Thursday, October 6, 2011

My car is overheating and i've changed the water pump, radiator and thermostat and it's still overheating

you might have a head gasket blown when radiator full and cool start engine with cap off.. if head casket water will blow out radiator inlet
My car is overheating and i've changed the water pump, radiator and thermostat and it's still overheating
The only things that are left are

1. Are the cooling fans turning on. Run your car until the temp gauge reaches about 220. Your cooling fans should turn on. If they don't you're looking at a bad electric fan motor, bad fan relay or bad fuse for your cooling fan.

2. Do you have enough radiator fluid in your radiator. That or you might have trapped air, double check to be sure that radiator is still full. If there's a radiator cap, you need to open the radiator cap (WHEN THE ENGINE IS COOL). If you have a leak, checking the resevoir is not good enough.

3. Make sure you don't have a broken head gasket, if you see a big plumb of white smoke out the tail pipe or if your oil looks a little like chocolate milk you've got a broken head gasket which will cause the engine to overheat.
My car is overheating and i've changed the water pump, radiator and thermostat and it's still overheating
If the fan is electric, does it work?
Quit spending money on it. Take it in and have it looked at.
Whoever worked on your car may have not done what they said they were doing; or your radiator hoses may have a leak; or something is causing your engine to not get enough air.
you could still have a bad thermostat check that first or a crimped hose
check your fan it may be a bad fan motor
Check to make sure your fan is working.....Electric (connections, fuse)....... Belt driven (belt condition, not slipping). Water pump pully/belt also should be checked. Check to see you have proper degree temperature for thermostate opening. Any fluid leaking... low water / higher running temp. You could also try flushing your cooling system and see if that helps.
You did not say what kind of car - which may have helped. In addition to the other things that were mentioned, if your radiator fan is not electric but rather thermostatically contolled - those also can go bad and the fan, even though it s spinning, is not spinning fast enough to keep the engine cool; insufficient air flow across the radiator.
I don't wish to make you feel dumb, but when I had this same problem, I felt dumb when I found out what it was. Here's what happened...

My van was overheating.

I had replaced the thermostat first because it was the most likely and the least expensive thing to do...but it didn't help. Symptoms were the same so I guessed I just replaced a good thermostat with another good one so left it alone.

Went to the pump, then the fans (wow, they use a lot of current!) then suspected flow through the radiator. Then I gave up with that and went back to basics.

I pulled the thermostat out ( and just put in a gasket). I got cooling!!! Now why? I got some gasket cement on the wrong part of the new thermostat and kept it from working right.

(I've even put them in backwards and had them not work for obvious reasons but I'm over that now. ;)

Reinstalling the thermostat properly fixed it for me.

Try removing the thermostat to see if it is your problem too. The test is cheap and doesn't take long.
Park on dry pavement(without AC having been on) and determine if fluid is being lost B4 overheating and boiling out.

Sealed system should not be losing any coolant fluid. It will rise as it warms into reservoir BUT if it has not been overfilled no leakage to ground should occur.

Dry and clean pavement makes it easier to check(as well as for any other fluids (except air/vacuum) that may be leaking.

Hoses new? That can be the original problem that is overlooked.

The older ones can be sucked flat with resultant loss of coolant flow. Should be stiff to squeeze without cracks. If they're three years old- REPLACE them anyway. All four(heater core).

Engage heater to lower temperature in an emergency. Full hot allows use of heater core(it is a mini-radiator). You may have air pocket there causing mischief as well.

No way those three All fail unless squashed in accident.

Is drive belt for water pump tight? Is replacement thermostat correct( temperature for opening)?

Is the coolant comprised off half(DISTILLED) water(NO corrosion) and half coolant??? Common perception is that coolant for COLD weather... actually more necessary for HOT weather(increases boiling point of water). HOWEVER pure coolant is NOT better as the mixture is what gives you a boiling point above engines operating temperature!

And a thought... overheating on gauge only? Never all the information needed for these questions- you're not alone.

Hope this helps... drop a line or ask again with the rest of the story... good luck and good night.
If this is an older vehicle and you are certian all of the cooling system is functioning properly then it is possible the timing is off and this can cause an overheating situation. You can check your timing with a timing light.