So I was driving it for the 1st time since the flush and my temp read normal until about 15 mins in. Then it almost hit full boil. I pulled over and popped the hood. Nothing was spewing out but I did hear a sloshing/bubbling noise buy the manifold area. Drove it home maybe another 5 mins and parked. Checked again and the overflow tank boiled over with coolant. Did I miss something?

 

Did you bleed out the air after filling up with coolant? If not then you could have too much air in the system.

After the MAX cools raise the front end on a hill or on jack stands. Take off the radiator cap then start the engine. Let it idle for several minutes until the needle reaches mid range. If it bleeds out air then add more coolant into the reservoir or radiator.

What type of coolant did you use and what is the coolant/ water ratio?

 

Prestone. 70-30 or so ballpark. I didnt have the cap off when I flushed it. Ran it thru 7 flush cycles. 1st ran prestone flush and distilled water. Heater on full blast for 15 mins. Drained. Then same steps minus the prestone flush until it was pretty clear. Then filled with coolant and distilled. Ran it at idle for 20-30 mins.

 

Sounds like you flushed it good so try bleeding out the air now. For the air to get forced out while the pump is circulating the coolant the cap needs to be off.

 

Raise the front of the car with a jack. Or park on a sloping driveway or on a hill.

Open the radiator cap while the engine is cool. Run the engine 15 minutes or so. The air needs to escape through the open radiator cap.

 

Will do. Thank ya'll for the advice.

 

So ran with yalls advice on running it with no cap to free up any air bubbles. Saw alot of air bubbles come up. Drove it and the temp rose again. Not nearly as quickly or as hot as the 1st time. Im going to keep running it at an angle and see if they continue to bubble out. I keep seeing the air release valve in my research which I didnt mess with at all from the get go. Could opening it if I were to know where it was help?

 

Ignore that.

Keep bleeding at a steep angle and topping off.
Make sure your overflow has some in it.

 

Bled it last night. Drove it to drop my son off this morn. My temp needle still goes over the half on the guage and keeps rising slowly. Drops back down when I put the heater on. WTF?

 

Keep your heater on while bleeding the system.
Are you sure you used at least a 50/50 solution of antifreeze?

 

Are your fans working properly?

 

irrelevant to the problem at hand

 

You didn't bleed it right. The heater has a small radiator that uses engine coolant to give you heat. When you bleed it, you should put the heater on full heat. Good luck.

 

Antifreeze also helps prevent overheating, so just tossing it out there.
Some people think that they would need a bottle of antiheat for that problem.

 

Did you check if thermostat opens? Also try to remove all the leaves/dust extra from between radiator and A/C condenser. I had one g35 that kept crushing the red zone after radiator and thermostat replacement

 

Bad water pump?

 

+1 on T-stat...replace with OEM if you've bled and burped the **** out of it.

 

Make sure you bleed it correctly before you go jumping to other things.

1. Park on incline if possible.
2. Take off rad cap.
3. turn on engine and turn heat on full blast.
4. push on the throttle under the hood to get water circulating. Increase slowly so you don't blow AF out.
5. squeeze hose going into rad on right side to get any trapped air out.
6. Turn off once it gets to op temp and let cool. Leave rad cap off.
7. When cooled, add additional coolant.
8. Repeat until you don't have to add any more coolant. it will likely take 3-4 times.

 

Actually, you only put antifreeze in there so the water doesn't freeze in the winter. BTW if you run straight water only you can add justice brothers cooling additive and your temps will be lower than normal but you can't use it with antifreeze. OP's thermostat might've failed.

 

Turning the heater on is only necessary when a vehicle has a cutoff valve in the heater hose. Maximas don't have this valve, so the heater settings will have no effect on bleeding, burping or flushing coolant.

Put the front end on ramps or stands and run for 15 minutes with the cap off. Listen for the fans to come on. Did you backflush the radiator? Were you overheating before all the work you performed?

 

So why is it always stated to turn the heat on Such a simple task and becomes such a p.i.t.a. Good luck

 

It also raises the boiling temperature genius.

 

The pressure in the system prevents boiling. Antifreeze does not prevent overheating...

 

Antifreeze has many purposes, foremost it is anti-freeze. It also inhibits corrosion, electrolysis, and lubricates the pump. Cooling is actually not one of its natural qualities. Antifreeze is less efficient than water at cooling, this is why there is a spec for mixing, to insure enough water in the mix to be efficient. A pressurized system also raises the boiling point to allow high enough running temperature to allow efficient combustion.

 

Because all car makers USED TO have a water control valve on the heater core that controlled the amount of coolant flowing through the heater core, thereby regulating the temperature. These valves completely shut off coolant flow when heat was not wanted, hence the instructions to turn the heat on to full.

Nissan last used a water shut off valve on the Maximas in the 1994 model. What year other manufacturers have made a similar change, I don't know. May some manufacturers still use a valve. So to avoid having to list all the different makes and models and years that truly need to have the heat control turned on max, the various places just say do it. If you have a car without a water shutoff valve, you are just doing something unnecessary, but not hurting or helping anything.

 

I'm gonna try and put my old thermo back in. I replaced it thinking that was the issue and in the end had to replace my radiator due to it being clogged up. The more I think about it the more I'm pointing my finger at it. The longer the engine runs while in drive the hotter the temp right? I just read a post and the guy did the thermo boil comparison and the aftermarket thermo didn't open near as far as oem. When the heater is on it stays cooler but to a point. It overflows after I drive it around. When the heater is off it overflows at temp. Wouldn't this indicate the thermo ain't allowing sufficant coolant flow to the block when not on as it overflows? Wish me luck and thanks for all the input. Results coming soon.....

 

http://auto.howstuffworks.com/cooling-system3.htm
Pressure helps, but so does antifreeze.

 

Give it a rest Fakie, the mixture ratio is not the problem here....

 

IJS...

 

It's possible that ethylene glycol could raise the boiling point since different liquids boil at different temperatures.

But I disagree with the link Farkie posted where is says that pressure raises the boiling point another 45 F (25 C).

This is a little optimistic. On plain water, 15 pounds of pressure will raise the boiling point to 248º F.

 

Did you ever feel the lower radiator hose? If it not hot then, it's a stuck closed thermostat. I think the reason why the coolent overflow tank is bubbling over is that the hot water has no where else to go.

 

Ahhhh...the missing details.

Dude, if you have a problem please post all possibly relevant info. It saves YOU time getting a diagnosis.