Contour Enthusiasts Group Archives Forums Modifications Zetec Maintenance Bubbling/Boiling

I posted this topic on Troubleshooting last week and didn't get enough ideas. I have a problem with my coolant/tank. This happens frequently. I'll drive my car for a while. When I turn it off and open the hood I will see that the coolant inside the coolant tank is bubbling/boiling. Steam comes out of it as well. Also sometimes I can hear a high pitched whistling coming from the tank. I've replaced the serpentine belt,tensioners, fuel pump at 54k and the water pump at 56k. The car runs just fine. The temp gauge is at normal reading. It usually reads on the exact spot. Could the coolant mixture be wrong? i doubt that though. I replaced the filler cap and that didn't help. I heard from my last other post about a thermostat being stuck or a bad head gasket, but I have no idea what could be causing this. I am getting worried about it. I need to fix this problem before it gets worse. Any ideas? Help.
Zetec ATX 56k.

After doing a search I am fearing a blown head gasket, but I don't know. Any other ideas?

It sounds like it is a headgasket.
I've had problems with the ZX1 in my kit car where the cooling system is ok when driving around normally but when I'm on the track the coolant is pumped out of the overflow.
Changing waterpump, thermostat and radiator cap did nothing.
I discovered that #2 spark plug was hard to remove, and when I looked down the plug hole and the engine was could, there was fluid on the piston. For me, the leak is compression stroke air from cyl 2 getting into the coolant when I'm playing at high sustained rpm, then coolant leaking into cyl 2 when the coolant system pressure is up and the engine is not running.
I changed the gasket and the head measured so-so with a straight edge but the head was warped enough that it needed a shave.
I would recommend that you shave the head as well as change the headgasket.

If you know that the water pump is good then it's bad news i'm afraid.
m

Have you done a flush and fill of the system? Start there and add some Redline Water Wetter when refilling. If you had a blown head gasket then you most likely would start seeing that temp gauge float higher. That is unless your gauge or more likely the temp sensor is malfunctioning. I think that you can check for a head gasket leak by testing the compression. Someone else may want to way in on this. Your car seems to have really low miles for needing a new head gasket.

I also heard about replacing the radiator cap.Don't know if that would help. So how do you do a full coolant flush? I'd rather not take it to a shop to do it. To add something: The A/C is still working and the coolant in the tank is slowly dropping.

The first thing that you should do is buy a Haynes manual for our cars. There will be detailed instructions on how to drain and fill the radiator. Honestly for about 50 bucks or less someone can do it for you. I thought you had mentioned you already replaced the cap on the plastic tank. If not do that first.

I know this is extremely basic, but make sure you're not overfilling the coolant level. It's a duh issue but could be easily overlooked just becuase of that...

had the same problem on my old acclaim........had to get the head repaired......