overheating problem at idle

[DariuszZ]

Hey,
I have an overheating problem with my motor. When at idle, the fan wont turn on in order to cool the radiator BUT if i turn off my car, the fan will start working right away until its cool again. Im not sure why this is happening.
Thanks in advance

[Fleetw00d]

What specifically is happening at idle that you say it is overheating? The temperature gage rises slowly? Quickly? Drops quickly when you accelerate (or even just speed the engine up in neutral)? Coolant boiling over into the overflow tank?

[UnderPaidSlave]

My cars fan always runs after I shut the car off. I thought it was normal... the needle raising when its idling if that's what's happening... Its probably a sticky thermostat, but like the guy above said were gonna need more info..

[99CcordMTF23]

Change everything that it could possibly be. Water pump, and change your timing belt too, then change your thermostat. Maybe the fan switches and relay. make sure there isnt air in the cooling system, ect. Not that big a deal.

[Fleetw00d]

Change everything that it could possibly be. Water pump, and change your timing belt too, then change your thermostat. Maybe the fan switches and relay. make sure there isnt air in the cooling system, ect. Not that big a deal.

Shotgunning can be an expensive way to fix a problem, particularly if you're telling him to do the timing belt and water pump first. A little diagnosis goes a long way. Describe the symptoms in more detail, recent service completed, etc. Check coolant level in the radiator when cold (should be full to the top). Is it pushing coolant out of the overflow tank? Fans coming on after shut down is normal, mine almost never come on when I'm driving unless in stop and go.

[CBro7]

Yep, the fan is normal. And blowing money on things it could possibly be is a really bad idea. Your water pump and timing belt are probably fine. There could be an issue with the fan system, but I think when you're moving the car would run about as hot because even though it's getting more air circulating around the engine, it's working harder. And the fans are still working.

[DariuszZ]

h22 swap,
Brand new thermostat water pump timing belt, flushed coolant so there is no air inside. After 4 minutes when sitting at idle the needle goes up, thats when the fan should kick in, it doesnt. When i turn off my car i can hear the fan working.
And of course it drops when i accelerate and get some air.
Any ideas?

I remember my friends cb7 overheating problem. Reving up in neutral would bring the temp down. This is not my case though

PS
Sorry for the long reply, i was busy working :S

[UnderPaidSlave]

Maybe your new motor just runs alittle warmer than the old one. Its probably something dumb air buble in the cooling system bad radiator cap. Hard to say really.

[DariuszZ]

the fan, should turn on, after a while if the car is not moving. so that they will cool the radiator. Im just wondering if there is like a coolant temp sensor that might be busted or something?

[UnderPaidSlave]

If I remember right you say the fan turns on when the car is off. That would make me think the sensor is alright.

[jay92889]

Hey,
I have an overheating problem with my motor. When at idle, the fan wont turn on in order to cool the radiator BUT if i turn off my car, the fan will start working right away until its cool again. Im not sure why this is happening.
Thanks in advance

I just wrote the same thing in another thread but it is either your thermoswitch or your fan timer.. with the car running jump the harness that is for the sensor that is in the thermostat housing. Do the fans come on? If both don't come on, leave it jumped and try switching the cooling fan relay with the power window relay in the fusebox. If that doesn't make any change, it is more than likely your fan timer box located under the dash. I just had this issue and completely diagnosed the whole system with a meter. Exact same issue, it was the fan timer Unit.

[mozzandherb]

is your radiator overflowing at all?

[accordztech]

Change everything that it could possibly be. Water pump, and change your timing belt too, then change your thermostat. Maybe the fan switches and relay. make sure there isnt air in the cooling system, ect. Not that big a deal.

Are you serious?

Shotgunning can be an expensive way to fix a problem, particularly if you're telling him to do the timing belt and water pump first. A little diagnosis goes a long way. .

Damn right.

Ok first rule out your thermostat. 5 minutes at idle wont be enough to over heat the car if its fan related. With the car warmed up, feel the upper and lower hoses, they should be the same if not near similar. If not then its the thermostat.

I dont care if it was changed already, its a quick check. I seen a few go bad asap.

Flushing the cooling system doesnt take out air, bleeding it takes out air. Open the air relief valve to see if there is a steady stream of coolant comming out, no air.

There are detailed instructions in the FSM to test the fan timers. Look it up.

Good luck. Never assume, nor waste money.

[phantomcow2]

Change everything that it could possibly be. Water pump, and change your timing belt too, then change your thermostat. Maybe the fan switches and relay. make sure there isnt air in the cooling system, ect. Not that big a deal.

Is this a joke?

[Noridetoolow]

Change everything that it could possibly be. Water pump, and change your timing belt too, then change your thermostat. Maybe the fan switches and relay. make sure there isnt air in the cooling system, ect. Not that big a deal.

If he has money to do this every time something minor breaks....he wouldnt be driving a 20 year old car.

Ive never heard of the fan timer issue before but your problem is pretty unique and specific so I think this sounds like a very possible fix. Typically the fan either works or doesnt, ignition on or off.