Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: bp_porcaro on 14 December 2009, 09:22:32

Title: Running 2.5td without viscous fan?
Post by: bp_porcaro on 14 December 2009, 09:22:32
Can the 2.5td run ok without the viscous fan during the winter ????

Will it help get to running temp quicker for short morning journeys ? and hence probably give better mpg.

Any advice or experiences would be gratefull.
Title: Re: Running 2.5td without viscous fan?
Post by: Kevin Wood on 14 December 2009, 09:53:43
I believe TheBoy ditched the viscous fan on his and it worked fine in all weathers.

.. but it won't help it warm up quicker because it's only when the thermostat opens that it provides any cooling effect (assuming everything is working as it should).

It will probably quieten the car down a little and save a little fuel though.

Kevin
Title: Re: Running 2.5td without viscous fan?
Post by: damage consultant on 14 December 2009, 11:15:07
I took mine out after i recharged the air-con this is left on as a back up if I get stuck in traffic.
it doesn't sound like a jet taking off now ;D
Title: Re: Running 2.5td without viscous fan?
Post by: Turk on 14 December 2009, 16:18:20
Mines been off and stored upright with the spare wheel for about 6 months.
I kinda miss the "Whoooosh" sound, but it did break all else.
Title: Re: Running 2.5td without viscous fan?
Post by: platty on 14 December 2009, 19:03:17
If you throw the viscous in the bin it may warm up slightly quicker (only very slightly) but the most likely candidate will be the thermostat.
Title: Re: Running 2.5td without viscous fan?
Post by: charlie on 14 December 2009, 19:04:54
with out the fan on i can do 1200miles journry in 20 hours no problem
Title: Re: Running 2.5td without viscous fan?
Post by: charlie on 14 December 2009, 19:05:38
with overheating
Title: Re: Running 2.5td without viscous fan?
Post by: bp_porcaro on 14 December 2009, 19:09:34
I take it you meant 'without overheating'  ;)

I've read enough  :y it's coming off at the w/e.

Cheers everyone.
Title: Re: Running 2.5td without viscous fan?
Post by: charlie on 14 December 2009, 19:12:29
yip thats what i meant :-X
Title: Re: Running 2.5td without viscous fan?
Post by: TheBoy on 14 December 2009, 20:18:59
Yeah, ran mine for 18months with no viscous. Chipped, and not exactly driven like Miss Daisy.

Change the stat though, yours is shagged. Once viscous off, about 20 mins to do stat (reckon I could do in under 5)
Title: Re: Running 2.5td without viscous fan?
Post by: Lazydocker on 14 December 2009, 21:17:34
Quote
Yeah, ran mine for 18months with no viscous. Chipped, and not exactly driven like Miss Daisy.

Change the stat though, yours is shagged. Once viscous off, about 20 mins to do stat (reckon I could do in under 5)

TB wins the prize for understatement of the day ::) ::) ;D ;D ;D
Title: Re: Running 2.5td without viscous fan?
Post by: chartz on 09 January 2010, 22:23:00
Hi,

Well I never could run without my viscous fan. But then I found out that an obstructed (they all are) aircon radiator prevents the air flow to reach the clutch, hence never disengaging the thing, unless the weather is very cold...
The solution is to interpose some plastic sheet between the two radiators and karchering out the mud and bugs that have invariably accumulated there through the years.
Title: Re: Running 2.5td without viscous fan?
Post by: bp_porcaro on 10 January 2010, 13:51:24
I took the viscous fan off about 3 weeks ago, and replaced the stat at the same time.

It runs perfect now.  Gets up to about 80 quicker and then holds steady at that temp.

Both jobs were quite easy to do.

 :y :y
Title: Re: Running 2.5td without viscous fan?
Post by: Pitchfork on 10 January 2010, 13:56:29
Quote
I took the viscous fan off about 3 weeks ago, and replaced the stat at the same time.

It runs perfect now.  Gets up to about 80 quicker and then holds steady at that temp.

Both jobs were quite easy to do.

 :y :y
Interesting because when I removed mine, the steady-state temperature went from 92.5 to 97.5 yet yours is a 80 without the viscous
Title: Re: Running 2.5td without viscous fan?
Post by: charlie on 10 January 2010, 14:51:53
mines is the same temp,when running as bp's.I also took viscous off and replaced the stat.
Title: Re: Running 2.5td without viscous fan?
Post by: TheBoy on 10 January 2010, 18:33:28
Quote
Quote
I took the viscous fan off about 3 weeks ago, and replaced the stat at the same time.

It runs perfect now.  Gets up to about 80 quicker and then holds steady at that temp.

Both jobs were quite easy to do.

 :y :y
Interesting because when I removed mine, the steady-state temperature went from 92.5 to 97.5 yet yours is a 80 without the viscous
gauges vary between facelift and earlier
Title: Re: Running 2.5td without viscous fan?
Post by: chartz on 11 January 2010, 15:35:51
I strongly maintain that you should clean the aircon radiator before doing anything else: it is all important to keep a good airflow through both rads. And since the aircon one is first on the path, it seems pretty obvious to do it first, doesn't it?
My thermostat was changed too, but this had no effect on the behaviour of the viscous clutch.
My temps are 92,5 with fan and 97 without fan. But what is important I was told is the fact that the needle should always be right in the middle of the scale (at noon for BMW owners). The temp shown is probably wrong anyway... I could not keep the fan out in summer, no way, but this was before cleaning the rad. These are the normal temps, and 80 (pre-facelift) always shows a bad thermostat, or a new one probably fitted the wrong way—or defective. Is your heating working properly? On mine, it is fully operational after 5 minutes' drive, which is normal according to BMW people.
Title: Re: Running 2.5td without viscous fan?
Post by: TheBoy on 11 January 2010, 17:20:04
Quote
I strongly maintain that you should clean the aircon radiator before doing anything else: it is all important to keep a good airflow through both rads. And since the aircon one is first on the path, it seems pretty obvious to do it first, doesn't it?
My thermostat was changed too, but this had no effect on the behaviour of the viscous clutch.
My temps are 92,5 with fan and 97 without fan. But what is important I was told is the fact that the needle should always be right in the middle of the scale (at noon for BMW owners). The temp shown is probably wrong anyway... I could not keep the fan out in summer, no way, but this was before cleaning the rad. These are the normal temps, and 80 (pre-facelift) always shows a bad thermostat, or a new one probably fitted the wrong way—or defective. Is your heating working properly? On mine, it is fully operational after 5 minutes' drive, which is normal according to BMW people.
Correct - a good airflow across the rad is essential for that engine, which does seem to suffer cooling issues.  Also a good rad (known to be completely silted up at around 120k).

If the BMW lump has been abused, servicing wise, at any point in its history (remember, initiall 4.5k max (later 7.5k max to please fleet managers) oild change intervals), then a good, strong oil flush may be needed, as the piston cooling jets may clog. Result, overheating - drastically if completely blocked.


Facelift gauge is marked 80/100C, as opposed to 90/100C, so 85C on gauge would be expected cruise temp, rising to 93C. If a facelift got to 95C, or prefacelift to 98C, I would start to be concerned.


Note, if the stat is working properly, and the rad is working properly, the viscous should have zero effect (other than wasted noise/energy), unless working hard at low speed (towing), even then, leccy fans should be able to keep up.
Title: Re: Running 2.5td without viscous fan?
Post by: chartz on 11 January 2010, 19:05:56
Quote
Note, if the stat is working properly, and the rad is working properly, the viscous should have zero effect (other than wasted noise/energy), unless working hard at low speed (towing), even then, leccy fans should be able to keep up.
Indeed, if the aircon radiator isn't obstructed! In hot summertime, they are always on anyway! (okay I live in Burgundy and I go to Midi on holidays)