overheating when driving slow

Hi, im new to this site as i only got my range rover a couple of weeks ago, number of minor problems that need sorting, the main one though is it has started to overheat a couple of days ago, but only when driving slow as soon as i get on the motorway it sorts itself out and runs quite well. I was advised that the viscous fan could be at fault, just went out to check that and realised the the fan is stuck on full power as soon as i start the engine.
can anyone give me advice and point me in the right direction

oh forgot to say, its a 2.5 dhse 2000 plate auto

ash_g said:

oh forgot to say, its a 2.5 dhse 2000 plate auto

Click to expand...

The first minute or so after starting the viscous fan will be on full power until the silicone liquid frees up, it should then back off until the temperature rises. To check, stuff a rolled up newspaper into the blades with the engine hot (mind your hands) if the fan stops it's stuffed. I can give you a mod to use the aircon fans either as back up or to replace the Viscous fan.

Datatek said:

The first minute or so after starting the viscous fan will be on full power until the silicone liquid frees up, it should then back off until the temperature rises. To check, stuff a rolled up newspaper into the blades with the engine hot (mind your hands) if the fan stops it's stuffed. I can give you a mod to use the aircon fans either as back up or to replace the Viscous fan.

Click to expand...

hi could you explane more about the viscous fan and how it works i thought it was powered off the drive belt alone:doh:. and is it the same for diesel and petrol models thanks.

thanks for the advice, i was thinking that if the fan was locked up from the start then that would mean it was knackered too, it sounds like a jet at the minute. The mod that you are talking about, is that better than the viscous fan?

fix it said:

hi could you explane more about the viscous fan and how it works i thought it was powered off the drive belt alone:doh:. and is it the same for diesel and petrol models thanks.

Click to expand...

The body of the fan is powered by the belt, drive is transfered to the fan blades via the viscous coupling. This is an enclosed system of vanes connected only by a silicone liquid. The angle of the vanes is adjustable via the bi-metalic strip on the front of the fan. As the strip heats it increases the angle of attack of the vanes therebye giving more drive to the vanes. When totaly cold, the blades will run at full speed until the silicone liquid warms slightly. Petrol and diesel are the same in principle, but the actual fan may be different

ash_g said:

thanks for the advice, i was thinking that if the fan was locked up from the start then that would mean it was knackered too, it sounds like a jet at the minute. The mod that you are talking about, is that better than the viscous fan?

Click to expand...

The key to whether the fan is knackered is if it can be stopped when the engine is hot. A siezed fan viscous coupling will not cause overheating, just a slower warm up.
The electric fans can be used instead of the viscous fan on the diesel or as extra cooling. PM me with an email address if you want details.

Datatek said:

The body of the fan is powered by the belt, drive is transfered to the fan blades via the viscous coupling. This is an enclosed system of vanes connected only by a silicone liquid. The angle of the vanes is adjustable via the bi-metalic strip on the front of the fan. As the strip heats it increases the angle of attack of the vanes therebye giving more drive to the vanes. When totaly cold, the blades will run at full speed until the silicone liquid warms slightly. Petrol and diesel are the same in principle, but the actual fan may be different

Click to expand...

Thanks matey could solve my overheating issues.