over heating

[sleeper95]

hey guys my 95 mustang started to over heat while i was driving so i stopped and looked it there was coolant all over my engine and resevoir was empty. this happend before but i just filed it back up end it doesnt happen agian. i dont know why it does this i really need some help to know how to fix it and if it is common.

 

[yukisho]

Check your hoses and the clamps on them. If they are fine check the seal on your thermo and your water pump.

 

[sleeper95]

yeah but i look inside my engine and it looked as if it came ut of my coolant resevoir cap but this time it draned my radiator too

Check your hoses and the clamps on them. If they are fine check the seal on your thermo and your water pump.

 

[yukisho]

Check all your hose's. Check the radiator as well for cracks. Jack the car up and get under it. Clean it all off and check the reservoir too.

 

[Chythar]

What you had happen is called a boil-over. Your engine may not have actually overheated, you may just have a problem in the coolant system. In a boil-over, the reservoir cap is where the pressure is relieved - the expanding and hot coolant needs somewhere to go. Basically, the coolant system did its job in keeping your engine or your radiator from going BOOM from the extra pressure.

There are several things that could cause a boil-over. The simplest is a coolant system that isn't sealed properly. Yukisho's suggestion is dead on for that.

Physics 101: coolant under pressure holds more heat per degree of temperature than coolant not under pressure. Essentially, your engine will overheat faster if you leave the radiator cap off - the coolant will pour out of the cap long before the engine is in any danger.

With the system under pressure, the coolant can take more heat away from the engine and dump it out through the radiator. If your hose clamps aren't tight enough they may leak or simply not let the system maintain the appropriate pressure to operate right.

As Yukisho said, check all your hoses for cracks and any signs that they are leaking. Also, tighten your hose clamps. They should be tight enough that you can see the hose clamp squeeze the hose. the best way to test this is with a coolant pressure tester, you may be able to rent one from your local auto parts store. The Mustang coolant system takes 16psi.

Your radiator cap may also be bad - it's intended to hold 16psi. Any higher, and it opens to let coolant expand into the overflow. If it lets off too soon, the coolant will overflow out of the overflow tank.

Report back after you've tried these things, and we'll troubleshoot some more.

 

[WhiteCobra95]

I agree with Chythar. If you're boiling over like that, either the stat isn't opening (air buble, bad stat, ...) or the system isn't holding pressure (leak somewhere). See if you can rent a coolant system pressure tester from a local parts store. These can pressurize your coolant system to operating pressure wile the engine is off (I'm not sure what it is from a Mustang, 14 psi?), then you can check to see if it hold pressure, or if you can see/hear a leak somewhere. Leaks could come from a loose or cracked hose, a bad stat housing gasket, cracked radiator, or worst case a bad head gasket. The really small leaks are the most difficult to find since they don't puke coolant like the big leaks do, and some of them only open up when the engine is warm. I hope it's something simple and easy to find.

Also, make sure your electric fans are running properly. This shouldn't be an issue when driving down the road, but it could be during an extended idle or long up hill driving with the A/C on.