cooling problem

[interceptor7]

Ok, here's the issue. Temps started getting higher as I accelerated. They got as high as the "N", between the last 2 white marks. Stopped at a gas station, and the radiator was almost bone dry. The reservoir was still full, though. Cap is new (16lb)and was still holding pressure (pressure-release type; when I released the pressure, some coolant and steam squirted out). Radiator is aluminum 3-core, thermostat is 180 deg, pump is an Edelbrock unit. Rad, therm, and pump are about 4-5 years old.

Anyways, filled it back up, ran the engine for a while and didnt find any leaks. Temps went back down to the "L".
Anyone got any idea on what's going on?

 

[bullitstang1313]

How long did you run it after you added water to it? Did you let it get back to operating temperature? Its possible that you are burning the coolant. Did you check to see if any smoke was coming out the exhaust? What kind of mods do you have done? Supercharged/Turbocharged?

 

[gcwh02]

change the t stat. Its a cheap, quick change and might be your prob.
or you could have a clogged rad.

 

[GTOreturns]

clogged cats can make it over heat during acceleration.

 

[QUIKSVT]

I'm having the same issue as you... I can't keep head gaskets sealed up right now, I'm on the third set in 2 weeks. They all blow between the bore and the coolant passages, which then pressurizes the cooling system (especially under throttle) and pumps the coolant out of the radiator and into the overflow...

My block may be distorted or something, I'm about to just yank the motor.... If I were you, I would run compression on all holes and see if maybe you popped a HG...

 

[Maryland Stang]

You're absolutely using the wrong cap. A "pressure release" cap is only designed to allow coolant to flow in one direction... Out of the radiator. You should be using a coolant recovery cap (the one without a lever).

As your engine builds pressure it will push some coolant out of the radiator. With a pressure release cap the coolant only flows out of the radiator and as the car cools while it sits the cap won't allow coolant to be pulled back into the radiator from the coolant recovery tank. Do this enough times and the radiator will be dry.

The same process occurs with a coolant recovery cap but as the car cools the cap is designed to allow coolant to flow back into the radiator.

When my car was using coolant due to a bad timing chain housing gasket I always put additional coolant in the tank and almost never opened the radiator. I'd drive it a little while and look at the tank and the radiator would suck it dry. Add more till it doesn't take anymore.

The first thing I'd do is try the correct cap and see what the car does.

You didn't say how long it had been since you checked the coolant level. If it has been months on end then it's no wonder there wasn't any coolant in the car.

 

[interceptor7]

You're absolutely using the wrong cap. A "pressure release" cap is only designed to allow coolant to flow in one direction... Out of the radiator. You should be using a coolant recovery cap (the one without a lever).

Thats a new one on me! If it's true (and I'm not doubting you), then everything else falls in place, since I hadnt checked the Rad level since I changed the cap. I did used to check the reservoir level, but then again, there was no reason for it to be low if the system wasnt drawing from it.

Thanks, I'll try that first, since is the least expensive/labor intensive fix.

BTW, I always thought the lever caps were just like the recovery caps, except they allowed you to release pressure before you opened it hot.