electric fan 300tdi

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The Mad Hat Man said:
I think yu misunderstand how these fans work?

A viscous fan is attached to the engine, so....
A) it only works when the engine is running.
B) the airflow is directly proportional to the engine speed, not to the cooling required.

An electric fan is ( or can be) driven independently of the engine and therefore......
A) can be turned on or off by the cooling requirements, irrespective of engine speed.
B) the airflow is controlled purely by the fan controls, so that it enables quicker warm-up periods, longer cooling (after the engine is turned off), and the option to turn it off completely if wading.

In short, an electric fan can do everything a viscous fan can do, and more. It has to be the better option.
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Millions of large semi's in the USA use this set up and works quit well and it increases MPG. What is nice is if the driver shuts the motor off before properly cooled the fan stays on then when properly cooled turns off. all with sensors and relays. On a 4000 mile trip cross country they may only need the fan to run in the southwest/desert area of the USA and the rest of the time the fan never turns on as enough air flow keeps engine cool, And for 5 months in the mid west the fan may never come on. a great saving in fuel. and there motors go for 750k miles or more , they have million miles clubs for semi's with original motor and still workin everyday.


So listen to MHM he knows what he talking about
 
Trust me a viscous fan is not proportional to engine speed it's very design means it works of the air temperature of the air coming through the rad try a google and understand the properties of the oil in the fan.
When they lock in there is till a limited amount of slip, if they lock up solid they overcool and roar pretty loud!
Ive worded that wrong, engine speed is a factor but the main control is the temp of the air over the bimetal switch in the fan hub, then obviously the faster the engine is turning the faster the fan will turn.


Lynall
 
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john winsemius said:
Millions of large semi's in the USA use this set up and works quit well and it increases MPG. What is nice is if the driver shuts the motor off before properly cooled the fan stays on then when properly cooled turns off. all with sensors and relays. On a 4000 mile trip cross country they may only need the fan to run in the southwest/desert area of the USA and the rest of the time the fan never turns on as enough air flow keeps engine cool, And for 5 months in the mid west the fan may never come on. a great saving in fuel. and there motors go for 750k miles or more , they have million miles clubs for semi's with original motor and still workin everyday.


So listen to MHM he knows what he talking about
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Are you sure large trucks in the usa run electric fans?
I have been repairing trucks for 20 years now and have never seen one fitted with an electric cooling fan.



Lynall
 
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I binned the Viscous fan soon after I got the disco and replaced it with an electric on although it came with a temperature solonoid I decided to run it manually via a switch. I also added an aftermarket temp gauge and flick the fan on when it goes above 80 degrees. I do recomend one of these as the landys temp guage barely gets to the middle of the dial and doent move i can have up to a 20 degree swing without it showing on the standard one
 
A 300tdi (in fact most of the LR diesels) will go almost all of the time without a fan at all. I had an electric fan on 2.5NA for about 4 years and I think it came on once! I have one on a 300tdi and its not been used in anger yet, that includes sitting in traffic jams on hot days.

When you’re driving along there is positive air movement cooling the radiator, the only time a fan is really needed is when you’re sitting stationary, at this point the engine is now not loaded and will not be producing as much heat anyway.

This talk of thermal shock is nonsense and really does not apply here; the stat will regulate the coolant temperature, to start off with and under light loads it will open and close sending slugs of cooler water into the system, so the engine is getting hit with water of a profoundly different temperature no matter how it is cooled. If you take your LR for a thrash down the motorway from cold you’re going to risk shocking it more than through electric cooling.

The through the fin fixings are not a good idea to be honest, especially if the radaitor is not in it's prime.
 
ive had several cars and a talbot express van with leccy fans..... none of them have come on in normal driving conditions..... they seem to be designed to only come on when the temp gauge is well in the red.... which i think is far too late. i often wire a switch accross the temp sensor so i can turn the fan on before things get too hot. ive towed caravans with small hatchbacks....astra , megane etc.... flickin the fan on before a hill will usually reduce the coolant temp rather than have it rising as you drag up the hill. ive even had cars where the leccy fans have seized cos theyve never actually come on
 
If you take a stock temp gauge, and an aftermarket gauge with a 5-10 degrees at a time readout type dial and you run them side by side, the aftermarket gauge will be up about 10-15 degrees before the stock gauge even starts to shift. They do this because the engine is still well within limits, even when its going towards or in the red the engine is still within limits, these gauges are designed to scare the average person into stopping, and also because the chances are there is a problem.

I have an aftermarket gauge, when crusing on the motorway at 65ish it sits about 89°C, if I drive a bit faster it will go up a degree or two and sit there till I slow down, if I go up a long hill it will go up a degree or two, if I go down a hill on light throttle at motorway speeds the temp will even fall a couple of degrees. On a stock gauge it wouldn't even budge as it would frighten people.

The cooling system is pressured and ought to have a proper dose of anti-freeze in it, therefore the water will not boil until its considerably hotter than 100°C (it depends on how much anti-freeze and the system operating temperature). For example, the 300TDI’s coolant water WITHOUT anti-freeze will not boil until about 120°C.

So, if a diesel engine is running with coolant temp up about 100°C for example, there really is no worry, obviously if you’re going along at 50mph on a cool day with light throttle then something isn’t right as it should be able to regulate it’s temperature to about 88°C.

So if the electric fans don’t come on till the gauge is nearly in the red I would not say that is any cause for concern.
 
richard prince said:
ok well nice debate over the issue sorry for causing this to all,the reason im looking at an electric fan is due to the fact when i tug my caravan up long inclines the 300 goes right up to the start of the red,if in 3rd or 4th gear the engine revs higher but the 300 is moving at a lot slower pace so i end uphaving to put the heaters on in the car to help speed the cooling time as i dont like the engine that hot its not good for my engine,checked and replaced water pump,thermostat,50/50 coolant n water,new rad 12 month ago,de egr and de cat standard fuel setting on pump,head gasket checked all ok,full service every 6 month,all filters and oils,and yip my brakes are sweet lol.other than this temp never moves above half on gauge round town or motorway,and believe me it gets some hammer at times,if theres any thing ive missed then please let me know i just thought this was the best idea for the hill issue with the caravan,
cheers
richard
p.s.reading all this has made my night lol but its also yet another fine learning curve.
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I think it is an irrelevance as to whether you use electric or viscous fans. Get rid of the root cause and all will be well! No traffic jams, no angry motorists, driving faster and easier - of course, lose the van!!
 
Hi All, I know this is an old thread, but is still read by lots of people wondering the same thing.

I Live in southern Spain and bought a Kenlowe - it's not up to the job if you have a high ambient heat, belting up a long hill. Viscous replaced and better cooling.

I reckon with Temperatures in the UK you would be ok though, and with diesel at 97p a litre in Gibraltar I'll suffer the higher minimal fuel efficiency.

Good thread though and I think it's personal choice - if you have Morocco planned then viscous all the way!
 
landymangib said:
Hi All, I know this is an old thread, but is still read by lots of people wondering the same thing.

I Live in southern Spain and bought a Kenlowe - it's not up to the job if you have a high ambient heat, belting up a long hill. Viscous replaced and better cooling.

I reckon with Temperatures in the UK you would be ok though, and with diesel at 97p a litre in Gibraltar I'll suffer the higher minimal fuel efficiency.

Good thread though and I think it's personal choice - if you have Morocco planned then viscous all the way!
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F@@k southern Spain The death valley and desert SW American is a hell'of a lot hotter and they works just fine
 
Viscous fans use energy. My 300tdi without viscous does 30 mpg. Try getting that without driving like a fossil with viscous. The electric fan never runs all winter. That at least 6 months of fuel saving with our climate
 
i know its an old post of mine,i need a new viscous fan coupling is it worth me getting one or go for electric theres so many yes/no answers it only goes very close to the red when tugging van up long hills.
 
I don't understand ?

My 1995 300 tdi has a viscous fan and two elelctric fans in front of the radiator as standard from the factory.

Surely all have this ?

I went to add an electric fan to assist my intercooler and discovered the two fans. I have never heard them operate mind you, even here in Australia.
 
Jason F said:
I don't understand ?

My 1995 300 tdi has a viscous fan and two elelctric fans in front of the radiator as standard from the factory.

Surely all have this ?

I went to add an electric fan to assist my intercooler and discovered the two fans. I have never heard them operate mind you, even here in Australia.
Click to expand...
air con at a guess.
 
My standard 1995 300 tdi comes with two electric fans in front of the radiator and the viscous fan behind. So I presume you can order the standard fans. I have never heard the electric fans start up.

Maybe I should wire them in to a digital WGT meter at the alarm set point to turn them on?
 
The two fans in front of the rad are, as MHM says, air conditioning fans .. they don't start up till you turn the aircon on.
 
Bummer.

I thought that they were operated from a thermostat when the water temp got too high.

I suppose it would not hurt to have them come on during high EGT though.

Thanks for that info.
 
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