viscus fan

[Russell]

hi all.
I seam to be having a overheating issue. When i am in really slow moving traffic the jeep seams to be getting hot but when i am moving at 35 or moor its fine and cools right down.  How do you check if the fan is OK?
Last night it overheated to about 110 degrees but but this morning i checked the water and theres loads in there also i cant see water in oil or oil in water.
I recently replaced the water pump but did not refit the fan cowl could that be it?

[The Smiths]

Fan cowl needs to be on, then see if you still have the problem

[dxmedia]

Fan cowl needs to be on, then see if you still have the problem

Is the 2.5 that crap  :shock: :shock:

Wouldn't fitting a 3 or 4 core rad be a better solution?


If it's a 4.0 I'd not be too concened about the lack of cowel, is the viscous unit actually working?

[Russell]

Its  the 4 litre how do you tell if the fan is working?
when you hold the engine at about 3k rpm you can hear the fan spin for a couple of seconds then it fades away.
Hopfully i still have the cowl if so i will refit it.

[daggie]

thermostat

[Delk]

After you start the engine you should hear the fan quite down when the viscous fan starts to slip. The fan will continue to move but not as fast as the engine. When the engine warms up enough to require the fan the viscoucs coupling will start to grab and the fan will start making more noise again.

[dxmedia]

With a cold engine spin the fan - you should feel little to no resitance

With the engine hot (in your case creeping to too hot). Kill the engine, pop the bonnet and spin the fan. It should be hard to spin. If there's still little to no resistance then the viscous coupling is knackered.

Pop the stat out, stick it in a pan of water with a sugar thermometer and see what temperature the stat opens at too.

[J66P]

the fan will from stone cold have some resistance, run it for just a couple of minutes then turn it off and try the spin test

[Russell]

i had a quick look today and when cold it has a bit of resistance but when it heats up to 100 on the temperature gauge and thats just on tickover the fan has very little resistance. As soon as you drive and it has a bit of air flow through the rad the temperature comes straight down and stays really low. Ill have a look at the stat tomorrow and refit the cowl if i can find it.

[dxmedia]

i had a quick look today and when cold it has a bit of resistance but when it heats up to 100 on the temperature gauge and thats just on tickover the fan has very little resistance.

Viscous unit is foobared.



The reason that when you drive it cools down is because of the air flow through the rad.

[Russell]

I fitted a new thermostat and flushed the cooland system today which seams to have made it a bit better but it still sits at around 100 when in traffic so i have now ordered a new fan clutch. I hope this does it because i cant find the fan cowl.

[dxmedia]

Missing fan cowel will make f'all difference really.

If your viscous unit doesn't lock up when you get to temp. then you've never got fan cooling, just the air flow through the rad from driving.