td5 fuel filter gets hot

[treebloke]

Changed the fuel filter today and within minutes it was hot, not to hot that you cannot touch it but certainly very warm.

I guess this is due to the fuel returning back to the tank after running through the system?.

[Tanuki]

Don't fret about it.

The fuel-circulation on a TD5 is - to the uninitiated - both deeply strange and potentially a cause for unnecessary anxiety.

You've got a low- and high-pressure feed from the fuel-pump to the filter (where any bubbles or air are separated from the fuel) then after the high-pressure fuel's been fed up to the engine and put through an even-higher-pressure engine-driven fuel-pump to supply the injectors, any excess (which can be at seriously-high temperatures because it's been fed at mega-high pressures through channels in the cylinder-head only millimetres away from the combustion-process going on in the cylinders) is fed back through an engine-coolant-cooled heat-exchanger (where it may lose a bit of heat if it's lucky) to the fuel-pump for another cycle round the process.

Seeing steam rising from the fuel-filter in wet weather is quite normal on a TD5.

--Tanuki

"The sudden moistness can come as a shock for the uninitiated".

[chrisbowler]

Just to add, the injectors are a high pressure generator, there is no high pressure pump in a TD5 engine. The injectors have a chamber that when the cam moves a rocker arm, pushes a plunger that compresses the fuel, then at the right time an electric switch fired by ecu, opens the injector into the cylinder.

Chris bowler

[clive-240]

On the fuel cooler point mine has no water connected too it as it leaks is this going to cause me a problem

[RedLineMike]

I ru my td5 with the fuel cooler bypassed, now given how hot diesel is when they make it I haven't found any cause to worry, plus having a big fuel tank allows it to cool of to a degree before it goes back I to the system

[treebloke]

Thanks for the replies lads, much appreciated.