'99 Engine oil in the coolant: PLEASE read...
 

Yesterday I parked in my driveway after coming home to see nasty, boiling coolant+oil in the antifreeze overflow reservoir. When I say boiling, I mean profusely steaming from the bottle, spitting out over the battery and radiator.

The following morning, my stepdad and I took off the hoses connecting the radiator to the engine to find them clogged with the nasty (what looks like tan mud) oil. We tried to flush it out with water, and it seems like the circulation is clogged with the crap and won't let any liquid through. *Shockingly* there was no more oil in the engine via dipstick. We spent a good hour trying to purge the engine of the mixture...most of it flushed out, but there is still an amount in the system. We tried heating up the engine to get the thermometer to kick on and circulate water and get the rad fans going, but with no success.

So now I am left with more than one problem. The rad fans are not kicking on, and oil is leaking into my coolant. Could someone explain what makes the electric fans turn on when the car is running (at what point?)? Has anybody seen this happen before? With a bit of web searching I found some information on blown head gaskets and porous blocks, but I am not sure how the specifics on these break down. All I know is that I have a big problem here.

Some more information:

130k Miles, automatic, been driving it for a little over a year now. I now remember hearing the gurgling sound of the liquid a few days ago, but didn't think anything of it. Before perhaps 4 days ago, this has NEVER been an issue (which makes me hope for a bad head gasket).

Any help, opinion, or information would be GREATLY appreciated.

Thanks,
-Aaron

Yes, that's a problem & you seem to be aware of how serious... I guess a blown headgasket is more probable.

About the fans, in 1999 there's ONE fan switch, mounted in the thermostat housing. It's setpoint SHOULD be somewhat higher than normal operating temperature, so I guess the gauge would climb just above 1/2 before the fans switch on.

Beginning 1998, there's no longer a 2nd fan switch, and the fans won't run after you turn off the engine.

I am hoping for the blown Headgasket, I guess there's not much to do except have a mechanic look at it, or try to get to it myself. Thanks for the info on the fans. Cheers.

It's tough to tell from here. Most tests (like pressurizing the cooling system) can give the same result whether the leak is located at the headgasket vs block porosity. I'm not sure how you can be sure without dismantling the engine.