The Mitsubishi Pajero Owners Club®

[helijohn]

My little Paj runs so cold that I want to fit an electric fan.  It has a fan at the front for the aircon so I fancy decommissioning the aircon and using the fan for engine temp regulation. Has anyone done something like this?

FAN CLICK ME

[Google]

[Roadrunner2110]

There must be a reason it's running cold, possibly no thermostat or stuck open, faulty gauge/sender, blocked heater matrix giving the impression of it running cold. There are many reasons.

As for decommissioning the A/C and using that fan, I certainly wouldn't recomment it IMO as that fan is not designed for cooling anything apart from the heat generated by the A/C.

IMO I would find why it's running cold or appears to be running cold first.

[peteinchad]

I have wired my air con fan so I can switch it on manually - it doesn't noticeably add any extra cooling..

[helijohn]

[The procrastinator]

[helijohn]

[KEVINBUK]

It doesnt sound like you have a problem to me ?  

I suppose for the winter you could go Landrover'ish and fit a radiator "muff" like this...

http://www.rimmerbros.co.uk/Item--i-LL1229BLACKBP?utm_source=google&utm_medium=cpc&utm_campaign=PLA&gclid=Cj0KEQiAoby1BRDA-fPXtITt3f0BEiQAPCkqQRhbIhQtUXY2Vemrfir76At7hs-1ztzFjB0zPBgasKUaAlUy8P8HAQ

But you would end up driving through a hedge as you would not dare take your eyes off the temperature gauge.

K  

[peteinchad]

[helijohn]

[peteinchad]

[helijohn]

[peteinchad]

The standard gauges are not very accurate - but if yours is reading low because of a duff sender then it may be making you think that your engine is running too cold. That is what I thought with mine so I fitted an extra digital temperature gauge to check.

My temperature was normal (except in traffic jams) on the new gauge so I replaced the sender for the stock gauge and it now reads normal.

[assassin]

Avoid electric fans, they fit viscous for a reason and that is they are the best fan for the job.

Viscous have a bi-metal spring which opens a valve in relation to temperature so they are proportional, in simple terms as the engine temperature rises the viscous bi-metal spring opens more to allow the fan to speed up, and it takes the underbonnet temperature into account to control the heat from exhaust manifolds and exhausts as well as the 20% of heat radiated from the engine block and the radiator. Being proportional also means reacts to the temperature progressively to prevent the temperature becoming excessive.

Electric fans work differently, they are simply on/off units and this causes problems, they only work off coolant temperature and give a fixed airflow meaning they are slow to react and can provide excessive cooling leading to thermal shock of major engine components which in simple terms means the engine gets overheated before they kick in, and when they do they can take so much heat out so quickly they can damage components.

Heat soak for beginners, what is heat soak? in simple terms you are travelling down the motorway with Cyril the cruise control on set at 70 MPH, your engine speed is consistent, your engine load is fairly consistent, and your air flow is fairly consistent; then it happens, the dreaded disco brake lights from the vehicles in front leading to a traffic jam. You remove the engine load, you remove the airflow which until now were all proportional and have now become disproportionate, you lose the engine load and the 70 MPH airflow but the heat remains.
Instead of having all that airflow you haven't but you still have the heat which has to be dissipated with no airflow and this is heat soak. What happens is this heat rises under the bonnet and collects.

Understand how airflow works, all underbonnet airflow has a direction and this is for good reason, all major components are sited in this airflow so it has a defined path to take and this is through all the radiators and onto the front of the engine, then down the sides of the engine to cool the turbo, alternator, exhaust manifold, the front (hottest) part of the exhaust, then it goes out under the vehicle to cool the exhaust.

With a viscous coupling it will increase its speed proportionally as soon as the temperature begins to rise and will continue to increase speed to the point where it reaches the required amount of airflow to stabilise the underbonnet temperature and this is called soft airflow as it does it gently. All engines have something called MTHS which stands for maximum thermal heat soak which is the maximum temperature the engine should reach under such circumstances and with a progressive fan operation from the viscous it wont reach this temperature and it will provide and maintain a constant temperature.

With an electric fan using coolant and not conduction and ambient underbonnet temperature you create more problems, first the heat will rise much more and rely solely on the water to cool it instead of a viscous fan which will be cooling and this needs time to travel around the engine to the thermostat, which in turn needs time to open and remember instead of doing about 2000RPM your engine is idling at around 750 RPM which means about one third of the speed which means water pump speed is massively decreased and takes much longer to pump overheating water round to the radiator and its thermo switch to operate the electric fans. When the electric fans kick in they run at massive speeds and give a huge airflow to a much hotter engine which has seriously exceeded its MTHS meaning you are in danger of permanent damage to your engine from overheating anyway, and it actually overcools it, this damages head gaskets, turbochargers, and the internals of the engine from thermal shock as overcooled water runs back to an overheating engine.

[The procrastinator]

The standard Mitsi is engineered to operate in extreme weather conditions, but the 'East Midlands' obviously pushes it outside of its design envelope

[helijohn]

For me the problem is made worse by the fact I mostly use the motor for only a few miles commute.  So every trip the engine is still on choke.  So the question is what can I do to get a quicker warm up or even just get ti warmed up.