Sprinter Viscous Fan Running Continuously

[ringway]

The viscous fan on my 2001 213CDI Sprinter is running full time when the engine is on.

This would cost around £400 to replace including labour.

Is there any point in me trying to disable the fan and if so would it be safe to do so?

I did experience a temporary drop in power yesterday and wondered if there was possibly a connection between this and the fan running full time.

I took the van to my MB commercial specialist this evening and the power drop did register on their star diagnostics, but they were at a loss to identify the problem (could be a hose, turbo.......).

Before I left the van was road tested and the turbo registered as functioning correctly.

Any advice, as ever, is always appreciated.

 

[grober]

Price seems a bit over the top unless the fan is very difficult to reach. A viscous coupling SACHS http://webcat.zf-trading.com/index.asp?LKZ=D&PKW=1&SPR=4&EINSPNR=32,14,1632,1614 shouldn't be too expensive. Of course if the fan is running because the engine is running hot that could lots of things- first stop would be radiators.
Another thought---- the fan will "appear" to run all the time but may simply be freewheeling until the clutch engages--you will know this because its quite noisy when "driven" (think large desktop fan on full)

 

[ringway]

Price seems a bit over the top unless the fan is very difficult to reach. A viscous coupling SACHS http://webcat.zf-trading.com/index.asp?LKZ=D&PKW=1&SPR=4&EINSPNR=32,14,1632,1614 shouldn't be too expensive. Of course if the fan is running because the engine is running hot that could lots of things- first stop would be radiators.
Another thought---- the fan will "appear" to run all the time but may simply be freewheeling until the clutch engages--you will know this because its quite noisy when "driven" (think large desktop fan on full)

Thanks Graeme,

Price quoted was £137.00 for the part (excluding the actual fan) and 2-3 hours labour all plus VAT = around £400.00.

I recall the fan used to come on on very hot days, but now is in use all the time. The van now sounds like a wind machine..

A new thermostat was fitted recently, could this have any bearing on matters?

Regards,

Paul.

 

[grober]

Normally these viscous clutches work by the bimetal strip on the front reacting to the temperature of the air. These clutches should only stored in a vertical position to prevent fluid migrating to places it shouldn't. Its possible that something happened to it while the thermostat was being changed I suppose causing it to remain on all the time. A faulty thermostat could be causing the engine to run hot I guess so several possibilities sources of your problem there. Once the van engine has warmed up check that the radiator top hose is hot showing the thermostat is open.

 

[ringway]

Normally these viscous clutches work by the bimetal strip on the front reacting to the temperature of the air. These clutches should only stored in a vertical position to prevent fluid migrating to places it shouldn't. Its possible that something happened to it while the thermostat was being changed I suppose causing it to remain on all the time. A faulty thermostat could be causing the engine to run hot I guess so several possibilities sources of your problem there. Once the van engine has warmed up check that the radiator top hose is hot showing the thermostat is open.

Checked the top hose with engine warm and it is not hot.
The heater blows very hot if you need it though.

 

[grober]

It sounds as if the new thermostat is faulty and not opening. The heater circuit is normally taken directly from the block/cylinder head and returns to the pump inlet and would be unaffected by a thermostat fault. I would take it back to whoever replaced the thermostat and get them to check it out and replace if faulty.

 

[ringway]

It sounds as if the new thermostat is faulty and not opening. The heater circuit is normally taken directly from the block/cylinder head and returns to the pump inlet and would be unaffected by a thermostat fault. I would take it back to whoever replaced the thermostat and get them to check it out and replace if faulty.

Many Thanks Graeme.