95GTFiveoh

Hey guys new to the forums,i currently have a 95 Gt stock 302.I am having some heating issues that i have had for quite sometime but just now getting around to fix it..i have checked the obvious,New rad cap,new T-stat.flushed the cooling system.let the car run forever to get the air bubbles out heater on full blast while running,i recently discoverd a crack in the radiator around the inlet hose on top of the radiator/repaired it today.So i read on some websites to take out the thermostat and see if it overheats,so i did and let it get to operating temp while sitting in the drive way it got to 190 sitting there then rose to 205-208 or so and the low speed fan kicked on and knocked it back down to 190 and so on,my question is what should it run just sitting there with no t-stat?with the 190-195 thermo in it was getting to 215-230 like the thermo was stuck shut..also didnt see the radiator circulating any water in the rad,but when i took the thermo out it had very good circulation,but the problem is,that i have replaced the thermostat 50 million times..everytime i get one i get a pot of boiling water throw iti n there and see if it opens,which they all do im clueless to why it runs normal with no t-stat but with one in it is overheating.For instance the other day at idle it was staying 200+ but i took it for a ride down the road and it went to 230 instantly so i shut it off immediatly..i havent drove it with out the thermostat so i really dont know what temp it would run going down the road..i also took the water pump off to find that the impeller is in good shape and turns freely put new gasket and put it back together now i am here..if anyone can help or has any idea id appreciate it p.s the last t-stats i took out yesterday did have the small circle whole in the t stat i guess so it dosent lock up or is easier to get the bubbles out of the system,all these thermos i have bought are from autozone -.- thanks!

dawson1112

Im curious as to how you are installing the thermos? Ive seen them put in backwards by mistake and they take for ever to open up if at all. So just to clarify , you are replacing the thermos back in the engine with the point out? and the long flat end facing the engine? I know it sounds crazy but I have seen it done countless times.



Black arrow faces away from engine

Red arrow towards engine.

95GTFiveoh

yes sir,spring in the block, and point towards the radiator,i have also heard it could be a headgasket but have not done a chemical test,nor a compression check but motor runs like brand new but yeah banging my head over here. the radiator is also an original ,when i flushed it yeah it was dirty,no signs of oil or any sludge just mainly rust looking water,also no water or coolant in my oil so =\

dawson1112

Haha well I had to make sure , you wouldn't believe how many times Ive seen pple forget witch way it came out.

Now on to better things...
Replace the radiator , I tried to fix mine with some epoxy , lasted a few days, tired to used jb weld lasted a few mins .
Just replace it friend.
It sounds like there is a blockage someplace I suspect the radiator.

Defiantly get the head gasket test done , you don't always see coolant in the oil. And usually that's the very first sign of impending head gasket failure is an over heating car with fully functional cooling system.

Whats your timing at? over advancing the timing can cause over heating as well.

BabyGT

A blown head won't always let oil into your coolant, it can be just between a coolant passage and the compression chamber. I'm with Dawson, sounds like best case scenario it's a blockage, worst case head blown. You've already replaced the other things that would come to mind.

Any leaks in the coolant system at all will have some pretty adverse effects.
Are you losing coolant at all?

95GTFiveoh

thanks for the quick replys,i do not know what the timing is actually set at,it has been that way for a long time,is there away i can reset it?like disconnecting the battery for 30 mins?i currently do not have a timing gun,and have never used one either,ive seen it done i know you shoot it at the lower damper pulley with the white line on it that has a bracket and a dime sized hole,if i can get one what do i hook the timing gun to?sorry didnt think about the timing.but no pings or knocks at WOT or idle i have set the timing just by ear,disconnected spot and turned the dizzy alittle but #1 plug wire is not past the 12:00 postion i dont think,but i will check it and i will also replace the radiator,i was going to ask is it true when replacing heads/gaskests your not suppose to use the same head bolts,there made to be torqued once and then you need new ones?i have worked on cars but never taken the motor down that far,have had the upper and lower intake off of this motor,and i also installed this motor/trans into this car i bought the body and wheels with no motor or trans.Deleted the frozen smog pump,replaced the belt with a shorter one.and all that engine,runs fine and no CEL.Ive replaced every 02 sensor.along with every other sensor on this car to get it to run like it is suppose to lol but now its overheating..figures,i hate to think its a head gasket but i guess they have to replaced sometime or another

95GTFiveoh

yes i was losing coolant,yesterday before i dsicoverd the small crack,i even overflled the water resivoir and came back hour or two later and all the coolant was gone out of the resivor but the rad had water -.- lol i am about to check it to see if the crack i fixed stoped leaking and if there is still water in the res/rad will report in 10 minutes thanks guys for quick replys

95GTFiveoh

ok just checked,the coolant is still there in the rad/resivor so i dont think i have any leaks now,one thing i did notice with out the thermostat in there when i reved the motor the top hose would flex a good amount,seems pretty soft but it is old dont know if it is normal or not but i guess it would be if the water pump is spinning faster,do you guys think that 190-205 is still hot with no thermostat in there?i havent taken it on a ride but it should run cooler in theory with the wind cooling off the rad but who knows

dawson1112

With no thermostat in the system it will take a lot longer to over heat . But it will over heat eventually.

The system is designed to leave the water in the block a certain amount of time to pull heat from the engine, as well as allow time for it to cool in the radiator. With out the thermostat the water flows freely through the system . This free flowing water will start cool then gradually start to rise in temp as a whole. It will not have ample time in the radiator to maintain a certain temp.

You need to have the thermostat in . If that upper radiator hose gets a lot of pressure in it when you rev it up that is a good sign the head gasket is going bad.
Or there is a serious blockage in the radiator and the water is entering faster than it can escape.

95GTFiveoh

well crap that figures,i guess il try to get a chemical test or a compression guage to check to see whats going on,if it checks out fine i will get a radiator and go from there,thanks alot for the help and replys i will open the thread again when i have new,news thanks again!