Water boiling out of the radiator cap

ANSWER : Hello – although this cooling system hose looks much like an octopus, it can be changed without removing the radiator. It does require small hands and a bit of "technique". For assistance, I would recommend a radiator hose service by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : Hello – you may very well be correct. Given your symptoms, it sounds like you have a blown headgasket. This can be confirmed by checking for low compression between adjacent cylinders, white steam or smoke from the exhaust (smells sweet), and chemically checking for combustion gases in the engine coolant – the "gas" smell you notice in the coolant already. I would recommend an engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : Based on the information you provided, It sounds like you may have a blown head gasket. What happens is that the high pressure in the combustion chamber squeezes its way through a break in the head gasket into the coolant passages. The result is pressure build up within the cooling system that could push coolant out into the overflow tank. Be sure to check your oil to see if coolant has contaminated it. If so, it will look milky.

I suggest getting help from a certified technician, such as one from YourMechanic, who can diagnose the possible leak and perform a quick test to determine if combustion gasses are getting into the coolant. Best of luck.

ANSWER : Hello. There can be a few possibilities that can cause the overheating condition. Have the radiator and pressure cap tested to make they hold pressure. Look for leaks at the water pump. The pump will show leak coming front the front of motor and will drip off of the crank shaft pulley areas. If pump is leaking, then replace the pump and thermostat.

ANSWER : Hi there – I suspect your radiator is clogged or otherwise corroded so that it is not shedding heat as efficiently as it should. Idling with the heater on was getting rid of heat without loading the radiator. When you’re driving, the engine is generating more heat than both the heater and radiator can get rid of. Checking the difference between hot coolant going to the radiator (top hose), and going back into the engine (bottom hose) may show that there is very little temperature difference. This means the radiator is not doing it’s job, and need to be professionally cleaned or replaced. Good diagnostic effort on your part to avoid the obvious "it’s another Northstar head gasket" diagnosis! For confirmation, I would recommend an overheating inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : If your cooling fans are not coming on, this suggests that either the fans themselves are faulty, the relay switch is not working properly or the coolant temperature sensor is not working properly. If the car is still overheating, this may suggest that the water pump may also need to be replaced. I would recommend having a professional from YourMechanic come to your location to properly diagnose your cooling system, and make necessary repairs.

ANSWER : Hi there. Assuming that the new water pump was correctly installed, it’s more than likely that you have a blockage or obstruction of debris inside the heater core, the radiator itself or the cooling system hoses. The best way to pinpoint the source is to have a professional mechanic complete an overheating inspection.

ANSWER : Hey there, thanks for writing in about your 2004 Buick Rendezvous. When the engine is cold, the thermostat will remain closed and keep coolant circulating through the engine to be warmed up faster. Once the coolant inside reaches operating temperature, the thermostat will open and allow coolant to flow to the radiator. If you are getting no flow at all, even with the engine getting hot, then the water pump may be faulty. If you need help having this looked at, a certified technician can inspect the system and replace your water pump if necessary.