I have been reading everything here about the cooling fan on Discovery's but I can't quite find an answer to my problems.

My 2004 Discovery cooling fan, for the AC, is running on and off in very cold weather. The AC is off and it's still doing it.

Today I went to warm up the disco as it was -23c (-9F) and after 10 minutes of it running the Cooling Fan was running. This happens off an on while driving it. The temperature gauge on the dash never reads higher than the middle marking at anytime while the cooling fan is running. If a temperature sensor is gone and the cooling fan was coming on due to overheating, would the inside temperature gauge not rise also?

I have noticed some sort of coolant leak on the passenger side of the engine about mid way up, or closer to the head gasket but I have no pin pointed exactly where yet.

I am also having some problems with the secondary air howling on and off while driving or at red light. I replaced the solenoid valve for this but this has not helped. I also secured all air hose connections with tie straps as I had read in other posts. Do any secondary air problems ever cause cooling fan issues?

My mechanic does not see why the cooling fan should be on unless the AC is turned on. I think this has been this way for some time and if it has been, what damages am I doing, or what else should I be looking for now?

The water pump was changed late summer and the thermostat just before.

Any advice would be great, I am lost and obviously so is my mechanic.

Thanks.

 

Does not sound as though you have a ultra gauge???? Basically electric fan is set up to come on When your truck temp hits 212° boiling. So you have a problem that if you do not get resolved is going to cost you a engine. I would park the truck and figure out what's wrong with the cooling system.
The inside gauge sucks and that's been stated too many times. Your coolant leak is probably the reaso. Tgat this fan is trying to save your truck although it may already be to late.
And another thing is if you have not replaced your front drive shaft now is the time. They fail and cause big problems


Secondary air and your cooling not related.

GET A NEW MECHANIC THIS ONE IS NO GOOD FOR ROVERS


I suggest you do a pressure test but you already know where this leak is now you need to fix it.


STOP DRIVING IT.

 

lr2001silver -

Thanks for the information, I appreciate it. I have a feeling this has been going on longer than I have realized and due to my mechanic telling me that it was not an issue, what sort of damage might be happening?

The leak I have, on the passenger side closer to the front, could that possibly be the temperature sensor leaking, is it in that same area? Could it be the temperature sensor that is causing the problem or them thermostat, both or something other?

 

Find someone with a scanner that will give you real time information, watch the temp as you drive and lets us know what the temps are.
Yes, you can be causing damage, if you want some help send me your number and ai'll call and walk you thru what to do.

 

Damage could be warping the heads or worse the block.
You need to find the leak and fix it asap and rovers leak oil and that's pretty common however any coolant leaks need to addressed as soon as they are noticed because if not you will end up with serious problems.

Leaks may be a faulty thermostat or a faulty hose?
Let Mike help you out as I am in meetings all day.
He will go over some places for you to check and some fixes.

 

Disco Mike - I will arrange to get my Disco hooked up to a scanner to get the temperatures as you suggest. Once I have these numbers I will let you know. What are the correct temperatures that I should be showing for the 4.6l engine? Thanks for you time Mike.

lr2001silver - thanks again for taking the time to respond to me. The head gasket has not been done on this yet and I now have 105,000 miles on it so I am thinking about either doing the work on this engine or possibly bringing over a remanufacturer block, heads, etc out of the UK if my finances will allow... can't count on that though.

Any thoughts on whether to rebuild what I have vs bringing over a long block?

I love the Disco and obviously am tired if dumping money into it so I want to do things right so it will last me another 105,000 miles!

 

The a/c comes on when the defrost is on.

 

There is a good point also.

 

For what a shop will charge you, you could go out and buy your on scanner and quit depending on the shops. For a little over $100 you can buy your own scanner with real time.

 

Mike - I know a guy with a big fancy Snap On scanner who does not charge me to hook up my Disco... not yet anyways! Are you suggesting the ScanGauge type of scanners? Can you recommend one that works well with the Discovery?

Jafir and Mike - I never use the dedicated defrost button, I only use the vent selection button to put the heat up to the windshield. I know the defrost button turns on the A/C which in turn obviously turns on the cooling fan so... I only wish that is what is was! A couple of weeks ago I was driving with the ECON button off, so yes I was driving with the a/c on and the cooling fan at the same time.

When I drive around, the cooling fan is not on at all times, more so when at an idle and even then it's not all the time and right now we are in a cold snap as I first mentioned, -23c / -9f.