Thread: Engine Saver

Hi Disco Owner.
Get it nice and hot pull over and squeeze the top hose whilst the engine is running(beware hot hose and fan/belts etc) Is the hose under a lot of pressure??? After your earlier post of it spewing its coolant out I wonder if you actually have an early head gasket problem???
Hopefully not.
Andrew

Hi Mox
Im sure your system is perfect for the paddock where you can safely stop from the low speeds encountered there on farm equipment.
Would say definetely not safe for heavier earthmoving equipment wether on or off-road.
POSITIVELY DANGEROUS on the open road,for the user and anyody else in your vicinity.How about a fully loaded road train heading down a nice big hill into a country town.The thing overheats whilst still in the open road speed zone and shuts that nice expensive motor down.Now try and slow/stop/steer the behemoth without killing anybody or yourself.I would also thing such a cutt off system would be illegal on the road.
Andrew

Originally Posted by LandyAndy

Hi Disco Owner.
Get it nice and hot pull over and squeeze the top hose whilst the engine is running(beware hot hose and fan/belts etc) Is the hose under a lot of pressure??? After your earlier post of it spewing its coolant out I wonder if you actually have an early head gasket problem???
Hopefully not.
Andrew

Hi LandyAndy,All sorted mate;

Coolant Level was rather low inside cooling system , the in-line sensor wasn't quite picking up coolant presence inside top hose when engine was cold , once it was hot it was okay , no buzzing , this morning with expansion tank topped right up to level I took it for another test drive for 10-15 min of hard driving & it stopped buzzing and it has been off since , phew even when on the driveway with vehicle facing down or facing up or sideway the in-line sensor is still picking up coolant presence inside Rad top-hose when Cold.

Further regarding the concerns expressed by Landy Andy regarding the overheat protection system with power fed to the fuel solenoid via a temperature sensitive switch on the head:

No need for buzzer and/or warning light which can malfunction or driver not notice /ignore them and the buzzer at least costs money. For Land Rovers seems to me a push button as easily accessable as a headlight dip switch is adequate if every driver of the vehicle is well aware of its function. Having to use it would normally be no different to handling minor emergencies that drivers have to deal with all the time.

In applications where the fuel solenoid suddenly switched off without warning may cause a major problem from loss of power assistance for braking and steering, eg in a truck, inertia keeping the motor turning would generally give plenty of time to activate the override.

Note when fuel solenoids - effectively electrically operated taps are used in applications where the injector pump has a mechanical shutoff, the motor does not stop instantly. It first sounds as if it is starving for fuel, then stops slowly but immediately recovers when the override is hit before it does. I am sure some plumbing could be devised so motors initially lose power to give warning before stopping completely if deemed desirable.

I initially had a 95 degree switch on my 300 Tdi. Found it a bit of a nuisance. Went off too readily under heavy load in hot weather. There is one motor at least - I think Kubota that normally runs hot that the bloke at Shepp Speedo recommends 115 degree switches for.

After changing the timing belt 12 months ago I have not replaced the fan, shroud or air conditioner condensor - the latter needing removing for another reason. Also have done a few other things to allow better air flow. Seems with the standard setup the big fan is necessary largely to push air past all the obstructions (a sentiment I have seen expressed on this forum). the 105 degree switch has since stopped the motor once, when it had been idling for nearly half an hour on a hot day -and the radiator cap did not blow. Possible disbelievers should note that diesel engines are more efficient than petrol ones and for the same power output produce less heat from the radiator and exhaust.

Hi Mox
If your fan is trying to PUSH air past all its obstructions I suggest you turn it around.An engine fan PULLS air thru the radiators and out over the engine,the fan shroud is an important part of this as the fan WILL optain its air supply from the extremities of its blades not thru the ducting the fan shroud provides.
Andrew

More comments on fans, especially for Landy Andy:
Regarding turning fans around, it it does not make the air go in the other direction any more than turning your right hand around makes it like your left hand. With fan blades that are normally curved when looking from the ends towards the hub, turning them round and running them in the same direction simply makes them churn the air more rather than scoop it through, draw less through the radiator and probably make them heavier to drive. I have seen engines on farm machines that have had overheating problems due to the fan being installed the wrong way round. Also have noticed the fan on backwards on the odd road vehicle, which would also make overheating more likely.

On some late model vehicles with serpentine belts where the fan runs the opposite way to the crankshaft, the fan blades are also the other way around. I installed a steel one of these from a post 1987 6 cylinder Jeep backwards on a tractor with a front end loader so it efficiently blows air forward. Stopped the problem of chaff from hay on forks blocking the radiator. Had seen the same arrangement on dozers to reduce clogging from heavy dust stirred up just in front of them.

I agree that a fan shroud is important with a fan behind the radiator. However, from noticing the way dust and chaff regularly blocks some parts of the radiator more than others in headers, (ie combine harvesters) the fan draws more air through some areas than others due to differing peripheral speeds of the blades along their length and turbulence.

To me, it appears the the 300 Tdi Defender fan location with the shroud offset relative to it is a poor design which probably results in the fan drawing far more air through parts of the radiator than the intercooler, which needs high air flow first. It appears two electric fans in front of the radiator instead would be more efficient in this respect. On road vehicles, there is enough air going through the radiator most of the time so they don't need to be switched on. However, because of the bit of extra obstruction they create, in some marginal situations they would need to be switched on just because of it. The electric fan that was bolted to the front of the air conditioner condensor on my Defender was a bit self defeating in this respect as well as making the condensor and radiator harder to clean. In many conditions you can get away without a fan, including with minimal risk of engine damage from overheating if a protection device is operational.

This is less likely if the cooling system is partially blocked or has inadequate capacity. Of interest is that in the 1950's my uncle had a Riley sports car. It had one belt driving the generator and water pump and the other the fan. He drove it for 8 years largely around Melbourne without a fan belt. The only times overheating was a worry was occasionally with long waits at traffic lights. Reckons on very hot days he often drove past cars on the side of the road with bonnets up , including many FJ Holdens, supposedly built for Australian conditions.

Mi Mox
The cooling fan on my grader is computer controlled.ALL the cooling heat exchangers(radiator,intercooler,oil coolers) are locared in a rear pod behind the engine,the cooling fan is hydraulic operated,it is operated at a timed interval to run back to front to blow all the rubbish out of the heat exchangers,VERY EFFECTIVE.
There is a major problem with this system.At the moment the manufacturers have over-ridden the operator time out for reversing to a short blast I cant give via the computer dash.
When transporting the grader during summer on 40C plus days the reversal of the fans overheats the cooling system.All the bells whistles light up and within a minute the computer limits H.P and the thing almost dies.Dont worry,the first 3 times it happened I stopped and checked out for leaks,now I just pull over and wait for the fan to go the right way round.
They admit the cooling system reversal is a BIG problem whilst transporting and are looking at an ECU blockout when in transport mode.
Driven big Headers that auto clean cooling fans too when I was once working as a sod busters hired help!!!.Saves getting itch cleaning with an air gun!!!
Andrew