Roar from Engine - Sometimes - 2001 TD5 Defender

[Cameron_Def]

Another 'What the' on the Defender, sometimes when I take off, the engine has a different roar, as if another fan is working or something, as if the radiator fan has kicked in or something, the sound increases with revs, its not when its hot (sometimes happens when I just finish a HW run, other time when I just turn it on)

It goes away after a while and will not come back til pluto alings again with Mars, and it happens... there is no power lose, or anything unusual, engine temp is always the same.. usual things are normal (oil, coolent etc etc) so I am guessing its another cooling fan ???

Oh and it happens Aircon on or off ..

hmmm any suggestions, I am not worried or anything, just wanting to know what it could be!

Thanks,

Cameron

[muddymech]

just an idea, think its probably the viscous fan trying to keep up with the engine.

[Cameron_Def]

just an idea, think its probably the viscous fan trying to keep up with the engine.

The what doing what keeping up with the engine ?

Whats a viscous fan, and why is it hiding in my engine bay ?


(ps I am not all that car friendly terms wise)

[Reads90]

The what doing what keeping up with the engine ?

Whats a viscous fan, and why is it hiding in my engine bay ?


(ps I am not all that car friendly terms wise)

:D :D
It is the big fan that sits between you rad and the engine. will spin freely untill sort of needed. Reason they are not fixed and designed to spin freely is to save fuel. and keep the temp of the car regulated Ie so it does not take ages for it to warm up on cold days

[ladas]

The what doing what keeping up with the engine ?

Whats a viscous fan, and why is it hiding in my engine bay ?


(ps I am not all that car friendly terms wise)

HeHe - love that;)

The viscous fan - is a temperature driven coupling between the engine and the cooling fan - when the engine is cold the fan - should - basically freewheel, when it gets hotter the fluid inside the coupling acts like a clutch (thermo clutch) and engages the fan and makes it spin - the hotter it gets the faster the fan spins and so on.

If the viscous coupling is faulty it can engage the fan all the time - engine can run cooler (sometimes too cool) and fuel consumption suffers a very little.

Easy test - on a cold day (okay bit hard at the moment) maybe in the middle of the night, get a drinking straw or a small peice of plasctic tube, nothing too strong or you could damage the fan.

Whilst you hold the straw or tube in the fan, watch your fingers, get somebody to start the car, when the engine is cold the straw or tube should stop the fan from moving - if it doesn't then there is a posibility that the viscous fan coupling is buggered (technical term)

[ladas]

Sorry easier/safer method

When it is cold, engine everything - with the engine off, see if you can spin the rad fan with your fingers. If it spins - should be okay.

Then warm up the engine to normal temp, switch off and re-do the spin test - if it doesn't spin it should be okay.

[LandyAndy]

Hi Cameron
Have the engine running,bonnet open,aircon off.
See if the electric booster fan is running,if it is Im guessing you have oil in the harness,my Disco was doing this.
Mixed up signals telling the ECU the engine is ocerheating!!!
Andrew

[Captain_Rightfoot]

Mine does the same.

Sometimes when I first start and drive down the street it runs. The engine is cold, so I thought it was some kind of testing function :o I presumed it had some kind of electrical switching mechanism, but I didn't worry about it. :o