75ZT Community

Is the diesel cooler really necessary?

Would have thought if it was not it would have either gone completely via Project Drive or just from those countries deemed to be 'cold'.

AFAIK the fuel gets warm and when it returns to the tank goes through the cooler for safety reasons ie make sure no chance of it combusting

Also if it was to condense in the tank the water would mix with the fuel and could cause issues

I had read somewhere that someone had bypassed the cooler due to it leaking.

The diesel comes back out of the high pressure pump quite hot. It loses some of this heat through the cooler. The rest of the heat goes into the fuel tank and stops the fuel from gelling in really cold weather.

Reviving this old tread with a question.

Will the cooler only leak when the diesel is under pressure from the pump?

Once this pressure has been relieved (by diesel loss from the leak) will the leak cease?

Thanks

Mike

Hard one to answer. My guess would be it only leaks under pressure, as I believe there's only ever flow through it while pressure is in the system from the fuel return. But I'm not a fuel systems expert.

Is there a thermostatic control, where the fuel doesn't flow through the cooler or is that another vehicle I'm thinking of.

Regards the markets where it's necessary: that's a difficult argument to make. Cars sold into one market will very likely spend at least a little time in other climates, if the owner holidays. So for example a car built for the UK market might not really need it if it stays in the UK, go on holiday to Spain for example, and it's a whole new rounders game.

Mike look up Rob (trebor) threads he had trouble with his oil cooler, or are you referring to the fuel cooler at the rear of the diesel rover.
Oil cooler.
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Fuel cooler im sure you are talking about this.
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Pretty sure he's referring to the one down the back underneath. And your photo confirms what I'd thought, there's a cooler bypass valve. In your photo I think I see a bodgelock (AKA Scotchlock) and they are a bad thing.

Yes it is indeed the one to the rear of the offside rear wheel.

I replaced the valve in the middle of the cooler and very little diesel leaked out from the open fuel hoses. As the car has not run for a while I think that the usual situation is that the fuel in the pipework of the cooler is under pressure.

I have a replacement earth wire to fit to the cooler but I am not sure where the connector is fitted?
It is the opposite end to where the wire is attached to the cooler to the bottom right when you view it.