Isuzu Trooper Owners Club UK™

[GJones]

Hi, My engine fan has started to make a vibrating noise at idle (sometimes), took the fan off and the noise stopped, the noise is very like something touching the engine but checked for this and it's not that, anyone have any ideas? Regards Gordon.

[Google]

[Browndoff]

The fan-shroud is a fairly flexible chunk of plastic - if it's NOT mounted properly, it can distort and touch the whirling fan-blades.

The fan is driven, through the Viscous-Fluid-Clutch, by the fan-belt - if there were any fibre sticking out of a slightly-frayed BELT - THAT could touch something and make a similar noise.
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2002 LWB Trooper 3.0L
I've done some major repairs, including replacing half-shaft, replacing fuel-injectors etc.

[crusader]

Electric is the way.  
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On victory, you deserve beer, on defeat, you need it.

[Browndoff]

I disagree most strongly! Even if a Viscous-Fluid-Clutch were faulty - and you had to replace the fluid - that's a piece of cake  - compared to replacing the whole unit with something from another type of vehicle!

I THOUGHT I had to replace the fluid in mine ['cos I had a REAL overheating problem], so I bought some 'thicker' fluid On-Line and replaced the original stuff. It was easy and uncomplicated - and the result was certainly a new fan with much better TORQUE!

This guy's problem is entirely different, though! He's got a simple 'mechanical' problem of something touching the Fan-Blades. That has to be either because the Fan is turning OUTSIDE the 'intended' area [which could be because the shaft is bent, bearings are gone etc.] - or something is INTRUDING INTO the proper turning-circle of the Fan [like a twisted Fan-Cowling, or whatever].
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2002 LWB Trooper 3.0L
I've done some major repairs, including replacing half-shaft, replacing fuel-injectors etc.

[crusader]

Was just a suggestion.   I fitted a twin speed kenlow to mine. Never had any issues and realised how little the fan is actually needed. Surely the less load on the engine and water pump has to be worth it.
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On victory, you deserve beer, on defeat, you need it.

[Browndoff]

Sorry if I seemed 'over-excited' by your suggestion. The truth is that ALL items which use energy - from wheels to fans to lights, heaters etc. get that energy from the ENGINE - even if it is through the generator and the battery, it still comes from the engine originally. All along the line, each stage is less than 100% efficient - so each stage wastes some of the energy - so, in fact, something which uses ELECTRICAL power, wastes more than the same power-level from something driven directly from the engine itself [like the fan driven by the belt].

None of the energy used in the vehicle is 'free' - it all comes, eventually, from the energy stored in the fuel-tank.

My real objection to the after-market electrical fans is all the extra work to remove the original system and fit something entirely new. That may well be worth-while for something which increases power or traction  at the wheels - but any system which removes enough heat - is a 'good' coolant-system!
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2002 LWB Trooper 3.0L
I've done some major repairs, including replacing half-shaft, replacing fuel-injectors etc.

[darren m]

how do you check or replace the viscose fan clutch fluid -- never even knew it existed

pics if poss
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93 SWB 3.1Turbo Duty intercooler

99 LWB 3.0 TD Citation

2000 LWB 3.0 / 3.1TD Duty conversion

[Browndoff]

Don't worry about it! It'll probably NEVER go wrong! Even mine, though slightly less than 100% WAS NOT to blame for my over-heating problem - it was really down to a clogged RADIATOR - which I had to replace in the end.

For those who might have a REAL problem with it - the strip down is easy and replacing the fluid is cheap. The simplest test of its efficiency is the Twisted-Roll of Cardboard test. Just twist together a roll from a cereal-box and stick it into the turning fan when the engine is COLD - the fan should STOP - 'cos the Viscous-Fluid-Clutch is not up to 'heat' and so it lets the Fan free-wheel with very LOW torque.

When the engine is HOT, the radiator heats the little spring on front of the  Viscous-Fluid-Clutch and it closes its internal valves and joins the Fan to the Water-Pump-Shaft with a HIGH torque. That means if you stick the twist of cardboard into the whirling Fan when the engine is HOT - it should SHRED the cardboard!! If it stops even when HOT - then your  Viscous-Fluid-Clutch is not up to the job and it's NOT driving cold air through the Radiator.

Don't worry about this test - it's NOT as dangerous as it might seem! The nylon Fan-Blades are well able to tear through a twist of cardboard with no damage to them selves - and  your fingers should be entirely safe if the piece of cardboard is long-enough!
[img][/img]
The pictures show the tools required and the type of fluid to use as a replacement - I got it from a website catering for RC-model-cars! Toyota also sell it for the fan-clutch in the Hilux.
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2002 LWB Trooper 3.0L
I've done some major repairs, including replacing half-shaft, replacing fuel-injectors etc.