95 pontiac grand am overheating

[mystiocn]

HELP!!!! My car is a 2.3l quad 4 baught three years ago over heated in the red one time was low on antifreeze. over a period of two years was filling radiator with 50/50 coolant about half gallon every 2 months counldnt figure out were it was going no leaking on ground.January of this year car over heated going to pick up my husband going over a big hill both ways. so braught it in for a cooling system check determened at that time was leaking from the water pump and thermostat car was repaired was flushed, pressure checked and new parts. two weeks later again on the way to get my husband car was getting hot not in the red just hot and found it to be leaking from the rad cap. took it back to shop they replaced the cap and pressure checked it again said it should be fine 1 month later same thing leaking from radiator cap took it back replaced cap again and mech told me he thinks the radiotor needs to be boiled didnt have money at the time so just keep checking fluid level. did notice that if car started to get hot would put in park and rev up engine would drop down told mech he said no way would it drop that fast i said it does. finally this month 1 week ago got the money to boil the radiator said it was getting a crack along the side would be better to replace it so new radiator it is. new mech said he thinks the radiotor cap is bad because car over heated when he tried to bleed the air out.Took car back to first mech because it was under warenty he wanted more money to do the head gasket check we said no just replace the thermostate so he calls us after 6 hours tell us he didtn change the therm but did the check free of charge and said the head gasket was blown and the heater core was going bad come pic up the car. took car for second opinion 45 dollars more now we have put 700 dollars into this thing he did the check to test for fumes in the antifreeze said there was none also the other die test came back both neg for head casket malfunction but said the thermostat housing had a small crack and the heater core had a partial blockage also when he was tryuing to get the car to over heat it did got to 240 and and no fan came on so got his diagnostic tool plugged into car for comp reading and overheated the car again this time fan came right on at 226 tried several times to get it to overheat and have fan not come on so he could see if it was relay maybe wires or comp prob. car wouldnt do it again . FIGURES ALL sugestions welcome going to bleed the car tomorrow myself ,and get the therm housing and relays from junk yard if i can find them heater core needs to wait a while they want almost 400 dollars to replace that .o and yes i do get heat and air no prob did turn the air on when car was getting hot and temp dropped back down to 220 idling i am baffled read all forumes on here about over heating about 20 hours worth if i get this dang thing fixed she better be good for me for another 10 years she owes it to me for not putting her to sleep.

[xeroinfinity]

Welcome to AF !!

Sounds like air trapped in the cooling system.
Also a partialy clogged heater core can keep the air trapped inside, and gradualy driving you nuts with it getting hot and then suddenly dropping.

Did they happen to flush the cooling system when they replaced the radiaotr ??

[mystiocn]

yes they did but i also noticed something else today when we tried to get the air out car went into the red i reved up the engine in park dropped a few degrees did it again same thing and again did it about 4 times got it below 220 it was in the red um about 265to 270 when i push on the gas what the heck does it make go faster or open to let the flow of antifreeze bring down the heat im comfused

[crazy Jim]

If your temperature guage drops dramatically when you press the accelerator that is just the guage malfunctioning. No was can the engine temp drop in a matter of a few seconds.

[xeroinfinity]

Basicly you built up enough pressure in hte cooling system to move the air pocket that was probly trapped at the thermostat sensor.
So did the temps steady out after reving the engine ??

If the temps are not staying you could have a bad head gasket.

[mystiocn]

I swear car is possesed went to go to get something from my husband in salt lake, car got to the red pulled over took 5 minutes to cool down back on the road again about 10 minutes did it again . pulled over once more .did it again 10 minutes later. finally got to my husbands work let it cool for 15 minutes filled antifreeze because it was low of course from coming out of radiator cap drove all the way home started to get in the red but fixed itself twice did not overheat Grrrrrrrrrrrrr i think im going to get a priest to bless it lol j/k we are going to get the thermostate housing , the heater core, the relays and sensors replaced. If this car over heats after that , you will be hearing about a woman in utah who threw her car over the cliff because it wouldnt quit overheating .

[gaslight1]

have you back flushed the heater core as well as the rest of the system. it is a simple operation. remove and clamp off the heater hoses. put a length of hose on each nipple of the heater core and alternately run water through them.

[3100]

I heard about this idea before, so maybe you can try this it does not cost you anything
http://home.comcast.net/~pdxcgp/tstat.htm (just drill 2-3 holles) this could solve some air pocket problems

let us know if it helps, good luck

[skibum1111]

Personally, I'd put my money on the thermostat being bad or blocked. If the wrong t-stat was installed (which happened to me at a dealer) funny things will happen. Also, what is the condition of your heater hoses? If they are partially collapsed this will cause the same situation. When you rev a quad motor and the temp drops rapidly it's pulling more coolant from the radiator and forcing it through the block, causing the rapid cooling. Mine did this several times, once was a blocked radiator (never mix green and orange coolant, this will make a tar-like substance), once was a bad heater hose, and once was the wrong t-stat installed.