If you have a stable level of clear OIL on the pan for a good while, If it's a headgasket problem that means the coolant found it's way to the combustion area, which means the compression / power strokes keeps pressurizing the engine cooling circuit, how hoses feel like after a while of driving? Hard due to an excessive pressure tells you that you have head problem either warped or HG is blown, if this is not the case, it could be the leak is behind your engine (freeze plugs), there's a chance the leaking coolant is being evaporated by the exhaust pipe.
Try to top up the coolant level and pressurize for a few minutes your cooling system when engine is cold and turned off and watch for leaks underneath your car.
Bad caps can also fail but not leaking from exterior, at rare cases, they can fail the way they let overflow coolant travel to the overflow but not from the overflow to the cooling system (one way), to check for this, Darin completely the overflow tank, top up your cooling system, don't add coolant for 2 days, that's safe however remember to keep an eye to the temp gauge. 3rd day drain the coolant found on the overflow tank and add it to the system through the radiator cap, if doing so and had the system topped up again (it might be there a small loss of coolant, don't worry about)
so you need a new OEM quality radiator cap.
Hope this helps,
Sep 13, 2013 at 10:01 AM
