Radiator Problems

awishawash

Hey all,
My car has a problem. It stops driving when the temperature gauge goes to the top. So I wait for it to cool down, and fill the radiator up. It drives fine. 4 days later same problem. The radiator will take about another 2 litres of water. It does not appear to be leaking, and the overflow thingy for it gets pretty full. I was told it could be a thermostat problem, ie it could be stuck, and is telling the radiator to get rid of water. Does this make sense?
Thanks for any help.

GavinPJQuinn

What car is it?

awishawash

Hey Gavin, its an auto mitshbishi pajero jeep. left it in to have the problem fixed and for a service before Christmas, got charged an arm and a leg and the problem was back next day. Aswell as a whistling out of it when its stationary and I give it throttle. I thought it was brakes as these were replaced but no. Wtf did they do to it. And yes I paid cash and got no receipt.

AMurphy

Check for leaks with the engine hot and running. A leak could be anywhere, including the heater piping, waterpump shaft.
If the thermostat was sticking, it would not wait 4 days to show up, that's immediate.
However, you may have a low rad cap pressure, so loosing pressure there, especially after stopping and when you are not there to see anything. Easy to replace or pressure test both Thermostat and rad cap.
And it could also be a head Gasket. Any surplus steam in the exhaust.

Anotehr vague possibility, if it is an automatic and has a ATF cooler in the Radiator, which has developed a crack, you could have water in the gearbox, oil in the coolant or both. Check your tranny fluid also.

awishawash

Thanks for the help Al, will check tonight about the noise. Is the rad cap just the cap you open at the top?Dumb question i know. What do u mean low pressure, as in its seals arent tight? Its letting water out - in steam or bubbling - when hot?
Is the head gasket a major job? I'm about to trade this yoke, just my luck if it was the head gasket gone.
How would I check for water on the gearbox. Its automatic but I notice mainly with the problem it wont engage into gear when the temp gauge is up the top and I turn the engine off and can hear the overflow coolant thingy bubbling hard. Then it cools down and I put more water in and she drives again until the rad is empty again I suppose.

AMurphy

the cap is on the top of the radiator, usually.
It has a pressure and venting valve built into it. If these valves/springs fail you would change the intermal rad pressure and with it the boiling point of the coolant.
If in doubt, just chage it, cannot be more than $20 for a generic replacement from a Motor Factor.
Dont remove the cap until the engine is cool or cold.

Head Gasket change is generally a major pain.

Most modern automatics are designed to detect overheating and shut down or put the A/T into Limp Mode, to prevent further overheating.

You should have a dipstick for the Auto Trans Fluid, after you do a run, pull out the dipsitck and examine the oil it would be eitehr red, wine, dark brown, and have no white, grey, foam, etc on it. may smell. How many miles on the Oil and anyway, only of consequences if you have an ATF cooler in the Rad.
Many have Oil to Air coolers, so not an issue there.

awishawash

Cant figure this thing out at all. The whistling(well a boreing, droning whistling)sound is gone today just as I found the time to test it. However, when I was driving along it began to break down again, the temp gauge rose up to the Hottest mark and she lost power, then after a few seconds the needle went back to normal and it drove away grand. What the fock is going on.

AMurphy

Take out your thermostat and check it.

Whistling-boring sound. Something rotary I would guess.

Few possibilities.
Your belts are loose, the belts are OK, but the water pump shaft or impeller is not rotating, and thus not circulating the water, hence you are getting a hot spot and boiling.

Does this have a rad fan that is driven directly off the engine or an electric setup?
If driven off the engine pulleys (with maybe the water pump behind it).
Check the fan is rotating OK. It may also have a thermal clutch, which is not working, so it may be rotating, but slipping badly when needed.
Check it out.

Check your radiator is not obstructed with dirt, paper, etc, thus air is not flowing through it.
Next time this begins to happen, i.e. the needle rises from normal, turn on the cabin heater and fan to max, see if it cools it down. If the cabin air is not warm, you have an airlock in the heater, or no coolant or no flow, or all the above.

Also, check your radiator for hot and cold spots. Easier to do with an Infra Red thermometer, but, you could use your hand also... be careful.

Start up and run the engine, monitor the radiator as it heats up. Check that all parts are heating. If you have one very hot spot and one very sold spot, means you have plugged cores, this will also lead to overheating as you describe.

And if this thing has an electric fan make sure it is working. Warm up the engine, shut off the heater and let it sit idling, with all the electrics on to MAX, to load the engine. The fan should switch on and off about every 10 min or so. If not, short the switch and see if the fan is dead or alive.