Running without the fan shroud or even the whole fan?

Post by **mrbonk** » Mon Jun 06, 2005 11:16 am

Greetings,
I've done my water pump replacement on the weekend (on my TD42 GQ Patrol), but my new fan (to replace the badly cracked one) won't be here for a few days. Is there any reason why I shouldn't drive the car without the radiator fan shroud on? I don't want to put it back on, only to have to remove it again when the fan turns up in a couple of days.

I'm making the assumption that the shroud is there to increase the efficiency of the fan, but it's nice and cool weather at the moment, so that shouldn't be a problem yeah?

As an alternative, can I get away with leaving the fan off altogether, just in case it throws a blade between now and when I can replace it? This thing has a 12V fan in front of the radiator which runs the whole time the A/C is on.....given that the air temp is only getting to low 20's at the moment, will this suffice? I really don't fancy tooling along at highway revs if this thing chucks a blade!!

Post by **sox121** » Mon Jun 06, 2005 12:12 pm

Hi, If most of your driving is done at Hwy speeds then I would leave the fan off, it is only needed when you are stopped at the lights. Use some spaces on the water pump pulley when you put the nuts back on if you need to.

Post by **chimpboy** » Mon Jun 06, 2005 12:19 pm

The shroud makes a big difference to the efficiency of the cooling system because it forces the fan to pull air through the radiator. With no shroud, the fan just pulls air from above and below instead. Fans are just naturally lazy.

I don't know how bad the crack in your fan is so I can't say how likely it is to send a blade flying but I probably wouldn't drive around without the engine fan. It depends on what kind of driving you do though - on any car, the fan does basically nothing above about 40kmh because at that point the air is flowing faster than the fan could pull it anyway.

Only you can decide which risk to take.

Jason

Post by **Tiny** » Mon Jun 06, 2005 12:19 pm

If the shroud isnt there it also becomes very easy to bend over the engine bay when ya trying to fix anything and get cliped by the fan

Post by **mrbonk** » Mon Jun 06, 2005 12:34 pm

Ok. That's what I was hoping. My drive to work in the morning (at around 10 degrees temp presently) = 1 min from my house to highway, then 100kph all the way to town, then ~5mins from highway to work. I figure at those temps, it's not going to cause any grief for the couple of days I may have to do it.

Unfortunately, the cracks in the fan hub are almost as wide as the hub itself, so I think the risk of it chucking a blade is pretty high. Especially now that I've flexed some of the blades while removing the fan to do the water pump. I'd rather not run the risk!

At the moment, with the fan on, around town it gets to less than 1/4 on the temp gauge. The only time it's been anywhere near even half way was while we were driving up the hills to the Bunya Mountains (foot flat to the floor in second gear with a few hundred kg's of gear in the back).

I'll whip the fan off this arvo and hope the new one turns up soon!

Post by **ozy1** » Mon Jun 06, 2005 5:03 pm

just leave the fan on, if it hasnt thrown a blade yet, the chances are it not going to throw a blade for soe time to come,

Post by **Camshaft1** » Mon Jun 06, 2005 5:43 pm

Plastic fan when they break usually just go up anyway. and a plastic fan blade isn't gona go through a bonnet. pretty important things those fans. i wouldn't be takeing it off.

Post by **MKPatrolGuy** » Tue Jun 07, 2005 7:42 am

Camshaft1 wrote:Plastic fan when they break usually just go up anyway. and a plastic fan blade isn't gona go through a bonnet. pretty important things those fans. i wouldn't be takeing it off.

I have seen a bonnet with one of those fan blades through it. So it can happen. The fan is important, do you definitely have to drive it before the fan turns up?

Post by **mrbonk** » Tue Jun 07, 2005 8:51 am

MKPatrolGuy wrote:I have seen a bonnet with one of those fan blades through it. So it can happen. The fan is important, do you definitely have to drive it before the fan turns up?

I'll be trying not to. On the occasions when I've had to, I've tried to keep the revs down as much as possible to reduce the stress on it.

The weather's sort of ok at the moment, so unless it really pisses down with rain, I'll be riding the bike to work. Hopefully it won't take that long for the new one to arrive!

Post by **Red_MAv** » Tue Jun 07, 2005 12:58 pm

Only seen one fan break and that was during a deep river crossing, probably the fan was spinning like crazy then when it hit the water, too much strain and blades sheared off at cracks. Mine had bad cracks for a while before I replaced it with a new one.

Post by **rOd** » Tue Jun 07, 2005 1:11 pm

I would be more concerned of a broken blade ripping the raidiator and vital hoses / piping.

Post by **bogged** » Tue Jun 07, 2005 4:58 pm

the shroud takes what 3-6 mins to remove depending if you have the lower section on there... why wouldnt you just wait instead of risking anything?

Post by **Rainbow Warrior** » Tue Jun 07, 2005 9:50 pm

A TB42 Patrol should run no shroud no problems, mine ran for years with just the side sections, both the bottom and top missing in QLD summers, offroad & on.
A shattered fan can damage a radiator, a cracked one in my Rangie exploded while drag racing a turbo Landcruiser one day at 6500rpm, the thermoclutch was siezed which didn't help, took out 2 cores in the radiator, but I still beat him

But you could have a problem running without a fan, maybe use the A/C fan, but disconnect the wire to the A/C compressor or wire the fan to the ignition coil circuit.

Post by **bogged** » Tue Jun 07, 2005 10:23 pm

Red_MAv wrote:Only seen one fan break and that was during a deep river crossing, probably the fan was spinning like crazy then when it hit the water, too much strain and blades sheared off at cracks. Mine had bad cracks for a while before I replaced it with a new one.

if its a GQ and the fan was still spinnin the clutch fan was fucked. it shouldnt be runnin unless 3/4+ hot...

Post by **turps** » Wed Jun 08, 2005 1:19 am

I still have the fan fitted on my TD42. BUt the shroud hasnt been there for well over 18mths now. Did a desert trip in Nov with very hot days and it ran warm but not hot (guage went to half).
Only reason it aint fitted though is that the engine mounts are stuffed and the fan hits the bottom of the shroud.

Post by **DieselBoy** » Wed Jun 08, 2005 4:31 am

Your problems are lickly to be in the area when you come out of the 100k zone into town for the 5min drive.
You will have a heat surge as the engine rev's drop and the water circulation slows.
The engine will be a opperating temp by then and with out the fan to help control the engine temp.......................................

Post by **Steve_GQ** » Wed Jun 08, 2005 12:08 pm

I havn't had a shroud on for 2 years now. My fan threw a blade through the top of the shroud on a real rough track. I 've had no heating problems at all, only time it goes near half temp

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Running without the fan shroud or even the whole fan?

Running without the fan shroud or even the whole fan?

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