coolant Boiling over - overheating - help!

[fashions]

car is boiling over under hot weather conditions in stalled traffic.

600 miles ago, had radiator flushed, replaced ETCS, new thermostat (saturn parts), changed coolant pressure cap with used one from junk yard. motor was overhauled in car with new rings, head was reconditioned, was running well.

daughter reports it overheated on her, boiled over.

taken to saturn dealer and written up for new water pump, thermostat, ETCS, Radiator Fan - $600+

after rebuild the cooling system was not completely flushed, some coolant still in heater core and some in block, which was both dex and green antifreeze. can this cause a gel problem reducing flow?

will see car tomorrow (150 miles away)

check list for tomorrow.

double check fan circuit - jumper ETCS leads, turn on AC, trade horn / cooling fan relays. have seen a posting of the electric cooling fan failing when it is hot and working when cool.
another candidate to wire up wolfman's cooling circuit/switch?

flush cooling system till clear to remove old antifreeze, refill with dex cool (orange)

check oil level

check hoses / radiator fins for blockage

check auto transmission fluid level- lost some in radiator removal. its time for a transmission flush at some point soon.

we saw this condition last summer and with all the motor work done it has not corrected the condition. i am leaning towards the fan giving out as the problem. was surprise at Saturn not pinpointing the problem will talk with service person on monday to see if he can shed more on the diagnosis.

your thoughts please,
baffled.

[Sky King]

Originally Posted by fashions

double check fan circuit - jumper ETCS leads, turn on AC, trade horn / cooling fan relays. have seen a posting of the electric cooling fan failing when it is hot and working when cool.
another candidate to wire up wolfman's cooling circuit/switch?

.

My first question, considering everything you state has already been done, is when you did what you stated in the quote above, did the fan ever come on?

Regardless of engine/coolant temp, the radiator fan should come on anytime the airconditioner is turned on, PROVIDED the airconditioner is working correctly.

If the airconditioner is working and the fan is not comming on, check for 12 volts at the fan connector OR you can run 12 volts directly to the fan motor from the battery.

If the fan never comes on under any of these conditions, the fan motor is shot.

From your post, you didn't say but I presume it is not overheating/boiling over if she is moving forward at a steady speed above 35 or 40 MPH. If this is the case, I doubt you have any thing wrong with the rest of the cooling system. The fact that you say it is overheating/boiling over when stalled in traffic says it is an AIRFLOW problem. When the car is not moving you have no airflow over the radiator if the fan is not running. When the car is moving, air is forced through the radiator.

My money is on the radiator fan motor. It is easy to replace yourself and not very expensive at most aftermarket parts stores.

[fashions]

Originally Posted by Sky King

My first question, considering everything you state has already been done, is when you did what you stated in the quote above, did the fan ever come on?

yes when breaking in the motor it was operational, i have learned that the ac will turn the fan on, and yes the ac is working well in her car.

Regardless of engine/coolant temp, the radiator fan should come on anytime the airconditioner is turned on, PROVIDED the airconditioner is working correctly.

If the airconditioner is working and the fan is not comming on, check for 12 volts at the fan connector OR you can run 12 volts directly to the fan motor from the battery.

thanks for the tip.

If the fan never comes on under any of these conditions, the fan motor is shot.

From your post, you didn't say but I presume it is not overheating/boiling over if she is moving forward at a steady speed above 35 or 40 MPH. If this is the case, I doubt you have any thing wrong with the rest of the cooling system. The fact that you say it is overheating/boiling over when stalled in traffic says it is an AIRFLOW problem. When the car is not moving you have no airflow over the radiator if the fan is not running. When the car is moving, air is forced through the radiator.

at speed cooling is ok. July 2006, July 2007 both months when its hot here 90's + the car has boiled over. have located the fan motor for $35 - $43 and will pick one up an change it out. am guessing the fan blade will have set screws or such to replace the motor.

My money is on the radiator fan motor. It is easy to replace yourself and not very expensive at most aftermarket parts stores.

Any thoughts on mixing the coolant dex & green causing problems with cooling ? thanks for your promt reply, just what i needed before my trip tomorrow or latter today. your posting on the cooling system was excelent !

[Sky King]

Originally Posted by fashions

Any thoughts on mixing the coolant dex & green causing problems with cooling ? !

You ask this question in the other thread. One coolant was designed to last longer than the other. By mixing the two the one with the shorter design life expectancy will just cause the other to be shorter than it was expected to have. But it will not gel the coolant as you asked and it will not cause any cooling system damage.

[fashions]

Originally Posted by Sky King

You ask this question in the other thread. One coolant was designed to last longer than the other. By mixing the two the one with the shorter design life expectancy will just cause the other to be shorter than it was expected to have. But it will not gel the coolant as you asked and it will not cause any cooling system damage.

thank you that is a relief to know. the green dye over powers the orange and does make for mistaking the dex cool as the proper antifreeze for our '99 sl2. will have to get it flushed out eventually.

[DonP]

To simple an issue probably, but not unheard of for the connector to the fan to have been left disconnected.

[brettkramer]

I agree with SkyKing, regarding most everything, the only other things I would check are the Fuse controlling the fan, make sure you have the right type and I would also change the temp sensor. I had a non-Saturn that operated with two fans, (two fans on one bank of fans) one of the fan motors failed putting additional stress on the other fan and the system, it then proceeded to blow the fan's fuse causing a boiling over so radiator fluid appears to dissapear when actually you are losing fluid through the overflow tube when you are driving. Replacing the fan, the blown fuse and the temp sensor solved my problems. You didn't mention which model Saturn you have, but there was a certain year where Saturn improved its temp sensors, it's a cheap part to replace.

[OU812]

97 SW2

My expansion tank boiled over today but the temperature guage didnt go pass the center mark

[kornphlake]

Originally Posted by fashions

thank you that is a relief to know. the green dye over powers the orange and does make for mistaking the dex cool as the proper antifreeze for our '99 sl2. will have to get it flushed out eventually.

I had a guy at a radiator repair place tell me something quite the opposite.

I had a chevy blazer that the water pump went out on, I didn't have time to replace it so I took it in and had a mechanic replace the pump. A week later I took the car on a long trip and ended up with a leaking radiator, I took it in for a quote (I was away from home without tools, what was I supposed to do) and the guy noticed that the radiator cap had a red dot but the coolant was green, he suggested that I put the wrong color antifreeze in the car. I explained that I'd just had the water pump serviced and the mechanic must have put the wrong color antifreeze in. The old radiator repair guy was suprised that I wasn't upset, he said I should be. Apparently when you mix the two types of anti-freeze an acid forms that destroys radiators, heater cores and eventually engine blocks. A little paranoid at that point I asked if I should switch back to the red stuff, he said that I was better off just flushing the system and using green, he felt like it was less dangerous to have a residue of red antifreeze with a system full of green than to have a little residue of green with a system full of red.

About 6 months later the thermostat died, a few weeks after that the heater core broke, as these had not been the only problems I'd had, I sold the blazer before I had any more problems. It could have been a coincidence or it could have been that I was in fact circulating acid through the engine and cooling system.

[seahawk]

Kornphlake, the Dex Cool alone is probably what ate your cooling system. It has what they call O.A.T. inhibitors in it to control corrosion. O.A.T. stands for Organic Acid Technology which is probably why they don't spell it out for you- because I wouldn't put something with acid in it in my cooling system. fashions, don't worry about mixing the different coolants, they ARE chemically different but they won't react with one another to form an acid, as I said before, the Dex-Cool already contains some acid. I flushed the Dex-Cool out of mine a year ago (40,000 miles) and have never had a problem. Good luck finding the overheating problem and please post back with what you found.

[eRic 02sc2]

Originally Posted by OU812

97 SW2

My expansion tank boiled over today but the temperature guage didnt go pass the center mark

I'd suggest getting a new cap from Saturn. That solved that problem on my 96 SC2. a new cap from my Saturn retailer held the pressure correctly.

[fashions]

thanks for all the thoughtful replys. the fan motor was the weak link in the overheat condition.
when the motor was cold the fan came on. as the temp rised the fan would quit. am guessing the brushes were at the end of life. read another post about this condition prior to servicing the car. the relays , ets, cap were fine. traded out the cooling fan motor only and the car runs at 1/4 - 1/2 temp gauge. no more problems in 95+ weather with the a/c on or off.

this was the problem before the engine overhaul i am sure. now she has a rebuilt motor for the next 200K

[BarnOwl]

Originally Posted by kornphlake

Apparently when you mix the two types of anti-freeze an acid forms that destroys radiators, heater cores and eventually engine blocks.

That might have been true at one time but, if you take a look at the label on any anti-freeze nowadays, you'll see that all of them say dex compatible.