One of my wife's coworkers has a 98 Chevy truck that has been overheating on him. I asked him the basic overheating questions (coolant, thermostat, fans...) and he said the coolant just disappears so I'm thinking HGs. I told him to bring it over and I could have a look and do a compression test. I have changed my diagnosis after seeing this...
(http://img.photobucket.com/albums/v648/Loaded87IROC/2010-12-02082808.jpg)
(http://img.photobucket.com/albums/v648/Loaded87IROC/2010-12-02082209.jpg)
(http://img.photobucket.com/albums/v648/Loaded87IROC/2010-12-02082817.jpg)
I went ahead and did the compression test anyway (150-160 in all cyls) and the oil looked good. I ended up telling him he should probably have the entire cooling system flushed by a shop with the right equipment because I don't think the over the counter stuff will cut it. That dexcool can be some nasty stuff.
Yep. That's exaclty what my S10 looked like after Dexcool worked its magic. I flushed it, replaced the intake gasket, water pump, and thermostat. Green coolant is back in and all's well.
Dexcool is pictured next to the word fail in a dictionary I have here....
Mmm chocolate ice cream.
I had a buddy that brought over his Impala and I found something similar. I was horrified. I didn't know what to tell him because all my cars except my jetta run green goo. I told him a flush at minimum was in order. I read up on Dexcool, and apparently it is pretty good at what it does BUT, you must never let your level get low. Once it gets low, the coating it applies to the metal surfaces starts to break down, thats where the goopy junk comes from.
More than you want to know here:
http://www.motor.com/article.asp?article_ID=816
I would just prefer to run regular old green stuff and flush/fill every couple years.
-Z
And its bound to get low because it eats up gaskets.