Please help..coolant overflowing from reservoir

[89merk]

I hope this is a faulty radiator cap but heres what happened:

After driving about 15 miles and parking the car i hear water falling after opening the hood i see the reservoir is over flowing but the strangest this was that there was the brown foam coming out along with the water.

heres the video, I know the quality is shit(cell phone cam)please give me your opinions
http://www.youtube.com/watch?v=K5vv1WzTDn4

[87_crown_vic]

looks like somebody used Bars Stop Leak in it instead of actually fixing the problem leak it had. my 87 Grand Marq had no leaks and clean coolant, but when i got it back the guy added Bars to it and it looks the same. i need to flush mine out now and refill with coolant/antifreeze. seems no matter how many times you flush your system, that brown crap is always in there

[Tiggie]

It's probably just rust causing it to be brown, and the foam from some kind of additive. Antifreeze won't foam on it's own. These cars often get neglected in the antifreeze department, causing it to get very rusty in there. After running it a little hard, you can expect the antifreeze to be brown if you haven't changed it since you bought the car.

I'd do a flush and fresh coolant. When I flush, I go get the car warmed up and run it pretty hard. Then I drain the coolant from the radiator. Then I pour in the flush, and pour in some hot water, and drive again. Repeat draining radiator and refilling with water until it drains clear (plan on 5-8 drain/refill cycles). After it runs clear, you can add 100% antifreeze. I think they hold about 14 quarts (about half of which says in the block and heater which will be water by this point), so figure on adding 2 gallons of 100%. You might have to drain a little to get a 50/50+ mix, but it should be pretty close without that.

While it's not likely, it might be a head gasket problem.

[89merk]

thats the thing, i just got the head gasket re-done in september, unless the shop lied to me and fucked me over.
im hoping its a bad cap due to the rust in it.
and is it bad to run 100% antifreeze?

[Tiggie]

and is it bad to run 100% antifreeze?

Yes, if that's all you're running. It's not the best heat conductor. Once you get done with my aboved mentioned flush routine, you'll have roughly 6-8 quarts of 98.5% water in the system. Add 100% antifreeze to that, and you should come out at about a 50/50 mix. Keep track of how much full strength antifreeze you put in it and you can roughly figure out your percentage.

[gadget73]

What he said. There is enough straight water in the block at that point that you can drain the system at the radiator and refill with straight coolant to get a pretty close to 50/50 mix. It may not be exact, but it should be close enough. You live in Florida, so you don't really need to worry about how strong the coolant is. Its mostly there for anti-corrosion, water pump lubricant, and boil-over protection. If it comes out a little weaker than 50/50, you should still be fine. You could probably run as little as 25% antifreeze and be OK, just don't run straight water or the cooling system will rust up badly.

[89merk]

Can i just disconnect the hose from the bottom of the radiator, put a garden hose into the radiator and run it till it comes out clear?

[87_crown_vic]

i run a hose into the radiator and run the car till it comes out clear... make sure it comes out clear and that the thermostat opens up a few times so that the engine gets cleared out also... i would do this in a yard or someplace where the fluid isnt gonna make a mess or animals get in it.

[cld783]

put a garden hose into the radiator and run it till it comes out clear?

yea but use the drain on the radiator instead.. keep running the engine and repeating until it comes out clear

[89merk]

ahh...good thinking, thanks

in the meantime all i did was change my cap and haven't had any problems

[gadget73]

you can do that, but once you drive it around, more crap will come out. You may need to do a few cycles of that before it comes out really clean. Mostly this is because the thermostat is likely going to shut with cold water pouring into the radiator.

[86VickyLX]

I remember when I got my new radiator, well semi new. I needed to test it for leaks, so i just ran water through it, it got up to operating temp, no leaks, I shut it off, opened the radiator cap with a shirt, so I would get backsplash or whatever, and I pulled the upper lower radiator hoses off and bam, clean, and since the thermostat was open, I easily drained everything out of the engine as well. Then I filled it with 50/50 premix from prestone I believe. I started the car, put the heater on high, let it run with the radiator cap off, until the antifreeze started coming out of the top of the radiator. Then I put the cap on, and topped off the reservoir, and gave the engine a few revs and the system was repressurized.