my cobra runs too hot?

[94cobra#519]

people i dont get it. i know its not the guage and i know its not the thermostat. the fan kicks on and the radiator seems to be flowing good. what can it be? my car is running very hot. so hot that the puke tank is puking lol. the overflow taking is overflowing like crazy. but the weird thing is its not always. last night i dorve it for maybe 10 miles and it got hotter and hotter until it was starting to touch the Red line on the [normal] guage. i cant figure it out. i just replaced the thermo with a 180* from a 192* AND ITS THE EXACT SAME. the fan kicks on high but maybe not low? anyway any other ideas?

 

[Chythar]

Possibly you have a blown head gasket. When the engine is cold, pop the radiator cap and smell the coolant in the fill neck. If you smell exhaust, a head gasket is letting exhaust into the coolant.

You also might not be holding pressure in your coolant system. If the system won't hold 16psi, the temp gauge will rise faster than it should. You might want to check all your hose clamps and make sure they're all tight.

Finally, if you've had the radiator for several years it's possible the radiator might have corrosion built up so it's not dissipating heat like it used to.

 

[94cobra#519]

hmmm maybe yeah.

 

[94cobra#519]

my head gaskets are fine.

 

[revhead347]

Sounds like the tell tale signs of a blown head gasket to me. How did you come to the conclusion that the gaskets are ok?

Kurt

 

[Bullitt95]

people i dont get it. i know its not the guage and i know its not the thermostat. the fan kicks on and the radiator seems to be flowing good. what can it be? my car is running very hot. so hot that the puke tank is puking lol. the overflow taking is overflowing like crazy. but the weird thing is its not always. last night i dorve it for maybe 10 miles and it got hotter and hotter until it was starting to touch the Red line on the [normal] guage. i cant figure it out.

Your cooling system has to be overpressurizing if it can overcome a 16psi radiator cap and the only possible cause is a blown gead gasket. You could try a new 16psi cap but I doubt it'll help.
I suggest you check the oil for any water contamination (chocolate milkshake appearance) and pull the plugs. If one or more looks much cleaner than the rest or has a brown residue, you've pinpointed the head gasket leak.

 

[revhead347]

The head gasket rarely blows from water to oil. Generally there will be no water contamination in the oil when you blow a head gasket.

Kurt

 

[icemetalstang]

I would go to the local autoparts store and purchase a mechanical temp guage. Run it in the car for about a week. There about 15-20 bucks. Also when the car reaches operating tempature reach down (Be careful hot) feel the bottom of the radiator. If it is cold and the top of the radiator is hot you my friend need a radiator.

 

[94cobra#519]

well guys i have concluded it is my fan switch. the fan is not kicking on early enough and only stays on for about 20 seconds. so i got the idea of running the ac constantly to override the fan switch and keep the fan running. in most cases the ac would cause the car to run hotter especially 110* fresno weather. anyway so i have been running the ac constantly and it has been running much cooler. it has been running at (a) in the [normal] guage. as opposed to l or the bracket. anyways so i have decided to get a fan control switch from jegs or summit. and i need to know what is the best and best for the money. or what you guys recommend.

 

[Chythar]

That's still incredibly hot, as far as out inaccurate factory gauge goes. If the gauge (or sensor) were working reasonably "correct", temps should not get much higher than "M" before the fan kicks in. Do you have a code reader that can do more than read error codes? My Autoxray lets me see sensor input like throttle position and the coolant temperature the computer sees. It's possible that the ECT is giving the computer the wrong temperature reading, and the computer is causing the engine to heat up.

 

[HISSIN50]

Is your fan running on high or low speed with the AC on? It should be high but it might only be low.

Do you have the circuit breaker retrofit installed on your fan connector?

If you want, ohm out your ECT when the engine is hot and post the resistance value you get (that is, if you can't view PIDs like Matt talked about).