Ok... on Friday I pulled into my driveway and shut my car off. When I came back out a couple of minutes later I noticed a pool of brownish slimy stuff under the passenger side. When I popped my hood I saw that it was coming from the coolant bottle. Seems that my radiator boiled the coolant and it flowed back to the bottle.

I checked the thermostat and it is working properly (it's a 160* one), the water pump is working properly (as I can see the water being pumped into the rad when she is running).

I drained my coolant and replaced it. Cleaned my coolant bottle as it was plugged with this brownish slimy crap. Ever since then she is working fine. To my knowledge my car is running fine.

Any ideas on to what could have caused this??

 

Did the recovery bottle just fill and overflow? Obviously you looked for a crack. Slime BAD, I would look into that. Possibly a cap problem, It should pop at 15 PSI. Maybe it's hanging up. At any rate sounds like a good flush is in order.

 

The bottle just filled and overflowed....I think I am going to get a new radiator cap just to be sure. The cap looks like the one that was there when the car was made and the rubber seal on it looks kinda ratty....


I did do a flush and everything seems to be fine now....I haven't did a whole lot of driving since the "incident" but I am going to be checking it more often now......

 

Humm... a crack in what? The rad? The block?

 

I think he was refering to your overflow bottle. On the slime you described it sounds like maybe there was straight water ran in it for a while and then coolant added later on without a flush. So my guess is a rusty water build up with coolant mixed in there. I would definatley flush that system out real good and put some fresh coolant in.

 

No there is no cracks in anything.... coolant bottle, block, heads, etc etc

 

I did mean the recovery bottle. If you are pushing that much coolant out to overflow the bottle you have a problem. Yeah, a cracked seal on the cap will do it. Pressure in the system raises the boiling point of the coolant, loss of pressure will cause the coolant to boil prematurely. Look down from the radiator cap on the engine side of the rad. Very common to develop a crack there that will only open up when it get's hot. You can get flush agents that you put in and then drive the car for a few days. They can work pretty effectively if there is a lot of corrosion in the system. You can run straight water with this procedure. Prestone makes a kit that cracks one of the heater hoses with a fitting suitable for a garden hose. Easy to install, then you can reverse flush the system. Drain all tap water or as much as you can and the fill with the correct mix for the coldest temp you see. It is also a good time to get a look at the freeze plugs, if they are funky replace them. Use distilled water for the final fill with the coolant.