overheating...

[bigjoe]

my car is overheating i replaced radiator, cap, t-stat. flushed several times, water pump is not leaking, can't find any other leaks. it runs fine, no water in oil, or oil in coolant, no water or steam out of the tailpipes. i tried to bleed the coolant after i filled the system with the t/b hose, no air came out. (i just took the hose off, is that right???)

if i idle it, the gauge very slowly creaps up till it looks like its going to overheat (i don't actually let) most of the time if i just romp on the gas, the temp will fall dramaticlly. cruzing down the highway is the same story. sometime it will not even try to overheat, others it won't cool off. i don't know whats up...please help.

BIGJOE

 

[GoofSHO]

Make sure your Fan is working.....Also....check / replace your sensors. If you have a thermometer, check your temp with that, The guage might be reading wrong.

B

 

[bigjoe]

fan is working...I replaced the sensors, but I don't have a thermometer. i re-blead the system. nothing seem to work. thanks for the tips, but the problem remains. anyone have any other ideas. I'm really stuck on this one. thanks.

bigjoe

 

[sho_me92]

it is normal at idel for the temp to go up and then it will kick on the fan and drop it a little and then when your driving it should drop more but the only other thing i could think of if your water pump the teeth are gone but i highly doubt that ..but the needle should stay between the o and a in normal.

 

[Ishodu]

If its in the "NORMAL" range its generally normal. When you see it boiling over and what not that would be an indication that your over heating. Does it go above normal or boil over?

 

[SHOZ123]

It could possibly still have air in it. If the system is tight and leak free the air will work itself out after several cooling cycles. Keep the overflow tank full.

Or it could be worn impeller blades on the water pump.

 

[bigjoe]

should the upper hose be firm after heating engine up???

the gauge will go above "n" i'm not brave enough to find out exactly how high it will go. LOL! it boiled over once but that was do to a bad cap, it never went into the red.

the temp seems to drop all at once like a bad t-stat, how would you test one. the t-stat is new but you know how it goes.

could a bad head gasket cause this and have no secondary signs???

bigjoe

 

[Sh03d]

should the upper hose be firm after heating engine up???



could a bad head gasket cause this and have no secondary signs???

bigjoe

Yes, and No.

 

[bigjoe]

what if it's not firm??? t-stat not opening? big air bubble?

spent an hour letting it idle with the cap off, and squeezing the hoses, and goosing the throttle. got alot of air out, but it's still getting hot. let it run up till the needle was a hair under the white line, but it never boiled over. would that be hot enough to over heat it, or will it actually need to go into the red?

could a gauge spontanusly start reading wrong, even though the sender is brand new?

i love my SHO, and it hardly ever needs any work other than maintance, but when it breaks its such a PITA!!!

bigjoe

 

[SHOZ123]

If you have 15 lbs of pressure in the system it should be firm. Still sounds like a cap issue to me, or some other reason that you are not building up pressure.

 

[chknhwk]

it is normal at idel for the temp to go up and then it will kick on the fan and drop it a little and then when your driving it should drop more but the only other thing i could think of if your water pump the teeth are gone but i highly doubt that ..but the needle should stay between the o and a in normal.

Great tech! I have a question though. Why do you doubt the water pump teeth would be worn down? My car is exhibiting the same symptoms as above and I've been wondering what would be doing this. My fans are coming on but if the car is idling or driving slow in traffic it overheats. Like I said the fans are coming on but there's VERY little heat in the air, almost like it's not pulling any heat out of the radiator which makes me think the fluid isn't circulating through the system like it should.
I'm going to try to bleed the system first and see where it goes from there...