Coolant lose

[e34_spangler]

Ok so I'm loosing coolant enough to throw the light about every three days after filling up obviously. I bypassed the throttle body all new hoses and new cap. And there's no sign of a bad head gasket plus the guy before me had a headgasket done. It seems that I loose collant more when I redline the car so is this common cause when I drivr normal the car doesn't seem to loose coolant aby ideas?

[jlevie]

First eliminate any easy to find leaks with a pressure test of the cooling system. If that doesn't solve the problem the next possibility is a head gasket leak that is pressurizing the cooling system, causing the cap to lift, and coolant to be dumped overboard. That may only happen while driving and leave no evidence.

[e34_spangler]

Ok well I guess its the head gasket but should I see signs that a head gasket is bad

[FLG]

Borrow a pressure tester from a local auto chain. Will answer your questions without guessing.

Sent from my Galaxy Nexus using Tapatalk 2

[fronton]

Loose grammer is confusing. It sounds like you have a loose coolant hose that is losing coolant?

If you let the car sit for a couple days is does the level change or is there a puddle? If not, your engine is clearly consuming it through either a crack in the head or head gasket. The fact that redlining it seems to speed up the loss should tell you everything. Check your dipstick for signs of coolant.

[jlevie]

Ok well I guess its the head gasket but should I see signs that a head gasket is bad

What signs of a head or head gasket problem there might be depend entirely on the nature of the failure and how bad it is. Depending on the failure mode there could be oil in the coolant, coolant in the oil, white smoke from the exhaust, overheating, loss of heat, leaks from the seam between the head and the block, or simply an inexplicable loss of coolant after driving the car. It appears that you have the last symptom.

While not definitive, one DIY test is to remove/replace the cap when the engine is completely cold to relieve any pressure (the hoses will be soft). Then drive the car for a bit and let the engine get completely cold again. If the hoses are harder then, air is being pumped into the cooling system from a cracked head or a head gasket problem.

The definitive test is to pressurize each cylinder with 175-185psi for several minutes while monitoring cooling system pressure with a sensitive gauge. A rise in pressure is evidence of a problem. A negative result on a cold engine requires that the test be repeated with the engine hot.

In this case the history of a recent head gasket replacement means the chances of a head or head gasket problem are higher, especially if that work did not include a check for cracks and surfacing of the head when it was off.

[meengreene30]

A leaking heater core or valve could be it too. Is there an antifreeze smell in the car, wet driver side carpet? There are 3 8mm nuts that loosen up. mine did and leaked.

[e34_spangler]

There's no signs of a heater core there's no signs at all no I have a question probably a stupid one does the system run at a higher pressure when I'm full throttling the car ? Cahse I had a slight crack in my coolant reservoir smaller than a finger nail and no coolant came out when I had the car running and I looked under the hood so I'm thinking maybe only under heavy pressure it shoots out from thete its towards the top now I replaced it last night but I didn't have tome to check it cause of work

[jlevie]

The pressure in the cooling system is strictly a matter of temperature. It starts off at ambient pressure and because it is a sealed system the pressure increases due to thermal expansion. When the engine cools the pressure goes back down to normal. The speed of the engine has no affect on cooling system pressure.

That will not be true if there is a head gasket leak. A very small leak may not cause a fast rate of increase in cooling system pressure, but running the engine at higher speed will pump in air faster, thus raising cooling system pressure.

[e34_spangler]

Now that small crack could screw with the pressure and cause coolant to go out the overflow