I have a 1.9l sohc 97 Saturn sl1 that i just got. It randomly overheats. it has a new water pump no thermostat, replaced the fill bottle pressure cap, fans come on when they are suppose to. Once the engine warms up the upper and lower pipes are hard and hot with water coming out of the new pressure cap, the heater also stopped blowing hot air. There is no oil in the water and no water in the oil, also no water in the exhaust.

 

are you using plain water?

 

For the time being yes I am.It was doing the same thing when i first got the car it had a 50/50 mix and a thermostat in it at that time. since then i have replaced the water pump and thermostat but only tested them using the plain water.

 

Water boils at 212 degrees F. Even by testing with just plain water, it's going to run hot. Have you done a flush of the radiator, heater core and block? If not, then that should be your next step. Check all of your hoses and make sure you don't have one that's collapsed. That includes heater hoses.

 

You may still have a blown head gasket. It can blow exhaust gasses into the coolant but not allow the coolant to be drawn back into the engine.

But the first thing I would check it the bleed hose. Its a small diameter hose that goes behind the engine and connects the coolant passage at the back of the block to the reservoir tank. Make sure that is clear or air can get trapped in the block and will act like a blown head gasket.

You need at least a little antifreeze in your water. Water has a high surface tension that interferes with the transfer of heat between the metal and the water. a little antifreeze, even just a quart will break the surface tension and increase the efficiency of the heat transfer.

You should also keep a thermostat in your car, it won't run right without one.

 

Am with others on the "Anti-Plain water" routine. Todays engine's with aluminum heads and cast iron blocks due some really awful electrolysis action that causes deposits that end up in the radiator to plug it and other things. This is a not good deal along with the way the heat up and run at very high operating temperatures. Straight water is just a quick way to screw things up if you are running it for any length of time and if it is over heating with water, the fix is to run anti-freeze.
Hint, Premixed anti-freeze is 50% water, the stuff you get free out of the faucet For the same price get full strength which is 100% anti-freeze and mix it your self.

 

Hopefully I am asking this question in the correct place....
I've got a 1997 Saturn SL2 and have been having issues with it getting hot (temperature gauge at 3/4 as well as the low coolant/high temp indicator on dash lights). I have replaced both hoses, thermostat, and radiator. My question is; after replacing all of the aforementioned parts, I went to add coolant and could only get about 1/2 gallon into reservoir. Initially when I installed thermostat (last week) I was able to get about 1.5 gallons into system. I have let it run in hopes of thermostat opening and allowing more coolant into system, as well as parking on incline in hopes of "burping" system...no luck. What am I missing? Why can't I add more coolant? After letting it run for about 15 minutes I drove around SMALL block in neighborhood...after about 200 yards, the temp gauge went to ALMOST red...please help!

 

Temp gauge running at three quarters is not in an of itself an issue as long as the fan under the hood turns on to bring it back to operating temperature.

That cooling fan should turn on at somewhere around the 3/4 mark on the gauge. Does the fan turn on at that point? All of this with a properly filled and burped system?

Did you drain the block when you drained the system to replace the components? The screw is in the bottom of the block. Hex head I believe.
You probably have a huge air pocket in the system, one that is too big to displace easily.

Also, does your fan under the hood turn on when you turn on the air conditioning and the compressor clutch kicks in? If not, either your fan motor, fan motor relay or ects or associated wiring may be at issue.

The coolant temperature at which the fan turns on is controlled by the reading from the ects. So if that is defective or producing an incorrect result, usually the fan never turns on in the vehicle truly overheats.

If the fan is not come on when you engage the AC and your AC system is charged and functional, see above.

The temp idiot lights on the dash on an S car are usually triggered by the coolant level being slightly low. Fill to the center seam of the overflow tank, then go a little bit more. For whatever reason, the pressure sensors at the bottom of the tank seem to become much more sensitive as the car ages.

Might you have not fully drained the system the second time, thus leading to you requiring less to put in?

Make sure you remember to put the block drain plug black in before you start to fill. Been there done that.

If you absolutely cannot dislodge the air bubble, get a cork with sloped sides that fits the reservoir opening. Drill out a center hole for a fitting period connect up some tubing can't use a hand pump to apply no more than a few PSI of pressure to the system with both the block drain plug and the radiator petcock open. That should push all the air and fluid out of the system.

Park the vehicle on level ground. Jack up the vehicle behind the right front tire so that the reservoir is significantly higher than the rest of the engine. Take your time pouring the coolant mix into the reservoir . You will hear it almost constantly burping period as it sales it will take longer to burp itself.

Bring the vehicle back down onto the ground
Let it burp some more, add some more 50/50, and get it just above the seam level in the overflow tank.

Speculation of a southern blockage in the system at this point is not terribly helpful until we know exactly how much fluid you add in after completely draining and pushing the air out.

I did the above last week minus the pressure displacement.

Please respond regarding the fan under the hood so we can sort that out or rule it out