I have a 1998 600 f3 and the coolant is bubbling and the fan isant turning on.. it over heats in fifteen minutes..does anyone no what it could be .. a diagnostic is 100 bucks so just trying to fix it myself!!!

check coolant level fan operation and water pump

Hi Fred.

I'm not totally sure I understand your question, but I'll take a shot. Are you saying that the engine fan stays on all the time for your car, keeping the radiator cool, and so you're not able to get any heat in the cabin air? Or possibly that the cabin fan is on all the time and you can't get any heat because it's keeping the radiator cool.

unless there is something very odd about your car (or you're living at the south pole), your engine coolant will be plenty warm within a few minutes of starting. If you are doubtful, drive the car for 5 to 10 minutes, stop, turn off the motor, pop the hood, and carefully move your hand close to the radiator. The blower fan helps transfer heat, but that's to move the coolant temp down probably into the 150-200F range.

if you're not getting any cabin heat, I'd have stronger suspicion about the heater core for your air system. In the majority of vehicles, there is a loop of coolant that comes off the back of the engine block, through the fire wall, and up to a U-Bend of pipe. When the heater is off, the coolant is just re-directed back to the engine. As you turn the knob or lever for cabin heat, it'll turn a switching valve to shunt the hot coolant into a heat exchanger/mini-radiator that the cabin air blows past. This system being a mini-radiator is why highways with long uphill grades will advise motorists to turn on their heater full heat, highest fan, when climbing in the summer. it's an additional way to keep the engine from overheating, even if it sucks for people in the vehicle.

Depending on the car, it can be either easy or really involved diagnosing or repairing the heat exchanger. if you go this route, you'll want to make sure that the coolant is circulated through the core thoroughly and that the coolant-system is de-bubbled.

Good Luck!
D

change the coolant sensore and check the fan is working or no and also check for reverse spin of your fan the fan moving facing to engine not going to out from engine

where is it leaking from? is it low in water from leaking? there is a hole on top of your water pump if the seals go bad in it thenit will leak water till the piont thatit gets low and cause heating.check for location and let me know.last thing you want to say is blown headgasket

When the car is completely cool,check the electric fan(s) for smooth rotation.

Clean/check/change the thermo sensor,contact and wire.

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Excavate air pocket in coolant system / check for head gasket leak

This test will kill two birds with one stone.

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MAKE SURE THE COOLANT SYSTEM and ENGINE IS COLD!

RAN THIS TEST IN A WELL VENTILATED AREA ONLY!

You will spill some coolant during this air pocket purge test.......BE KIND TO THE ENVIRONMENT and ANIMAL please clean up after the test!

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Put the front end on a pair of ramp or park your car on a VERY STEEP HILL (radiator facing top of the hill) .

Top of the coolant reserve tank

Let it ran for 10-15 minutes.

Monitor for air pockets escaping from coolant reserve tank.

Small amount of bubbles is OK at 1-5 minute mark

After the thermostat open up (after 195 F warm up) at
5-12 minute mark or after high idle you should see less bubbles.

If you do not see any in rush of bubbles then your thermostat may be partially stuck or rusted badly inside the thermostat hosing.

Give the thermostat host few gentle taps.

If you see larger bubbles surfacing after 15 minutes then should do a hydrocarbon (HC) dye test to test for potential head gasket leak.

Let engine cold down and top off coolant reserve tank.

Start monitor for coolant lost

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A coolant flush is require every 2 years or 24,000 miles.

I recommend the thermostat that has a relief pop-let to reduce the change of burst radiator and coolant hoses.

Make sure you get a new thermostat gasket,black RTV and fresh coolant for the job.

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Have you found the reason for the overheating? Other than a stuck-closed thermostat, maybe the fans were not working before. First suspect for the fan problem is the thermal sensor located near the thermostat housing on the engine. Try turning on the A/C system--that should start both fans immediately. If they do, that eliminates the fans, relay, fuse, and computer. If they don't come on, check that both fans turn freely and check the fan fuse in the fuse compartment. The relay is a solid state device that should be located near the fans on the driver's side. If the relay has a browned look, it is probably fried. Make sure to blow out the radiator core with compressed air (from the engine side) to get rid of collected bugs and other debris. Hope this helps track down the problem.

Very common fault is head gaskets.  causing coolant consumption and bubbles in radiator.  Run vehicle, have a friend accelerate once or twice hard, while you smell exhaust for sweet smell of burning coolant.

Fifteen minutes! you have bigger problems than only the fans the fans are controlled by a thermo switch that is heated by the coolant, If you have no coolant the sensor cannot activate But fifteen minutes seems like you may have a headgasket problem and steam cannot heat the coolant sensor.OperationNotesThe electric cooling fan operates when the engine cooling temperature exceeds a certain value. The cooling fan on this engine is controlled by the Powertrain Control Module (PCM) . The PCM turns the cooling fan ON by grounding the coil of the cooling fan relays when certain conditions are met. When the A/C is requested, the cooling fan will also be turned ON.

Power for the cooling fan motors are supplied through Maxifuses(R). The cooling fan relays are energized when current flows from the fuses in the Underhood Accessory Wiring Junction Block, and through the relay coils to ground through the PCM. The Coolant Fan 1 Relay Control Circuit is grounded for low speed fans operation. During low speed fans operation, both fans run at a slow speed. The Coolant Fan 1 Relay Control Circuit is grounded for high speed operation. During high speed fans operation, both fans run at high speed.

IMPORTANT: When certain Diagnostic Trouble Codes (DTCs) are present, the PCM may command the cooling fans to run all the time. Perform the A Powertrain On Board Diagnostic (OBD) System Check prior to diagnosing the engine cooling fans.

For more information regarding the Charging System, refer to Charging System Description , and Charging System Circuit Description in Starting and Charging.

If a problem that involves the low speed cooling fan relay control circuit exists, DTC P0480 Cooling Fan Relay 1 Control Circuit should set. If the problem affects the high speed cooling fan relay control circuit, DTC P0481 Cooling Fan Relay 2 Control Circuit should set. A problem with the ECT sensor should set DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage, DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage, DTC P1114 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage, DTC P1115 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage. Any of these DTCs will affect cooling fan operation and should be diagnosed before using the Electric Cooling Fan Diagnosis.

For more information regarding the Cooling System refer to Engine Cooling Fan Description - Electric, and Cooling System Description in Cooling System.


Here is the electrical schematic and how it all is suppose to work,
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You need to verify that the gage is accurate, if it is then the cause is the thermostat, but check the gage first, a repair shop can do this or you can feel the air coming off the radiator fan, if it is really hot changing to cool rapidly then the T-Stat is sticking open.