AVTekk

Ok heres the problem. The ECM thinks the engine is running hot, altho its not. My guage would read about 140, and it will slowly climb up (within maybe 30 sec) until the 240-250 range where it will turn the check guages light on. The fans come on as well. Then, as if someone hit a switch, it will shoot back down to the actual temp it was running at and the fans will shut off. I thought this may have been a bad coolant temp sensor or soemthing, until today, where it started dumping coolant out of the tank. Will the engine running you can sit and watch the resevoir tank fill up with coolant and overflow and the guage run up to over 200..

Now the radiator is ICE cold when its doing this, cold to the touch, like its not even running. Engine is slightly warm to the touch. I know the engine isn't really running that hot because the oil pressure is still high and I have no heat. I live in NJ so its about 20-30 degrees here now. It used to do this once in a blue moon, but since yesturday, it does it constantly. Now I don't even want to drive it because its spitting coolant everywhere. Please help this is all I got to drive!!

:cuss

UDLUV12

If I were you, I'd replace the thermostat.
It could be that you need to purge your system. Have you tried doing that?

AVTekk

I thought about the thermastat, thats going to be my first step.

Are there any specific steps to purging the system? I thought it was that too, maybe the sensor was reading an air pocket..Let me know, thanks.

AVTekk

Anyone? Steps for proper purge? Any other ideas?? Please, this is all I got!! :\

VQT88Vette

After replacing the thermostat. The easy way is to drain the coolant by the drain valve, close valve hand tight, fill radiator with distilled water, start the car let is warm up to operating temp. Stop the engine, drain the coolant, do this about 3 or 4 time. The fourth or fifth times use 50/60 distilled water and coolant of your choice, drain one more time then use 50/50 coolant to fill up the radiator and the resevoir. Check the reservoir for a few days until the system burb itself. Also, check the tightness of the drain valve, you need to tight the drain valve with a plier. If the valve is not tight enough coolant will escape from there. Need to look under the front of the car to see any colant spilled out from the vale or not since you are filling up the reservoir thinking the system is burbing:). This way you pretty much know that you have at least 50/50 or less solution in the system. You don't have to get more than 50/50. It is too cold to do this out side. Do you have a heated garage? Beside that don't drive until the weather get warmer to do this. You may want to have tha front wheel on ramps when draining because it is very difficult to loosen and tighten the drain valve with all four wheels on the ground.

Good luck

AVTekk

Ok thanks for the steps. By the way, this LT4 is in my S-10 so I can reach things pretty easy. Also I didn't mean to make it sound like Im filling the resevoir up or anything. With the engine running I can sit and watch the resevoir fill up with coolant then overflow onto the ground..That combined with the faulty temperature guage..I dunno..maybe blown head gasket??

93 ragtop

Do you have the hoses hooked up correctly. The LT1-4 engines are reverse cooled. The coolant enters through the thermostat and out the bottom. I thought I would mention this since you said it is in a S-10.

AVTekk

Oh ya, theyre hooked up alright. This has been in my s10 since 2000 with not really any problems. The water pump went once during the summer, but besides that everything has been alright until now..

his touch

If your system is low on coolant, you will not have any heating. The radiator will also be cold. The temp reads hot because it is boiling the coolant in the block.

Ron

CorvetteZ51Racer

The only way you can pump water out of the radiator that fast is if you're pressurizing the coolant system significantly. That can only happen with a blown head gasket or a cracked head. It sure seems to me like you're getting combustion pressure into the cooling system.

Out of curiosity, is there any steam coming out the tail pipe?

AVTekk

Thats what Im thinking, but I hope its not the case..I still havent looked at it yet..As for the steam or white smoke, I didnt notice any more than normal..