'94 Caprice 5.7L Please Help!

[Amen]

I was driving my car last week when I noticed it was starting to overheat.
I got it home as quick as possible and once I turned off the car, all the antifreeze came out from under the hood and there was an enormous amount of smoke coming from under the hood.
The next day I checked the oil and it looked fine, I replaced the thermostat, and I filled the radiator with water and antifreeze.
Now when I turn on the car, it idles very fast and rough, and shuts off when I put it in gear and press the gas.
When I try to turn it back on, it will crank but won't turn over.
The car had no previous issues.
If anyone can give some suggestions, I would greatly appreciate the help.

[CD Smalley]

Sounds like you are headed for a water pump and opti-spark replacement to me.

Sounds like the water pump is leaking and getting coolant into the opti-spark.

[j cAT]

Originally Posted by Amen

I was driving my car last week when I noticed it was starting to overheat.
I got it home as quick as possible and once I turned off the car, all the antifreeze came out from under the hood and there was an enormous amount of smoke coming from under the hood.
The next day I checked the oil and it looked fine, I replaced the thermostat, and I filled the radiator with water and antifreeze.
Now when I turn on the car, it idles very fast and rough, and shuts off when I put it in gear and press the gas.
When I try to turn it back on, it will crank but won't turn over.
The car had no previous issues.
If anyone can give some suggestions, I would greatly appreciate the help.

I agree with the opti getting coolant in it .....that is a major PITA.......

what caused this coolant problem is what you must find out ...could be the water pump, could also be the steam pipe...or another componet ..like cracked radiator tank etc...

what is your coolant condition ? what does the interior metal look like thermostat area etc....

this engine takes 4.25 gallons total of coolant ...draining the radiator you get only maybe half of that out ...

[Amen]

Update:
The things I've done so far are change the oil, the thermostat, and the fuel filter.
I started the car and let it run for a little and there were no leaks anywhere and the water pump looked dry.
When the car starts to shake and seem like it's about to shut off, I hit the gas and it stays on. This is the same when I turn the car off and try to start it again, it gives me a hard time but when I press down hard on the gas, it will kick over and start.
When it idles for about 10-15 minutes, it gets hot and antifreeze/water boils out of the overflow tank.
I looked inside the overflow tank (when it cooled off) and the fluid did look a little dark.
The next thing I'm going to try to do is flush the cooling system and see what happens.
I'm just learning about car engines so I'm going to try to do anything that I can do myself. I need to figure out the source of the overheating.

[j cAT]

with a pressure tester make sure you have no leaks ....your eyes can't see thru the metal ....?

what fan system does this have? the fan clutch type , or the electrical fan[s]..............?.?

did you ever replace the coolant cap ?

what antifreeze are you using ? dexcool ? silicate ?

[Amen]

Everything is stock in the car, the fan system is electrical.
I didn't replace the coolant cap. Are you talking about the plastic cap on top of the overflow tank?
I never touched the anti-freeze, I just checked the level periodically. So I don't know exactly what's in there.
My next step is the radiator/cooling system flush this weekend.
Also, there is white smoke coming out of the tail pipes when I start the car. Does this mean it could be the head gasket? That's what I've heard before...

[inafogg]

a little white smoke on start up is ok.if it continues or gets worse while running
is'nt good(head gasket)

[j cAT]

Originally Posted by Amen

Everything is stock in the car, the fan system is electrical.
I didn't replace the coolant cap. Are you talking about the plastic cap on top of the overflow tank?
I never touched the anti-freeze, I just checked the level periodically. So I don't know exactly what's in there.
My next step is the radiator/cooling system flush this weekend.
Also, there is white smoke coming out of the tail pipes when I start the car. Does this mean it could be the head gasket? That's what I've heard before...

interesting " overflow tank " the cap should state what coolant to use and the pressure should be listed as 15psi...what does the cap say ?

before you do any coolant replacement you MUST KNOW what coolant is in it ! there are 3 types commonly available ...silicate, compatible, then theres dexcool ...which must only be used with dexcool GM LOGO approved on the container ...this fluid will be red/pink ....yellow is the other stuff,,,,you don't mix coolant or you will have a plugged up coolant system with black goo growing in it ....

yes white smoke means you head gasket with the overheating is defective ...you should go to a recommended repair shop and have then pressure test the system to check this out ....

head gaskets normally go when the coolant system is not correctly maintained ...this causes corrosion/overheating and this and many other coolant system failures ....

with the overheating the fan should come on around 235 deg F

[Amen]

I did the radiator flush over the weekend. The fluid was pretty dark and thick.
I made sure everything was out of there and then filled it with the proper anti-freeze/water mix.
Both electric cooling fans did come on and were working fine.
I let the car run for a little and it didn't overheat.
A lot of white smoke comes out the tailpipes when I first turn the car on but then it dies down.

The problem now is that the car won't stay on. I have to push the gas down sometimes when I crank it.
And when I let it warm up and then try to shift the car to drive, it shuts off and won't turn back on.
It'll keep cranking but won't kick over. This was never an issue with the car until it overheated that first time.
Do you think something could have gotten ruined when I ran it hot? Maybe the spark plug wires or some kind of fuel lines?

[j cAT]

Originally Posted by Amen

I did the radiator flush over the weekend. The fluid was pretty dark and thick.
I made sure everything was out of there and then filled it with the proper anti-freeze/water mix.
Both electric cooling fans did come on and were working fine.
I let the car run for a little and it didn't overheat.
A lot of white smoke comes out the tailpipes when I first turn the car on but then it dies down.

The problem now is that the car won't stay on. I have to push the gas down sometimes when I crank it.
And when I let it warm up and then try to shift the car to drive, it shuts off and won't turn back on.
It'll keep cranking but won't kick over. This was never an issue with the car until it overheated that first time.
Do you think something could have gotten ruined when I ran it hot? Maybe the spark plug wires or some kind of fuel lines?

the reason the coolant looked that way is because someone mixed dexcool with silicate coolant ...it don't take much when these different coolants get together ..

your problem on engine stalling and running bad is with your description of what happened when it overheated is the opti distributor got coolant in it ////////or you cracked a spark plug when the coolant washed over the engine ....I would replace plugs with the ac delco ones then using a meter measure all plug wire resistance ///they should read about the same the longer the wire ,,, the higher the resiistance slightly ...if after this it still is bad then the opti is highly suspect ..good luck...

[wormfriskie]

Try replacing your coolant temperature sensor on the front of the water pump. It is part of the engine managment controls, and if it doesn't function properly the car will start rough. It costs about 15 bucks at your local auto parts store, and is normally stocked. I had the same problem, minus the overheating, but when I replaced that the car started fine.

[Amen]

I replaced the coolant temperature sensor and the rough starts and idles went away!
BUT THE OVERHEATING IS BACK!!!

So far I've flushed the cooling system several times, replaced the thermostat, replaced the fuel filter, and replaced the coolant temp sensor. I also took off the coolant reservoir and the upper and lower hoses and cleaned them all thoroughly.
When the car starts to overheat, smoke will come out of the coolant reservoir cap first and then the coolant will later boil out of that cap.
I'm thinking radiator or water pump but not sure how to tell which one it is. I want to be sure.

[inafogg]

how many miles i didnt see it in your post.like you stated possible water/p rad
i agree but i'm not to sure thats going to fix EVERYTHING.if i were doing this
i'd do a compression & a leak down test.just to make sure we didnt blow a
head gasket.Good Luck Mike

[j cAT]

Originally Posted by Amen

I replaced the coolant temperature sensor and the rough starts and idles went away!
BUT THE OVERHEATING IS BACK!!!

So far I've flushed the cooling system several times, replaced the thermostat, replaced the fuel filter, and replaced the coolant temp sensor. I also took off the coolant reservoir and the upper and lower hoses and cleaned them all thoroughly.
When the car starts to overheat, smoke will come out of the coolant reservoir cap first and then the coolant will later boil out of that cap.
I'm thinking radiator or water pump but not sure how to tell which one it is. I want to be sure.

so what product did you use when you flushed the coolant system ? did you remove the knock sensors to drain the engine when flushing ...

you must use a 15 min acid flush not the detergent type of flush..