It is 37f outside, when I start up the lr the cooling fan comes on. I had it at idle for about 7 mintues and the cooling fan stayed on the whole time. Is this normal? Also, temp gauge never moved. I don't have an ultra gauge just yet.
Smelled some coolant yesterday after a short drive, but I didnt smell it today when it was in idle.

Any help?

 

The electric fan is supposed to come on at various conditions, from the spec page in shop manual:



⇒

 

I had O'Reily Auto run a scanner on it. All they found was code 1590 which is rough road sensor. I did smell coolant again after I drove it about 10min round trip. Guess I will have to get a pressure tester and look for leak...tried looking for leak last night with flashlight and this morning but couldnt' see anything

 

agree on the leak test, but that is not what is keeping the fan running, unless the coolant sensor is telling the ECU it is 212F when first cranked up - maybe skinned wire or connector

 

Savanah -

Do you know where the coolant sensor connects to from the radiator on a 2004 Discovery?

 

on the fan running all the time - try spinning fan when off, it should turn very freely, no load. The relay could be "spot welded" closed because the fan was drawing too many amps.

on the themostat monitoring sensor, it is at the passenger side of rad near bottom, see attached. It senses if main thermostat is stuck open. The coolant temp sensor is between the alternator and AC compressor on top of the intake. It eventually gets to the ECM on pins 5 and 21 of connector 635, wire color is black with green, and slate (gray) with green.

 

Savanah, When you say "See attached" what were you refering to?

Also, I was reading on your "cooling system problem" that a clutch fan that was not stored in a vertical positon before install can create some problems -What sort of problems and how would one know if it is not working properly after installation? If not working properly after install, would the issues be the same as what was mentioned above and in other posts - no resistence when turning the fan after sitting all night, etc? I just looked at my old fan clutch, to which is the same as the new one I put on, and around the metal coil it says to store that side down. Now I am worried I may have wrecked a new fan clutch. I have lots of resistence before starting it in the morning but no "roar" when first starting it which my old on did not have either but the old did not have complete resistence when turning it - had some resistence for 1/4 turn then went loose for 3/4 turn before returning to some resistence and repeated.

I just replaced my fan clutch, it was not vertical before install, was shipped to me horizontally (laying flat in the box). With the new fan clutch I do not get the "roar" when starting, Is this temperature dependant? It's been quite cold here in Canada for the last couple of weeks but the next few days a warming up so I am hoping to hear the roar. Mine is the one piece assembly (fan clutch and blades all one piece) for a 2004 Discovery.

As I said in my other thread, I am still chasing my cooling fan issue of it running in cold weather on and off. The AC / Defrost is off, have lots of cabin heat and no I don't have the ultra gauge!

Thanks.

 

My attachment fell off, it is back now. As for fan storage, you can't possibly think that a small carton will always travel in one orientation in modern logistics. Now a full jumbo case of them, strapped to a pallet, that is a different matter (most of the time).

I look at it this way, like freon in a fridge. The unit needs to be in the orientation for operation for maybe a day before putting power on it. This lets liquid settle to where it was engineered to be when system was not operating, but ready to switch on.

I think the OP is talking about his electric fan.

Now on the viscous fan, the design with two halves of the clutch separated by a small space, and concentric circles of grooves inside, the viscous fluid when pooled to one side makes both halves couple at maximum power transfer. Clutch starts spinning, and fluid is spread out, coupling decreases and roar goes away. On a clutch with a valve, the valve may have to reach a certain faceplate temperature before that coupling starts to return. Usually on the order of 150F - 190F (not air temp, but actual fins on the clutch temp). So if in a very cold place, with wind chill, it would seem unlikely that the fan clutch would couple to full power. Also, if a radiator is sludged up a good bit, there is less heat coming off the rows at the center where the clutch airflow is and the clutch won't operate.

Of course, main thing is for clutch no to freewheel warm or cold. Low power coupling is about 20% power, so it can still take your finger off; higher power is 70% or higher depending on clutch design. Some clutches are also designed to decouple at higher RPM (like 6000), I guess on my Mercedes engineers figured if you have pedal to the metal on the Autobahn the fan should not be turning so fast that balance can tear it apart.

 

Savanah -

Thanks for re-attaching the diagram for the temp. sensor on a D2.

I do realize that the origianl OP was talking about the cooling fan and I have a thread with much of the same problem. The adivice was to check / replace everything from T-stat to fan clutch, to possible head gasket leak and since I just replaced the fan clutch I thought I would bring up my experiences in this problem to date so they can read about it as it might help.

I have to tell you I lost sleep last night in regards to my fan clutch. If it was not stored properly before installation, if it is now not operating as it should, will it more than likely just spin freely or how will I be able to tell if it's not working properly? I am well aware of the resistence when turning it by hand and I do have that. It will spin maybe 2-3 inches before stopping. I don't have the roar although when I installed it onto the warm engine I did get a small roar when I started it after it was installed but since then nothing but it's been cold as I said.

MY cooling fan still comes on when idling though so the journey continues. I will install a new t-stat tomorrow. If the temp sensor was not reading properly would it throw a code?

Thanks so much for your time.

 

Sounds like you clutch is OK because it is smooth and does not freewheel. The rad temp sensor is supposed to throw a code that indicates the thermsotat is stuck open (too much cooling).