oceanarcher....it overheats just sitting in the driveway.

timmerz... seems like im getting good air flow. in fact...i replaced the fan motor yesterday as someone else suggested but it made no difference. still blows the same and still overheats. (brand new fan motor)

another symptom... i should have thought of this a long time ago.... i used my code scanner and got a code 15 (coolant temp sensor voltage high). i replaced it (for the second time since this started) and it made no difference.
something i forgot to mention early on (code 15 reminded me)...while doing the tune-up, i pulled the wire for the coolant temp sensor by accident and it came loose from the in-line connector that has the shrink wrap around it (not from the connector that goes on the sensor). i couldnt get the connector back on the wire so i removed the connector and spliced the two wire ends together for a good connection. i wonder if that might be causing an issue?

 

Could be a factor, maybe a BIG one...let's see if the guys think so...that code is huge, might be the entire reason you're having a problem...and possibly the wire you pulled might have another fault other than where you spliced, due to the stress of the pull...
That's got to be the main problem, at least I think you might have narrowed it down to the nubbin...

 

CadMan --

I guess I asked my question the wrong way --> does the car overheat when driving at freeway speeds?

The reason why I'm asking ... there's a possibility that your fan is failing to turn fast enough to cool the engine while sitting still

 

It sounds like you may have damaged a wire/sensor/connection when you did your tune-up. Timmerz is probably correct.

Also heat coming from the heater core doesn't indicate good flow , only that hot water is present. So a blockage in the radiator , heater core or engine is a definite possibility.

 

actually, i have not driven after the tune up. i've been afraid to get stuck. i'm not sure if it will overheat at freeway speeds. it started overheating the first time i started it after the tune up and ever since. however....it never overheated before the tune up. the fan cooled it down perfectly once it reached 3/4 temp.

i checked the sensor wire and the splice i made it tight and good. i removed the elec connector from the sensor and inspected the connector/wires and it looks fine. there doesnt seem to be any other damage other than the two ends i spliced back together on one whire. the other wire going to the elec connector still has the metal connector peices with heat shrink inline and those are still connected good.

what i pulled out by accident was the wire from one inline metal connector. i couldnt get it back into the connector so i removed the connector all together and just spliced the two ends together. thats the sensor i'm getting the code 15 from. (high voltage). other than the splice....the wires look perfect so i'm not sure what is causing the problem.

 

As others have suggested check the condition of the oil if you haven't done so already. (eliminate possible failed head gasket)

 

A failed head gasket will usually result in persistant bubbles in the coolant, along with an oily scum. Water in the oil looks like coffee with cream on the dipstick (don't drink it though, lol).

 

As far as the CODE 15 goes, it's just telling you that the sensor circuit is inoperative. Hit the local GM(saturn friendly) dealership, and get a new sensor and connector both. Will cost you about $40usd

 

i've replaced the sensor already..but not the connector. i'll try that and see what happens.

i checked the oil...it looks fine. had an oil change as part of the tune up (jiffy lube)

 

check for leaves or trash or mouse nest between the condensor and the radiator.