Dispatch radiator and tank under floor of van

[Peter Palmer]

Just out of curiosity really, a couple of welds have broken on our exhaust brackets so I was bodging it back up this morning to stop it rattling about and noticed a couple of things I hadn't seen before. One is a small radiator or cooler under the passenger seat area below the floor, probably only 6 or 8 inches long with a air scoop on it, what would this be cooling, the diesel for some reason?

The other thing is a smaller plastic tank just in front of the bigger diesel tank with a couple of pipes and wires going to it, it also had some sort of valve that swivels 90 degree. I'm guessing it might be an add blue tank or something but the van has done 200,000 miles now and its never given any sort of additive warning.

Vehicle is a 2015 dispatch 1.6 HDI enterprise 8 valve engine.

[GiveMeABreak]

That will be the DPF Additive tank if it is directly next to the fuel tank. You don't have an SCR (Selective Catalytic Reduction) system on this vehicle, so no Adblue.

As for the other thing, that may be the fuel cooler.

[Peter Palmer]

Ah DPF additive, that's what I was thinking of, should it not need topping up by now though? As for the mini radiator, it does look like its fuel lines running through it but why would the diesel need cooling? its stored in a tank outside the vehicle anyway.

[GiveMeABreak]

Basically it's to cool the hot fuel from the injection pump when being returned back via the return pipes to the fuel tank. It can help prevent evaporation and over heating, especially during the very hot weather we have been having and in hooter climate countries.

[Peter Palmer]

Ok thanks, so its forthe returned fuel and not from the tank, that makes sense.

[GiveMeABreak]

Yes, to cool the fuel before the excess unused fuel is returned to the tank.

[RichardW]

Whilst it's cooling the fuel its function is to cool the HP injection pump - the high pressures involved produce a lot of heat so an excess of fuel is circulated through the pump and the cooler under the car takes the heat out.

Unlikely it has made it to 200k without the additive being refilled, it usually needs doing at around 80 - 100k

[Peter Palmer]

Whilst it's cooling the fuel its function is to cool the HP injection pump - the high pressures involved produce a lot of heat so an excess of fuel is circulated through the pump and the cooler under the car takes the heat out.

Unlikely it has made it to 200k without the additive being refilled, it usually needs doing at around 80 - 100k

We bought the van with 115k on and its currently on 199,650 so any day now for a refill then. Is it DIY to refill the tank?

[RichardW]

You can refill the tank DIY but you need a diag tool to reset the light.

[Peter Palmer]

Great, I've got the lexia/diagbox on my laptop, used it to program keys etc in the past.