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Still overheating after fan replaced

G

Griffinej5

Junior Member
I have an 06 equinox with 194000 that is overheating when idling. Cools when I start driving. Had the fan replaced last week. They said the head gasket was okay. I got it back last Wednesday, drove fine over the weekend. Pretty sure I was in traffic some that it would have overheated some. Come Monday, it's overheating again in idle. Fan kicks on once it gets somewhere between half and 3/4 of the way up, and continues to run once it's shut off. I added water to the coolant, that did help in the past. Didn't really do much here.
Should I try a new thermostat? Would it help to burp the cooling system? Go yell at the garage who did the job on it?
 
I added more water just now to replace what boiled out last night. Just ran it 10 minutes in idle, never went past about 1/3 of the way up. Last night and before the fan was replaced, it would have been half way at a long stop light.
 
Almost sounds like the low speed fan setting is not working, and the fan is only working at the high speed setting?

It is not coming on at the lower temp, but only at the higher temp?

I think there are normally two stages with the rad fan, and it almost sounds like your first stage is not coming on.
 
Have you power flushed the radiator also. Are the fins clean and straight?

If that is gunked up or damaged; then you have less cooling capability.
 
Could be radiator gunk. Careful, the gunk could be clogging up more than just the radiator. Perhaps the entire cooling system.
 
Griffinej5 said:
Come Monday, it's overheating again in idle. Fan kicks on once it gets somewhere between half and 3/4 of the way up, and continues to run once it's shut off.
Click to expand...
I'm assuming you mean the temp gauge. If that's the case it doesn't sound like it's overheating. The coolant temp will rise to a point where the fan will turn on. It is turning on based on what you're telling us and it's turning on well before the temp gauge is pegged. I would like to hear some clarification on this before commenting further.

Does the vehicle have functioning air conditioning? When the air is turned on, the radiator fan should turn on. Is it? If not, that needs to be corrected and it could be the true source of your problem

It is important to have the cooling system filled with the correct mixture and to have all the air removed from the system. I would consider no air in the system to be more important for troubleshooting purposes than a true 50/50 mixture of coolant.
 
could be a water pump going bad. if its not pumping enough fluid at idle it will overheat, regardless of fans coming on at the correct temp. or it could be a clogged radiator, or dirt in the fins.
 
It isn't typically dropping coolant, only when it gets overheated, and it's boiling out. Air is functioning and is ice cold when turned all the way up. I ran it in idle this morning with the air cranked. It still has some coolant in, not sure of the mix now.
I had it done at a private garage, and they used the red coolant recommended for the car after replacing the fan. I can try to burp the system and or flush it tomorrow or Thursday. I'm about to head out, so I'll have to see what it does while driving.
 
I'm not sure if your car has a pressurized coolant overflow tank vs. a conventional coolant overflow tank with radiator cap but if it's the latter and you have an old radiator cap, you should replace that cap.
 
oldsmoboat said:
If you are only adding water, that may be your problem. You need 50/50 coolant/water.
Click to expand...

That isn't the problem. Coolant is there to keep it from freezing, rusting, and raises the boiling point a hair but if you are running hot enough for that to matter you are already over heating. Antifreeze cools worse than plain water.

It could be all kinds of things. You need to check and see if the fan is coming on next time it starts running too hot. Could be a sticky relay, a sticky thermostat, an iffy temp sensor, air pockets, and a bunch of other stuff.
 
tortillasoup said:
I'm not sure if your car has a pressurized coolant overflow tank vs. a conventional coolant overflow tank with radiator cap but if it's the latter and you have an old radiator cap, you should replace that cap.
Click to expand...
That's good advice and I'll bet that's the problem. It has a threaded, pressurized radiator cap that is plastic. It also has an overflow tank that is not pressurized with a plastic cap. (I make this distinction Griffinej5 because you want to replace the radiator cap not the overflow tank cap.) This, from what I can tell at RockAuto.

From Griffinej5's last post it does not sound like it is actually overheating it sounds like the coolant is boiling out because the cap is not pressurizing the system.
 
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LTC8K6 said:
http://www.engineeringtoolbox.com/propylene-glycol-d_363.html

It would appear that a 50/50 mix of propylene glycol makes the water all around a much better coolant.
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It improves the boiling and freezing points, but degrades the specific heat capacity and viscosity.

50:50 water😛G only has a specific heat of 0.85 - which means that you need to pump 1.2 litre of 50:50 to remove the same amount of heat as 1 litre of water. The viscosity is also higher. Water has a viscosity of 0.3 mPa.s @ 90C, whereas 50:50 PG:water has a viscosity of 0.8 mPa.s - so there is more energy loss in pumping the coolant.

Ethylene glycol has much better viscosity at low temperatures than PG (@-40 C, 50% EG has a viscosity of 50 mPa.s while 50% PG is about 400 mPa.s) , and also a better heat capacity.
 
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boomerang said:
That's good advice and I'll bet that's the problem. It has a threaded, pressurized radiator cap that is plastic. It also has an overflow tank that is not pressurized with a plastic cap. (I make this distinction Griffinej5 because you want to replace the radiator cap not the overflow tank cap.) This, from what I can tell at RockAuto.

From Griffinej5's last post it does not sound like it is actually overheating it sounds like the coolant is boiling out because the cap is not pressurizing the system.
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My dad's Saturn just went through the same thing. Same symptoms as OP. His cap is a combo overflow/pressure cap. New cap fixed the problem.

Not sure if OP's vehicle has a bleed valve for the system, my dad's car does not. In my experience, air in the system causes the heater core to not work properly, and/or fluctuations in the temperature gauge.

As already posted, the pressurization of the system is a lot more important than coolant mixture.
 
GM? Equinox? 3.4l?
If it's anything like every other gm 3.4l I've come into contact with..
Most likely:lower intake manifold failure.
Have you had it pressure tested?
 
inachu said:
Also the radiator could be partially clogged.
Click to expand...

This, I had a car that would teeter-totter on overheating in traffic, I checked the radiator and it was just full of gunk, I had always kept up on coolant changes as well, I guess it just happens sometimes no matter what an owner does. As previously pointed out DO NOT just add plain water in it, this should be done only on an emergency basis, get a new radiator and thermostat and you will be fine, easy to install to boot.
 
Griffinej5 said:
I have an 06 equinox with 194000 that is overheating when idling. Cools when I start driving. Had the fan replaced last week. They said the head gasket was okay. I got it back last Wednesday, drove fine over the weekend. Pretty sure I was in traffic some that it would have overheated some. Come Monday, it's overheating again in idle. Fan kicks on once it gets somewhere between half and 3/4 of the way up, and continues to run once it's shut off. I added water to the coolant, that did help in the past. Didn't really do much here.
Should I try a new thermostat? Would it help to burp the cooling system? Go yell at the garage who did the job on it?
Click to expand...

Did the garage...

test the thermostat?
flush the engine?
use a vacuum device to pull out trapped air in the block water passages?
check the rad is not blocked on the outside? or on the inside?
use a normal prestone/water coolant mix?
check ignition timing and look for any computer codes?
check the rad hoses are good?
check for exhaust gases in the coolant?
 
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