My radiator was overheating and I changed the cap and the top hose. I also did a pressure check; no leaks. However I sometimes check the fluid level of the radiator and it sometimes shows a reduction of fluid since the last time I checked it; which is every other day.

How did you check thermostat? Did you check coolant level. Is the auxiliary water pump leakinh

Possibly leaking head gasket. Easiest way to check would be to fill radiator full, start engine and watch coolant level in the radiator cap opening. The top radiator hose will become hot when thermostat begins to allow coolant flow through the radiator. You may have to top off the coolant. Still with the radiator cap off watch for water belching out of the radiator neck. If coolant does belch out of the radiator cap neck, refill with water. If it belches out coolant again it would be combustion gassed forcing the coolant out of the radiator.


This process should take about 1/2 hour to diagnose if it is a head gasket leaking combustion gasses into the coolant.


The radiator fan may run once car is shut off to cool engine compartment to prevent gasoline in fuel lines from vaporizing which would cause a condition called "vapor lock". A car won't start if fuel lines are vapor locked.

Good luck, I hope this helps you to figure out the problem.

Don't remove radiator cap when engine is hot.

Is your reservoir full to the right level? Check hoses for a leak. I would have the system flushed if there are no hose leaks in case air is in the system which can cause overheating. This can be done for about $50-$100 or less at many places. Sometimes when a thermostat is replaced the system isn't bled correctly. I hope its not your water pump, but it may be.

Good luck.

hello my8,
First confirm that the engine is actually overheating - steam, no heat to the interior etc. Sometimes a temperature sensor will fail and give a misleading 'overheat' reading on gauge. For that matter sometimes the gauge can fail and give the same misleading reading. Check that the cooling fan comes on when the engine temperature starts to rise above 'normal'. If not check (in order) fan fuse, fan relay, fan sensor, fan. Real overheating is caused by a lack of coolant AND/OR lack of coolant flow. Modern cooling systems are 'closed'. In other words there should be little or no loss of coolant. If the level is significantly low you have a leak....either external or internal. With the coolant topped up to the correct level and the radiator cap on, run the engine and look for visible leaks...hoses, valves, radiator etc. Internal leaks, eg. head gasket will usually be accompanied by white exhaust smoke (steam), hard starting, rough running and bubbles in the expansion tank. Sometimes, though NOT always, you will fiand the engine oil has a milky look and/or engine oil will be mixed in with the coolant.

Lack of coolant flow can be caused by anything in the system that causes an obstruction......in order of common occurance......thermostat stuck closed, radiator blockage, heater core blockage, water pump failure. One last point. because of design considerations many vehicles have the radiator mounted at a different level than the uppermost coolant passages in the engine thus trapping air in the coolant passages. In short the system must be bled of air in order to properly fill with coolant. Such systems will incorporate bleed screws usually in either the top/side of the radiator, the top hose, the thermostat housing and sometimes in all of these points. To bleed out the air do NOT run the engine as you fill the radiator. Instead, open all bleed screws. As you fill the radiator coolant will run out of one or more bleed points. Close this bleed point(s). Continue to fill until coolant escapes from the next bleed point then close that one. Proceed until coolant has escaped from ALL bleed points then continue to fill to the correct level. The expansion tank will have minimum and maximum level markings. Fill only to the minimum level mark with the engine cold.

hope helpful,
greetings

replace the cap , its allowing the system to over pressurize, also, you could have an air bubble thats moving around in the system, always make sure that you fill the radiator to just cover the radiator fins inside, this allows a place for expansion to happen. what you need to do is BURP your system, leave the cap off and start the vehicle, ( before doing this step,, make sure that you've replaced the thermostat, spring towards the motor , it only works one way!! ) once you see the fluid inside the radiator moving, it means the thermostat has opened, and your fluid level should drop down, slowly add more until the fins are just covered, and wait for it to close and recycle one more time, refill again, that should purge the system of unwanted air,, replace the cap, and fill the over flow tank to the lower level line,, and you should be set

check fluid level in radiator are you leaking fluid on ground does cooling fans come on if they dont check fuse for fans if fuse is good inspect wires going to fans are fan motors bad is water flowing thru engine anfter thermostat opens if notcould be bad water pump is there water on your oil dip stick if so blown head gasket dont keep driveing hot

Two things would cause this

There is a slow leak and the radiator is low on fluid

Let the vehicle cool down completely and then check the level in the radiator. I bet its pretty low. Top off the radiator with a 50/50 mix of coolant and water. start the vehicle and let it warm up with out the radiator cap on. Keep adding fluid as necessary. While waiting for it to warm up check around for any abvious coolant leaks. Things like hoses, radiator seams, water pump, water inlet/outlet gaskets. If no leaks are found it may be necessary to pressure test the cooling system and even then it might be a slow leak that only occurs when the vehicle is cold.

If the radiator is full than I would suspect that water pump is no longer working or creating enough flow. If the thermostat where stuck you would still get heat. If the water pump is not circulating coolant than you would get no heat and the car would overheat.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

There could be several problems with it overheating. 1. Low coolant level. Top off with recommended coolant. 2. Have the radiator cap pressure tested. A cap that cannot hold proper pressure can allow fluid to leak. 3. Spent coolant. When coolant breaks down, it cannot keep the engine cool properly. A coolant flush would be recommended. 4. A stuck thermostat. A stuck thermostat can impede the flow of coolant through the system. 5. Coolant leaks. It could be the radiator, water pump, thermostat housing, hoses, or freeze plugs. Have a pressure check done on the system. 6. Blown head gasket. When a vehicle overheats, it puts a strain on the engine and gaskets. Have a compression check done on each cylinder. These are some steps to take toward getting this issue resolved. Good luck.

your radiator is probably bad small leak but itll do its deal of leak...

Two possiblities; a blown head gasket, or a freeze plug leaking. If possible take it to a trusted shop and have the pressure checked on the radiator, they can tell you if your radiator is stopped up, or the freeze plug is leaking, and if it's blowing back in the radiator when you remove the cap then it's a blown head gasket.