I've had my car about a year and a half now, and soon after I bought it I replaced the radiator. The coolant (green) at the time was clear, no issues.

About a year ago, the opti got drenched and I needed to replace it. At that time I noticed some brown crud in my coolant, floating at the top. I'm afraid it might be oil, it's slimy to the touch and smells a bit like oil.

I replaced the opti, refilled the system and then had some other issues that caused me to leave it sit for 9 months until I could get back to it and fix it. When I got it running again, there was more of that brown goo in the radiator, and it took a couple dips into the tank with a paper towel to clear the majority of it out (it stuck to the towel).

Well, I was worried about it but did not want to leave it again (I moved to GA and had left the car in PA). So I figured I would drive it as far as I could and if something major happened, tow it the rest of the way.

Well, I made it all the way to Knoxville, and my father-in-law wanted to see it and it had returned to the point where we had to dip rags in the radiator again 2 or three times to clear the majority of it out.

Then I drove it the rest of the way to Atlanta. Now when I check, it is still there, but not as bad. Coolant level was a little low, but we've been doing some messing with it and never really bleeding it properly.

Car never gets over 180 degrees while rolling, when sitting it never gets over 210 or so.

Here's a pic of what it currently looks like:



Think it's oil? I just drove it 800 miles without a hiccup. Oil looks fine (black, but fine). I want to get the system flushed properly and a pressure test done, but I'm trying to get some ideas before then.

 

might be rust? i thought we are supposed to use the orange coolant.

 

wouldn't hurt do to a chemical flush and refill with green antifreeze. has the system ever had dexcool in it? 97 gm put it in all of their vehicles. could be "sludge" the mix creates.

 

biggest problem with Dexcool is it doesn't like to be mixed with regular green coolant - that's when you get the "sludge"

 

Once upon a time, yes, I guess. But I bought the car with high mileage, and when I got it the coolant was green.

 

im just going on what i have heard, if there is ANY dex in there when the green stuff goes in, it will create sludge and/or type of mixture like oil & water. shops overlook the overflow tank in our cars because its doesn't circulate with the system.

 

Have you ever TOTALLY removed and replaced the coolant, and flushed the system? Sounds like all you did was reuse the old coolant when you replaced the radiator, and refill what leaked out. The green coolant needs to be replaced every couple years. It also helps to add a bit of extra anti-rust when you replace it. If the coolant is as old as it appears to be, the results are expected.

 

I wouldn't be as concerned if it hadn't been so BAD at one point. The picture is after clearing off the surface, at one point it appeared like the radiator was full, the since the whole surface was covered in it.

I'll get it flushed. I'd do it myself, but I'm stuck in an apartment and haven't exactly seen a hose laying around.

Unfortunately the first 200k were done by someone besides myself, so I have no idea what was done when.