Originally Posted by TheMcCoy14
On the highway I run at 4k rpm I can't emagine that running on one fan alone would be able to keep it from getting a little hot. Checked the oil. It was a little low and just the usual murky half way between needing an oil change color. Why would the coolant come out of the radiator if the head gasket were blown?
That is really not an issue, we all pretty much run at 4K rpm on the highway.
I bet you anything you can drive for hours on end on the freeway at 4K rpms with your radiator fans removed, and the engine will not overheat at all. Getting in stop and go traffic, that's a different deal.
4000 rpm in top gear produces the sort of constant airflow through the radiator the fans would not even dream of producing.
The coolant would shoot out of the radiator in the test I described in my above post, because:
Let's assume the head gasket is blown for sure for a sec.
(I am not saying you have a blown head gasket. My post above also says "do this test to rule out the head gasket". There's nothing conclusive here. This example is just to illustrate the relationship between the head gasket, the coolant and cylinder vacuum/pressure)
A blown head gasket means the sealing capabilities of the gasket is compromised, and it can no longer maintain a seal between the cylinder pressure, oil, coolant, and the surrounding environment.
Since the most stressful duty of the head gasket is to contain the pressure generated by the cylinder, that particular area is naturally more prone to failure.
And, in cases where the coolant manages to make its way into the cylinder, where it makes its presence known to the rest of the world in the form of a white, sticky cloud which tends to hug the ground after "burning" during the combustion cycle, just the opposite, where the pressure generated by the piston moving up "leaks" into the coolant system also takes place.
And, this pressure leak into the coolant system is best observed at the lowest possible rpm levels.
The lowest possible rpm level of the engine is cranking rpm. Idle is much higher than that.
I have seen a water column shoot up about a foot in really bad cases.
There should be no movement with the water other than the slight disturbance associated with the vibration caused by cranking.
Please make sure your hoses are intact first.
Before you spend any money on expensive items, please have your radiator (along with the rest of the cooling system) pressure checked. It should hold 14 psi all day. If the pressure gauge drops rapidly, start looking...
(Sorry if I come across a bit confusing. English is not my first language.)