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View Full Version : 96 ciera 3.1 V6 cooling problems



rci2950
02-25-2008, 02:25 PM
My Ciera every so often the heater will go ice cold and the temperature guage will go way up. then as it comes within a hair of the red it will slowly go back down. then the heater starts blowing hot again. I replaced the thermostat and this didnt seem to help. Someone told me it could be a head gasket or cracked head. If that was the case wouldent i have coolant in my oil? Could it be a loose impeller on the water pump? Blockage in the rad? Im puzzled but would like to make an educated guess on what i will tackle next. I am thankful for any advice you can give.
Adam

bodega1027
02-25-2008, 04:25 PM
Hmmm... I've had my fair share of cooling problems over time, but with a new Thermostat installed, I don't know what to tell you. I'm no mechanic mind you, but I did once have a similar problem (intermittant overheating that a thermostat didn't solve)... I was in a hurry and in a pinch for cash, so I couldn't take it to a mechanic, so on a whim I flushed the radiator and crossed my fingers. That did the trick, but I couldn't really tell you why, other than I may have cleared up some debris (the coolant came out brick red at one point, so it was really time anyways).

Good luck!

rci2950
02-25-2008, 05:26 PM
also wondering where the temperature guage should be under normal driving conditions. before i changed the thermostat the temperature guage pointed half way between the quarter and half tank mark, now it is just below the quarter of a tank when warmed up.

bodega1027
02-25-2008, 05:29 PM
I'm running the same engine, with a new radiator and a fresh tank of coolant as of Saturday, and normal operating temperature on mine is between 1/2 and 3/4s (never QUITE 3/4s). Couldn't tell you if that's normal, just where I'm at.

Pushrod_V6
02-25-2008, 05:32 PM
My Ciera every so often the heater will go ice cold and the temperature guage will go way up. then as it comes within a hair of the red it will slowly go back down. then the heater starts blowing hot again. I replaced the thermostat and this didnt seem to help.

Are you 100% certain you don't have any air pockets in the coolant system from when you changed your thermostat? You may have solved your problem but created another if you are not 100% confident there are no air pockets, as a larger air pocket can create the problems you describe.

How long does your car need to be running for this to happen? Will it happen when the car is in motion, standing still, or both? Are your cooling fans coming on when the temp begins soaring?

rci2950
02-25-2008, 05:39 PM
Are you 100% certain you don't have any air pockets in the coolant system from when you changed your thermostat? You may have solved your problem but created another if you are not 100% confident there are no air pockets, as a larger air pocket can create the problems you describe.

How long does your car need to be running for this to happen? Will it happen when the car is in motion, standing still, or both? Are your cooling fans coming on when the temp begins soaring?

the car runs about 10 to 15 minuts before this happens. I am not sure if the cooling fan comes on, it happens when the car is in motion, if i pull over and put it in park it will almost immediatly cool back down. if i just slack off on the gas and roll it will cool down but not as quickly. Doesnt seem to happen when the car is in park but i might just not be giving it a chance to.

Pushrod_V6
02-25-2008, 05:46 PM
the car runs about 10 to 15 minuts before this happens. I am not sure if the cooling fan comes on, it happens when the car is in motion, if i pull over and put it in park it will almost immediatly cool back down. if i just slack off on the gas and roll it will cool down but not as quickly. Doesnt seem to happen when the car is in park but i might just be giving it a chance to.

OK..... so as your revs and load on the engine increase the temp does as well. One thing to check for to rule out air pocket - and for God's sake be careful with this - is once the car starts to have its temp rocket upward get out of the car and look at the expansion tank, and see if there is fluid in it and if the fluid is bubbling. If there is, ignore the next step.

If there isn't coolant in the tank, touch the radiator cap gently to see if it is hot. It should be. If it is cool to the touch, you have an air bubble that is working its way out. Get the car to a place you can park it and let the engine cool off. Fill your radiator and expansion tank to the "cold" level.

If your expansion tank has fluid when this happens, there is a good chance you got a bad thermostat - trust me, it happens as they make millions of these things a year. Replace the thermostat again. When you have the thermostat out re-fill the block with coolant at the thermostat neck before you put everything back together as that will virtually eliminate the chance of an air bubble from developing.

rci2950
02-25-2008, 06:01 PM
i just hope it isnt the head gasket. i would rather anything else. Would idleing it in the parking lot with the radiator cap to the first notch help get the air out? Someone told me there is a torx type screw by the water pump for getting the air out of the system. i wasnt really wanting to touch that because it looks like it has the possibility to start spouting like a whale. Also i had a pressure test done by a half with mechanic at a local value oil change place and he said there were no leaks... so since no leaks does that mean the head gasket is fine?

bodega1027
02-25-2008, 06:20 PM
Sidebar: I noticed that my radiator NEVER draws from reservoir (even when the radiator was empty and the reservoir was full), and that the cap doesn't fit very snugly. Could I have an air pocket too?

mickstan_VR
02-25-2008, 08:52 PM
Also, make sure you have the correct radiator cap. Your radiator should be drawing coolant from the bottle if it gets low, and pushing it into bottle if it gets too hot. Sounds to me like a pocket of trapped air in the system. With the engine cold, take the cap off, let the engine get warm and wait for the coolant to start circulating. Then rev it up. As the coolant level drops in the radiator, add straight antifreeze to it until its full, and put the cap back on quickly. It may take a helper to do this. If you got too much in it, it will puke it back out into the tank as it cools and draw whatever it needs as it warms again.
As far as the correct temp on the guage, it should be a little below half-way for normal. The fan should kick in at about 220-230. I think the actual temp is 232, but they all behave slightly different.

Tuddi
02-25-2008, 10:33 PM
Also, make sure you have the correct radiator cap.


Absolutely in agreement.

I'm using a 10lbs cap, but think I'm going for 9lbs. What is the lbs pressure for the original ones?

CieraSL92
02-25-2008, 11:23 PM
16. But mine has a 13.. No issues. My temp guage gets up to 220 in stop and go, fan comes on, cools back down.

CieraSL92
02-25-2008, 11:27 PM
Oh, intake gaskets on these were part of a recall I believe. That may or may not be accurate, but I know the 3100's intake gaskets were problematic.

mickstan_VR
02-26-2008, 12:00 AM
My 2.8 has a 15LB cap. That is also what the book says. Thermostat starts toopen at 188-193, fully open at 212.

Tuddi
02-26-2008, 06:43 AM
13-15 lbs... that sounds as if I can safely keep my 10lbs cap. I have not had any problems, but I have not noticed any movement of the liquid in the overflow tank.... but then again, I have not been driving much, and never gotten the engine very hot.

rci2950
02-26-2008, 05:09 PM
is it normal for there to be minor bubbling in the coolent tank? the overflow tube is blowing small amounts of air into the overflow tank. i have ran it this morning for a good 15 minuts with the cap off the radiator letting it spit and fart i then replaced what came out with fresh coolant. drove it for around 45 minuts with no replay of the heat issue, but whenever i lift the lid and look inside the overflow tank it is having nickle size bubbles about one per second. this is when the car is rinning and for a few minuts after.

bodega1027
02-26-2008, 06:03 PM
Don't quote me on this, but I do believe that this normal, and actually what you WANT to see... that there is flow and pressure between your reservoir and your radiator, and that any air pockets are escaping to... somewhere other than inside your radiator.

CieraSL92
02-26-2008, 10:51 PM
Yeah, that'd be nominal during bleeding (after coolant system has been opened or drained), but it should stop after the system's purged of air. So after 45 minutes of having coolant avaliable to it, it should have stopped. I would make another test run to see if it continues to do it, but it sounds like the head gasket is leaking. If it continues (and you know its not air) run a compression test. That will tell you the condition of the head gaskets