Thread: Puma Defender Air. Cond. Engine fan/ noise?

Pickles,

My needle never moves, but the Ultra Gauge shows fluctuations between 83 and 92 degrees all the time. My fan kicks in at 88 which is pretty much all the time when the ambient temps are hot enough to warrant the aircon, which is pretty often in WA!

I don't think there is much or anything in fact to worry about.

Might be worth investing in a Ultra Gauge as its a small investment for a lot of piece of mind. The plug just lives in the OBDII port under the steering wheel and there is many ways to mount the screen unobtrusively.

UltraGauge OBDII Scan tool & Information Center

Cheers,

Lou

What fan are you talking about,the A/C fan or engine?.The A/C fan always runs when the A/C is on,the engine fan on mine can't be heard but I can feel it on hot days because the motor is sluggish to rev.I have a scan guage mounted on the steering column and mine goes to 96 degree's towing in Pilbara heat,88-90 around town normally. Pat

If you're talking about the electric fan then it really has nothing to do with engine cooling. Its purely there to cool the aircon condenser.

However I have heard that it also runs when the engine is getting towards dangerously high temperature. I'll repeat that this is just what ive "heard".

Otherwise it just works of a high-side pressure signal. When the pressure in the condenser is above a certain point, the fan will cut in to cool the condenser and bring the pressure down.
Things that cause high condenser pressure are high ambient temps. and high heat loads being absorbed from the cabin.

I've also noticed that it doesn't take much for the condenser fan to kick in on my 130.

Hope this makes sense to you?

Tom

Originally Posted by Beery

If you're talking about the electric fan then it really has nothing to do with engine cooling. Its purely there to cool the aircon condenser.

However I have heard that it also runs when the engine is getting towards dangerously high temperature. I'll repeat that this is just what ive "heard".

Otherwise it just works of a high-side pressure signal. When the pressure in the condenser is above a certain point, the fan will cut in to cool the condenser and bring the pressure down.
Things that cause high condenser pressure are high ambient temps. and high heat loads being absorbed from the cabin.

I've also noticed that it doesn't take much for the condenser fan to kick in on my 130.

Hope this makes sense to you?

Tom

Yes, I think it does.
What you're saying is that the condenser fan in front of the radiator, visible behind the grill is on for most of the time when the A/C is on?
When I notice it, is maybe after a few ks and then you enter a town, & as you change gears, change down etc, you can hear more fan noise, signifying to me that the elec fan is on.
On other cars that I've owned, the "auxilliary" fan wasn't "connected" at all to the A/C system, ...it simply came on when the engine was over a certain temp, whether the A/C was on or not. As the fan on these engines was usually enough to cool the engine in almost all conditions, the elec fan hardly ever came on, which does not appear to be the case with the Defender.
Pickles.

You might actually be hearing the radiator fan by the sound of that. The condenser fan on the puma's is actually pretty quiet after listening to mine.

If you hear it roaring when you're going down the gears and changing pitch as the revs change then its the belt driven fan.

Coming into town and slowing down from highway speed where you've had the engine under load, you suddenly lose a lot of airflow through the radiator. The radiator is still getting rid of that highway heat and with less airflow, the air going through to the viscous fan hub will be hotter, causing it to lock up and drive the fan.

Its a thermatic fan that runs on a hi pressure switch to lower the discharge pressure on the air cond. It helps to cool the superheated vapour from the compressor and if it doesnt run you wont get the correct pressure drop into the evaporator for cooling effect. It will cycle on and off as required so its quite normal. If it doesnt run with the air cond then you have a problem, especially this time of year.
cheers Ian

Pickles,your other cars may have had one or two electric fans behind the radiator that run together and cycle to keep the coolant temps within parameters.They are often very quiet.
These fans also run when the A/C is on,and cycle on and off with the A/C thermostat,with an override to run if needed to keep coolant temps correct.

With the defender it has a large belt driven viscous fan behind the radiator that cycles to keep coolant temps correct.You can sometimes hear it cycling.It also has an electric fan in front of the condenser,that pushes air over the A/C condenser and then the radiator.This electric fan operates when the A/C is on.

Originally Posted by Pickles2

Yes, I think it does.
What you're saying is that the condenser fan in front of the radiator, visible behind the grill is on for most of the time when the A/C is on?
When I notice it, is maybe after a few ks and then you enter a town, & as you change gears, change down etc, you can hear more fan noise, signifying to me that the elec fan is on.
On other cars that I've owned, the "auxilliary" fan wasn't "connected" at all to the A/C system, ...it simply came on when the engine was over a certain temp, whether the A/C was on or not. As the fan on these engines was usually enough to cool the engine in almost all conditions, the elec fan hardly ever came on, which does not appear to be the case with the Defender.
Pickles.

Pickles,

The big noisy fan in the front is the engine is just your radiator fan that has a set temperature to switch on. It's pretty noisy as the Defender's bonnet is hardly sound proof. It will cycle on and off randomly when the car is idling regardless if the aircon is on.

To my knowledge it has no direct link to the aircon and it is most probably coincidence of matching high ambient temperatures that "keeps it running" when the aircon is on.

Cheers,

Lou