this sounds like a bad thing to me...like the reservoir and/or the cooling system, has no antifreeze in it and heat from the engine is exiting through the cooling system. Does your temperature gauge read in the normal range? Is the car running OK? FriPilot
Yes- coolant reservoir is designed to accept excess coolant - As coolant heats up it will expand and flow to the coolant recovery tank (reservoir) and as it cools (contracts) it will be sucked back into the radiator
it is normal, when the coolant is hot and pressure built, the pressure cap allows the coolant to drain to reservoir to reduce pressure in the cooling system But, if it continually does this whereby the reservoir overflows and the vehicle overheats due to a lack of coolant actually in the radiator when cool, there may be an overheating problem or blown head gasket on the engine.
In all probability you either have a bad radiator cap or an air lock.
Is the temp. light coming on? Check your coolant level in the overflow reservoir If the level is to low it could cause the fan to run more than normal. I have a 2002 Sportsman 500 and my light was coming on and the fan was running more than normal. I had a pin hole leak in the tubing between the radiator and the overflow reservoir This was causing it to leak antifreeze and allowing it to suck air into the cooling system. Which was causing my fan to run and my temp light to come on.
If it's the coolant level light then the sensor may be stuck. I'm not sure if the 330ci has a pressurized reservoir for coolant or if it has a normal overflow catch, but in a pressurized system the level sensor will be on the bottom of the plastic reservoir. Tap it a few times with the handle of a long screwdriver, it should dislodge the float. Also, disconnect the harness connector to the sensor and reinsert it a few times to remove any corrosion.
It may be normal operation assuming all fluid levels are proper.
You may have a faulty coolant level sensor
your Toyota should have an overflow bottle to retain the antifreeze during normal operations. Unless it is overfull, I would be looking for a leak.
Because the coolant is starting to age and is picking up contaminants.This is normal, BUT, you want to ensure the coolant is replaced before too much longer.I rather change coolant too soon / early than too late.
There could be several reasons. Under normal operation, the vehicle will experience this as the coolant heats up and expands into the over flow. A bad water pump, low level of coolant, as well as a clogged radiator could also cause this problem.
The cooling fan temp sensor detects the coolant is hot and it will remain on until the coolant cools down, usually in a few minutes. Check the coolant reservoir to be sure the coolant is at the proper level. Must be an import.-Normal.
When the Engine is warmed up the liquid should be about 2 inches below the neck of the reservoir. When cold about 2 1/2 inches below that.