So I was driving home...

[Therian]

and I noticed my temp gauge was going up, fast.

luckily I only had about 500 yards until my place. I parked it, promptly shut off the engine and opened the hood. It took a bit of time, but coolant started flowing steadily out of the overflow bottle and onto the road. I could also hear hissing from the valve covers, and see coolant bubbling out between the gasket and the VC.

I had a tstat done about 3 years ago when a similar problem happened. Could it be stuck open? Where do I go from here.

Looks like this is the last straw and I'll be putting her away until next spring when I decide what to do next.

 

[BlackVert]

i would think stuck closed might cause it to overheat, but not stuck open

 

[Therian]

i would think stuck closed might cause it to overheat, but not stuck open

I get confused

 

[parchisi]

run a car a little. feel the top hose, if its cool even after the car warms up then your t-stat is stuck closed. Coolant coming out of your valve cover.....??? That doesn't sound good...

 

[Therian]

Coolant coming out of your valve cover.....??? That doesn't sound good...

that's what I thought. I could hear it sizzling, looked, and then saw the bubbling. I'll check the rad hose. thanks.

 

[SQUEEZE&STROKE]

How is the coolant level?

 

[davins130]

i've never heard of coolant comming out of the valve cover....unless you have a coolant oil mix running through everything and comming out of your valve cover...but that would be bad

 

[Zero_chance]

Could be blown head gasket. Only reason Id think youd have coolant flowing from around the head and valve cover.

 

[cbarr300]

I'd check compression or do a coolant system pressure test.

If you have a blown headgasket it could be pressurizing the coolant system (resulting in coolant overflowing) and causing you to overheat because the radiator just can't dissipate the heat from the combustion gas.

if the coolant really is flowing from the valvecover....then I'd have to put my money on a blown headgasket.

btw, a car can still run well with a blown headgasket....so just because the car runs well isn't a clear indicator that a headgasket isn't the problem

good luck

 

[davins130]

+1 on the coolant pressure test....cheapest and easiest way to go if coolant is comming out anywhere, you will find the leak more than likely....if you dont have a pressure tester, you should be able to talk someone at a shop into pressure testing your car for free (takes all of 30 seconds and no tools)

 

[go-stang5.0]

Yea compression test, coolant pressure test, and also check your oil dipstick. If oil is frothy just after running it could indicate coolant in the oil. Or you may just outright see coonant on the dipstick.

 

[go-stang5.0]

Oh sorry...did it overheat...could also be a warped/cracked cylinder head. Not trying to scare you or anything but tellin it like it is.

 

[Bullitt95]

and I noticed my temp gauge was going up, fast.

luckily I only had about 500 yards until my place. I parked it, promptly shut off the engine and opened the hood. It took a bit of time, but coolant started flowing steadily out of the overflow bottle and onto the road. I could also hear hissing from the valve covers, and see coolant bubbling out between the gasket and the VC.

I had a tstat done about 3 years ago when a similar problem happened. Could it be stuck open? Where do I go from here.

This sounds to me like you're getting overpressurization of the coolant inside the engine itself, and there can only be two reasons for that:

Thermostat sticking closed
Blown head gasket (cracked head less likely but possible)

The thermostat obviously did open eventually because the coolant started flowing out of the overflow reservoir. The simplest thing to do would be to replace the thermostat. Test the new one first in a pan of boiling water before you install it because even new ones can be faulty (I had a new Motorcraft 192* thermostat that wouldn't open so that's how I know). I went for a Mr. Gasket 180 degree unit.

 

[Therian]

will try thermostat.

gut is telling me HG since I had the thermostat done about 4k miles ago.