

vmax84

Some of the newer antifreeze you can mix,but do not mix regular with the newer dexcool.

Is it orange, or is it green?

If you have dexcool it'll say all over the place "DONT FUCK WITH THIS!!!"

If you've got a plain ol' rad cap with green shit within, then its old school antifreeze and don't worry. Anyways, go get your oil changed.. they'll top off all your fluids, including radiator, and you can then ask em if it's regular or dex.

Prestone and Peak, as well as others now make a ALL make, model, year, color anti-freeze that is safe to use in ANY vehicle. Being a 98 GM, its more than likely does have the orange Dexcool. DO NOT ADD GREEN to it or youll screw the car and empty your wallet for repair. Buy a bottle of the new stuff and be safe. Autozone even sells the all make , color stuff under there own name for less than 8.00 a gallon.

Lots of people have had intake manifold leaks with Dexcool, especially with the 3.0 family of engines. It apparently can become corrosive to aluminum when air gets in the system. I haven't heard of this with the 3.8, but I have with some 4.3's and V8's.

I've changed my GM's to Prestone and I recommend that to others.

Prestone and Peak will both mix with dexcool without problems. I've only seen the bottles labelled "mix with all coolants" in these brands lately, there may still be some around that doesn't say that.

Bottom line, if the bottle says it's safe to mix with all coolants, it's safe with Dexcool. I prefer to flush the Dexcool out first, just because I don't want it in there.

I wouldn't mix peak or prestone with the orange "european" coolants (Mercedes, bmw, Vw, Audi). I've seen these form a nasty glop when mixed with other stuff, I don't know what's in them.

Rule of thumb is flush the coolant every two years, and flush it before changing coolant types (green to orange or orange to green).  Make sure it is a real flush that completely removes the old stuff.  

GunLvr

Thanks for the good advice.  Will finally be getting around to looking at the vehicle.......it's sitting in my pole barn, waiting for an oil change and a good going over before putting it on the road.  

Will see what they radiator fluid looks like.

Thanks again.

vmax84