Black coolant / PCM location

[mounddog]

Hi - two questions:
My coolant turns black/very dirty - if i flush it out and change coolant, about 3 monthes later it will get dirty/blackish. I thought it was oil at first, but my mechanic friend said it would be like a milkshake since oil/water dont mix. Any help appreciated.

Also - where is the PCM located on a 1992 Buick Park Avenue? Is the PCM called by any other name? And if anyone has a guess to how much they are - thanks

[ks0309]

pcm /ecm is located under dash ,behind glove compartment it is slide up in place ,held there by a nut and clamp, it has three plugs on it one green and two black,all on same side of box.box is about 8x10x2

[ks0309]

pcm /ecm is located under dash ,behind glove compartment it is slide up in place ,held there by a nut and clamp, it has three plugs on it one green and two black,all on same side of box.box is about 8x10x2 about 85.00 in store 40.00 in bone yard

[Fireflynj]

Originally Posted by mounddog

My coolant turns black/very dirty - if i flush it out and change coolant, about 3 monthes later it will get dirty/blackish. I thought it was oil at first, but my mechanic friend said it would be like a milkshake since oil/water dont mix. Any help appreciated.

I had the exact same thing happening with my 1992 Caddilac SedanDeville.
it is not oil, I kept some in a jug and it never separated like water/oil does.
I replace it with a new radiator, I thought that fixed it but then it happened again, then someone told me to try the new 5yr red/orange anti-freeze that it was safe for all aluminum engine blocks. (or the volkswagon anti-freeze)
never found results of that since i stop driving car due to other problems.