Had to get under the car yesterday , as had picked up a bit of rubbish off the road and it was stuck under the chassis , Nothing harmfull just a load of poly sheet . However noticed this Matrix with 2 pipes running to it on the drivers side ,attached to chassis . Any idea what piece of kit it is and why is it in that position .

I notice you have a diesel. That might be the fuel cooler.

It is a fuel cooler.

Well i never , i am learning something new every day , assume from the previous note that only on Diesel cars , Does it run all the time , or is it controlled by a Temp sensor , for hot climate running , assume one would not need it during winter . Just general interest . Thanks as always .

It is allways running (well when the engine is). Due to the very high pressures in the PD fuel system (2050 bar in the injector) the diesel fuel gets very hot. As fuel is returned back to the tank it needs to be cooled down so it doesnt damage the plastic fuel tank.

2050BAR, you sure thats right??

thats very nearly 30,000psi :eek:

not saying your wrong mate but thats a chuffing high pressure system

In the injector yes that is right. Hence the reason the cambelts on the PD engines are nearly 2inches wide.

bloody hell thats a high pressure. no wonder my mate was told under no circumstances to mess with his peugeot hdi fueling system

Well thats done it for me , not touching anything other than oil dipstick , topup coolant and screen wash , the rest i will leave to the Techies , say no more . Gone are the days when i would play around under one of these machines . 32 ibs on the tyres is all the pressure i want to see . Thanks for the Technical low down , . :eek:

2050 Bar!

I always thought common rails ran at a few hundred bar and the PD system along with it.

Never guessed it was that high!

Ever been any nasty accidents involving injectors?

That would be like a hot knife through butter.

Ever been any nasty accidents involving injectors?

No as that is internal pressure in the injector body and you cant get in there. Break off pressure is around 400 bar for 1st stage and 700 bar for 2nd stage IIRC (without checking my notes).

And as the engine is stopped pressure is pretty much nowt as its all mechanically driven.