Insane fuel consumption!

My FL1 Td4 06 have used a bit to much diesel the last days. I set the trip counter at 0 when I filled ut the tank, have now driven about 100km and used half the tank!
I cannot see any leaks, nor does it smell diesel either. So where does the diesel go?
I have i knocking sound coming from the pump by the right rear wheel, can this be related?

Have you checked your oil level? If it has risen, I believe the HP pump on the TD4 can leak into the sump via the chain cover/housing.

If so - obviously be very careful using it.

As above, although the sump won't hold 50 litres of diesel.

I'd refill the tank and check the fuel has actually gone, and it's not just a level sensor issue.

Check the fuel rail return pipe back to the tank. You may be squirting the juice down on to the road instead of back to the tank.

Thanks for the replays folks Just checked the oillevel, its on the topmark, as it should be so no diesel in oil then, and I filled up the tank this mornin, 33,8 liters! and driven 104km!
Will check the returnline next! But I have tried to see under the car when engine idling and could not see any fuel dripping. If thers a leak it will come out when driving? caus the higher rev?
Thanks so far!

I'm thinking it's got an injector that's spraying all the time. Is it running ok? Is there lots of smoke from the exhaust?

Its running ok, no smoke. A little bit uneaven when cold but quite normal and pulls ok!

Might be a fuel leak, but only when the engine is cold or warm, or perhaps when revved.

The HP pump can leak when cold, but stop when it’s warm, for example. Or perhaps a damaged fuel line that sprays only when pressure is high enough.

Ok, so then I`ll keep on looking for leaks, must be wet around somewhere then!

To loose 30 odd litres of fuel in 100 kilometres is a lot. If it's dripping out of somewhere, it would be very obvious. It's a bit of a mystery really.

My HP pump has been weeping for a bit. Not much, but enough to dampen the under tray. I've not had any noticeable drop in MPG.

I also have a sound from the engine when increasing speed, like a fan that goes on fullspeed? a friend suggested it may be a hose to the turbo? But cannot see anything wrong.
If this "fan"sound is the turbo, then could this cause the extra fuel consumption?

Landrange said:

I also have a sound from the engine when increasing speed, like a fan that goes on fullspeed? a friend suggested it may be a hose to the turbo? But cannot see anything wrong.
If this "fan"sound is the turbo, then could this cause the extra fuel consumption?

Click to expand...

Aha! Whooshing on acceleration is almost certainly a split turbo hose. Check them all, especially the elbow before the EGR. You have to feel the pipes, as a split might not be very noticeable.

Ok, next check then is the hoses obviously! Thanks lads!

Hav now driven some kms and filled up again but now the consuption is about normal! Have no idea what this was all about? Have checked the turbo/intercooler hoses, found nothing wrong. The whooshing sound is gone and it pulls ok.