My 99 monte carlo 3.1 112,000 miles over heats now in under 10 mins. Starts and runs very good but after 10mins or so the temp gauge moves up all the way (260) then the HOT light comes on and the car goes into emergency operating mode. ofcourse I then park and turned the car off. A couple of times I noticed the temp gauge go to 260 then back down to 190 or so, then back up then down again, could that mean anything? Coolant in both the radiator and recovery tank is good. Replaced the water pump everything was performed correct gasket well placed, bolts tight. Problem remains the same. Did not replace the thermostat, couldn't find it, still not sure where it is but thats my next step. When it over heats quite a bit of steam shoots out from between the water pump and the power steering reservoir, cant see exactly from where but hear the steams hissing sound from there, looks like a wet trickle I see towards the engine, but not sure. Oil is normal. I did notice something very unusual, after runnig for more than 15 mins, that the upper radiator hose was warm only not HOT at all and the radiator cap was cool too, could that mean something? Aren't they supposed to be very HOT? I hope its just my thermostat and not a head gasket leak. Can any-1 give me some good advice? Is there any type of application or spray I can use to make it temporary-drivable? CAN YOU HELP?

 

sounds to me you have a t-stat issue and if you keep letting it over heat you could have more thne that goign wrong real soon.

to find your T-stat if you dont know where it is follow the top rad. hose back to where it meets the motor. then undo that big elbow it runs in to (also called a water neck) the T-stat is under it. replace it.and the gasket making sure you get it real clean in there before you add the new parts.

the T-stat not opening will cause the car to over heat. also normally your right the hose should be warm enough you cant touch it for any length of time.

keep us posted to what ya find

 

Thank you very much mickey, I think its a lot of work to get to that thermostat, what do u think? can I do it(LOL) do I need to remove may components to get to it? And can u tell me why the steam comes from where I said it comes from and also why the Rad cap is not HOT like it should be? Does a faulty t-stat keep the radiator, cap and hoses from getting HOT? T-stat I'm comming to get you, thanks again.

 

as far as getting to it most of the time they are pretty easy, I have the SS model so i dont know your motor.

but as far as the steam comming out , it might be a leak in your system there. or a weak spot so it is passing threw there.

as far as why it dont get hot, yes the t-stat can make it not get hot as it blocks the flow of water threw the system so it cant ge tthe heat out this is why it is causeing it to over heat.

if it blockeing the water it wont flow so it cant cicrulate threw the system causeing only radiant heat to move threw the system but it is not enough to cool your car or the water that is in it.

but if you keep going eventually you will boil all of the water out of the block and start to melt motor componets inside the motor if you over heat it enough and still drive it.

like i said it could turn in to a real mess. fix this and then drive it.


only other thing you can try is to squeeze the hose when it is warm and not hot see if it will allow you to do this. ( BECAREFUL!!!!!)
if you can do this with out any real force so the presure is not holding aginst you real bad you might make sure you have the right water pump on the car, Just becuse it bolts up dont me it is right for your car, and could be locked up aganst teh block.

take the hose off and try to turn the pullie if it turns you should be safe.

but i would think the pulley would seze on it causeing the belt to squeal and burn up. so i dont think this is a issue for you.

start with the T-state and see what ya come up with first. but stop driving the car till you get it fixed.

 

I agree with Mickey certainly seems like your T-stat is not working. The problem tou describe is exactly the same as what my old sunbird use to do.

And watch the over heating or you might crack your header, I've had this happen (stupidity on my part).

As far as the dripping coming from the around the water pump. I'm not sure if this is true for all water pumps but some have a built in weeping hole. I'll admit I'm not sure the real purpose but I did have a pump break down after over heating issues were would get coolant dripping out from this hole.

Also, one other note, if you do happen to be concerned about your header, check the color of you exhaust, If it is realy white in color and there is quite a bit you might have a problem.

Good Luck,
GWN
P.S.
Go get the Haynes Manual. It will give you the basics and help you with the T-stat location and replacement.

 

The weeping hole, I read very little text, about it in the auto manual some pumps do have them, however this very small leak supposed to be nomal after initially installing a new Pump, should stop doing that shortly after install. I will look into geyying the Haynes Manual, thanks. wil I need to remove many prts to get to the T-stat, thats all I want to know rihjt now. (LOL) maybe you can give my a brief idea which prts sure I can do this w/no/prob MUCH THANKS 2 ALL those that HELP.

 

Out of all the waterpumps I have installed I don't ever remember a new one leaking and having a break in period to stop the leaking. Sounds a little odd to me....

 

ummmmmmmmm no!!!!!!!!! they should be sealed when you put them on the car and stay that wasy till they are going to go bad, the weep hole is a eary warrning for you to know when the thing is going to go bad. that is all it is used for.
If it is leaking around it it means that you need to replace it and soon they dont last to long when they start to leak

 

99 Mt Carlo 3.1 Well had a hard time finding the T-Stat finally did had to remove a few things here and there to replace it but i did. "QUESTION" if the t-stat is not working right or not working at all, after removing it, is it suppose to open and close manually, (WITH YOUR HAND PUSHING AND RELEASING THE SPRING) or should it be damaged stuck not able to spring open/close??? Having a difficult time lineing up the fuel injection system (TRIM COVER) I think thats what it's called, I needed too bend it a bit in order to remove it now it's hard to line it up with the bolt holes, That's why they call me USELESS LOL but after all is done they call me USELESS # LOL. Maybe I can just Eliminate this COVER WHAT DO YOU THINK??? Can any-1 respond, thanks 2 all

 

About the only real way to test a t-stat is to put it in hot water to see if it will open up.. What I use to do is heat up a pot of water on the stove, throw the stat in and watching the center section of the stat for movement. It is not something that can be moved or tested by hand.