Another OverHeating Saturn

Hello,

I am very frustrated with my 99 SL1.
This car has been fine for since I bought it. It currently has about 76,000 miles on it. Recently it started leaking coolant. No changes in temp or performance. Turns out it was the water pump, so I had that changed out. The mechanic said that the fan motor was dead to. Well, didn't have the cash for that right then. That same day I had the pump changed; it was redlining on the temp gauge if I drove it a few blocks. Naturally this freaked me out. I took it back to the shop and got a mouth full of garbage from this guy. He was blaming the fan. OK buddy, it wasn't doing this very morning before you guys touched it. He wouldn't do a damn thing about it, nor give me a better explanation.
The next day I took it to a completely different outfit just to have it looked at and to see what they would say. Dead fan was there answer. OK, so I had them change out the motor. Cool, this should be it right? NOT! Before I even get home the bastard is hot! ARGH! but the fan is kicking on. OK what's next? That weekend I change out the thermostat, flush coolant system and fill with the right stuff. The guys that did the pump put in the green stuff and I was told that's bad for this car. OK, so take her out for a spin, since it was looking pretty good. NOPE! Nothing has changed. I drive a few block an it goes RED! I've read around it could be those coolant temp sensors? Any ideas?? Any more suggestions would be nice... Oh ya, the coolant before and after the flushing looked fine, neither milky nor brown and nothing in it like particles. HELP!!!

oh one more thing, don't know what this implies but, when the temp gauge is slightly up and key is engage without starting the motor, then the temp sensor wires are pulled, the gauge goes to the half way mark.

I've checked the temp sensor for resistance, shows about 14-15 Mega Ohms. It never stabilized on exact number.

I was on another forum the other day and found out that the original ECTS (engine coolant temp sensor) is very, very bad on Saturns. The new ECTS that Saturn has now is much higher quality and is made of different components than the original. Maybe you could try to replace this part. The part costs $20 and is simple to replace. Perhaps it could help.

Here are the instructions on how to replace the item, just click on the link below:

http://www.saturnfans.com/forums/showthread.php3?s=&threadid=24003

Yep, that's what I thought and read elsewhere to.
The new ones are made of brass instead of some cheap resin.
Worth a shot...

Ok here's an update:

changed out the temp sensor today with a one from Saturn, also the Thermostat (the new, 1week old, one was stuck open).

Filled her back up with 50/50 dex-cool/h2o, rest the PCM, ran it for a few minutes with the heater full boar. checked the coolant level. OK so far. After 6- 10 mintues, All seemed OK, woohooo, ya right, seen this before. Time for a test run. From my home to the freeway is about 3 miles or so. Gauge @ 1/2 way mark and climbing. Got up to speed and gauge climbed to the RED! FUCK! Kick on the heater, gauge drops to 1/2. Ok so home we went. The Fan is blearing like a jet, cracked the top slighty on the overflow tank to relieve some pressure. about 3 minutes later the fan goes off and I can remove the cap. Check the temp of the coolant in overflow: approx ~205F.

Ok here's an update:

changed out the temp sensor today with a one from Saturn, also the Thermostat (the new, 1week old, one was stuck open).

Filled her back up with 50/50 dex-cool/h2o, rest the PCM, ran it for a few minutes with the heater full boar. checked the coolant level. OK so far. After 6- 10 mintues, All seemed OK, woohooo, ya right, seen this before. Time for a test run. From my home to the freeway is about 3 miles or so. Gauge @ 1/2 way mark and climbing. Got up to speed and gauge climbed to the RED! FUCK! Kick on the heater, gauge drops to 1/2. Ok so home we went. The Fan is blearing like a jet, cracked the top slighty on the overflow tank to relieve some pressure. about 3 minutes later the fan goes off and I can remove the cap. Check the temp of the coolant in overflow: approx ~205F.hi,just read your message on overheating.i had the same problem with a 97 sl2.i found that there's a metal tube that comes out of the head right above the upper radiator hose that was plugged.it goes from right above the upper hose to the resevoir.take it off and blow through it.it should be clear.good luck!DAVE

This is a real mystery. You said you measured the temperature of the coolent in the overflow and it was ~205 degrees. This means the engine is getting the coolant and is using it (or it gets "stuck" someplace and just gets hot). But why is it overheating? You changed the sensors, the water pump, fan, and thermostat. I would do what rebop46 suggests. If that does not work I would post something at saturnfans.com and see what they have to say because you are only getting 2 sources of input here and I am out of ideas. As a side note, that really irritates me that they put the green antifreeze in your car at the shop. GM is the largest car company and it is the mechanics job to know better. When I got my Saturn I had to flush everything because the green antifreeze was in my car too. I am going to do more research and in the meantime...good luck.

Another update to the mystery.

Today I had a buddy check things out. He's been baffled to. So, From what he thinks is that either there is a "clog" somewhere or that pump is bunk. Why? well, we brought the car up to temp in a stand idle ( the the point of the fan kicking in) The top and botton Rad hoses were NOT hot at all. Then drove around the parking lot a little to RED, still the Rad hoses were not hot..Hmmmmmm. No Flow?? or almost none??

and I have posted this little story on saturnfan as well. Thanks,

Another update to the mystery.

Today I had a buddy check things out. He's been baffled to. So, From what he thinks is that either there is a "clog" somewhere or that pump is bunk. Why? well, we brought the car up to temp in a stand idle ( the the point of the fan kicking in) The top and botton Rad hoses were NOT hot at all. Then drove around the parking lot a little to RED, still the Rad hoses were not hot..Hmmmmmm. No Flow?? or almost none??

and I have posted this little story on saturnfan as well. Thanks,

I had a 77 Firebird that I had just put a new water pump on
because it was leaking. Damn car overheated right away.
I let it cool off, recovered my coolant and just added plain water to test with. I pulled the upper hose lose where coolant travels from the water pump to the engine and started it up. No flow at all. Bad Pump.
A new part can be just as if not more suspect than an old one.
I looked at the bad (new pump) and the pully would spin but not
the, ummm, how do I call it, "thing that makes the water flow"
was spinning independantly of the pully.

You should get a diagram of coolant flow so you can trace the
flow from one part to another using just plain water with a cold
engine on each test. Cover your electrical stuff to minimize the mess.
You also may have to "improvise" some sort of way to test with
old radiator hoses connected together and routed upwards so
gravity does not fool you into believing the pump is working.
DO NOT LEAVE THE ENGINE RUNNING FOR MORE THAN 30 seconds
after the tstat opens during a test. Thats all you need to check flow. Let it cool down between tests. Remember you have to wait for the
t-stat to open and have a buddy watching the gauge and
working the ignition for you.

I am not sure if you can pull a cap and see the water move at
the moment the t-stat kicks open but that is another way to
test. Just be CAREFULL!!! On older cars thats what I do. I
look down itno the radiator at the moment water begins to
flow, stick a meat thermomenter into the radiator at that point
then go look at the gauge. This tells what temp the t-stat is
opening and how well the pump is working. Revving the engine
will also make the water flow faster of course. Just look out when
you back off the throttle. Coolant has a nasty habit of spewing out
of the top of the radiator when you do that.


You'll find it.

Ok so I took it back to the guys that did the pump.

At first they thought I was nuts. It wasn't getting hot for them. I told them that it happens when you DRIVE it. They put it on their Dyno to simulate a load, still not hot. ARGH! So I show up, and take it for a drive to prove to these fools I'm not crazy. when I pull up they soon believe.

The coolant in the expansion tank is bursting and the rad hoses are cool to the touch. they are stumped. the lead mechanic looks it over for over an hour or so. He bleeds the system, fills the coolant, has it running with the cap off the tank, and BAM! coolant spewing out. Still the rad hoses are cool to the touch, but the small metal pipe and return hoe to the Expansion tank are hot!. If either is the Rad hoses are squeesed, you can feel it on the opposite hose and see the fluid in the E-tank move. He's tripping out. When the car is turned off, then the rad hoses become hot. Lame ass couldn't test the E-tank pressure cap, he said he didn't have the tool for that kind of cap. He was also stumped in why the system wasn't pressurizing. All he could say was take it to a radiator/coolant shop...UGH!!!!

Rattus,

It sounds like you are narrowing down on the problem. Please post the updates. I am curious to know what was wrong with the car.