Coolant reservoir Boiling

[screamineagle88]

The question here is what the source of the problem is.
Since there is no steam coming from anywhere you can rule out a hose or piece of tubing. It’s not leaking out of the engine.
Other causes of overheating are inoperative cooling fan. Once the car is hot the cooling fan should be on. It should also come on when you turn your A/C on. If it doesn’t, try hooking 12 volts straight to the fan motor via the inline plug to that motor. If adding direct power to the motor doesn’t turn it on then your fan motor is bad. If it does, then your water temp sensor is the next possible culprit.
Another thing to check is your upper radiator hose. Be careful, it should be very warn (hot) and be somewhat firm while the car is running. If your wearing gloves you might even be able to feel the coolant flowing through the hose. If you can easily squeeze it then your could possibly have a bad thermostat that is stuck closed. You’ll need to check that.
Bad timing is another area that can cause overheating. But in most cars today an overheating issue caused by timing isn’t very common. But it is on the list of possibilities.
Your radiator could be plugged up with sludge and need a flushing.
Check your lower radiator hose to make sure it isn’t collapsing while the car is running. The lower hose (or intake hose) should be rigid at all times. Most (but not all) lower hoses come with a spring inside in them for support and to keep them from collapsing. If you check this and the spring is missing, call a parts house to see if they have your lower hose for your car, and if it indeed has a spring in it.
An internal gasket leak can be checked in a few ways.
When the engine is cool you can remove the overflow cap and start your engine. If you immediately see bubbles in the overflow then it COULD be an indication that pressurized cylinder gasses are being pushed into the cooling system.
Another test would be to check your oil and /or coolant. If you see coolant in your oil, or it is a milky brownish color, then you have a real problem and should not run the car until it’s fixed. If you see oil in the coolant, then it is a good possibility that you have an internal sealing problem.
But again, if your coolant is a milky brownish white, do not operate that vehicle.

I believe Eric has done a couple of vids on over heating problems and how to track them down. I would strongly suggest you give them a look.

Good Luck.

Topic

[Rob]

thats is uselly a sign you have air in the line if someone replaced some parts resently or you have a blockage….
is that a pressure reservoir or non-pressure tank.???
if non-pressure tank replace the rator cap and theriistat… I would also check the water pump… also if someone didnt burp the system you could of got that… I would also check when you turn on the heater you should be getting heat coming out… that could be a sign you have a clog in the heator core or your water pump is not working…. also like the other guy was saying… when the thermistat is open.. the upper heater hose should feel like the same temp as the bottem hose… if not your not passing coolent throw the system… those are the thing I would check out also would rec doing a flush where you then can test the flow of the system on each component of it

[Jake F]

This might be dumb but maybe there’s water instead of anti-freeze in your system. There’s a cheap probe to buy that can check the thermal resistance of your liquid. I doubt the OP will respond with an update.

[Matt]

I had this happen to my Ranger. It was a 60-75% blocked radiator. Pretty obvious when after all warmed up, the lower half of the radiator was still cool to the touch.

[Author]

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