Carsy

I welcome any advice for a friend near Boston who will winter his diesel over 6 months in the garage.

He wonders whether any precautions should be taken preventing the fuel in the tank from deteriorating over this length of time at this temp ?

Thanks.

JC

AdidasC230

Id empty the tank out and use a trickle charger. Thats what we recommend to customers at the dealer here who are snow birds.

Glyn M Ruck

JC - If the car is to be garaged its less of an issue. Minimum should be:

- Ensure diesel filters are new.
- Ensure no water in the fuel system.
- Fill tank with fresh diesel.
- Competely fill tank so there is no air gap.

This should suffice for 6 cold months.

Belt & Bracers approach would be to add a flow improver to prevent waxing/gelling & a biocide. Biocide is less important in new low sulphur diesel. Sulphur reducing bacteria are less of an issue these days & they can't survive in a dry system. They live in the water phase & take nourishment from the Diesel phase.

What Benz says regarding diesel additives & approved products:

Glyn M Ruck

Don't empty the tank - This means you would have to bleed the entire injection system from scratch on a diesel to prevent a dry start up of the pump & injectors. At the tolerances that Benz now runs their high pressure diesel systems and amplifier injectors any air in the system can do severe damage to both the pump & injectors on a dry start. This is why the latest Benz diesel cars are fitted with run-dry prevention technology.

Dealers

Carsy

Sounds to be good advice. Thanks Glyn.

I would also make sure to use the winter diesel formula for easier starting .

Glyn M Ruck

Yes - all oil companies make winter diesel as the temperatures start to head South.

Clean filters ensure little chance of blinding taking place on start-up after standing & obviates bug growth should the filter have trapped some live ones prior to lay-up.

listerone

Never heard of this.How does it work? I'm fairly new to diesel..only about 40K miles so far...but I *have* read that it's not wise to run out of diesel because doing so can require a mechanic to get things going again.It would be great if this technology you refer to would make it so running out of fuel in my car is no more serious than running out with a "petrol" vehicle.

Glyn M Ruck

To precis the article I have on the subject. Does not say from which model/MY it will be fitted.

"Run-dry technology on diesel models. The high pressure diesel injection system cannot tolerate air ingress for a number of reasons, including lubrication of the moving parts. This can easily happen if the vehicle runs out of fuel. To prevent damage to the system and a dealer fuel-system bleeding exercise, the calibration engineers employ a new strategy: at a predetermined fuel level (after the low-fuel warning light illuminates), a "misfire" reaction is introduced (by the ECU) to simulate the vehicle running out of fuel.

This is done by applying a cyclic waveform to the torque request received from the accelerator pedal. If this is not enough to force the driver (you vill ya!) to stop, a reduction in torque is applied until the vehicle comes to rest. Once stopped, the engine will be switched off by the ECU and not allowed to be restarted until the tank is refueled with a set amount - normally around three litres"

The driver would be unaware of the ECU induced mind game and be certain that he/she ran out of fuel. Luckily for the driver there is sufficient fuel in the system to prevent air ingress and, after adding fuel, the vehicle can be restarted.

You can just imagine the German engineer at DB sitting down & writing this in his best English! Excuse my quip in parenthesis.

Carsy

Interesting info. I don't suppose you have the models it affects Glyn. My engine is a 646.

I have run down to about 3 litres so it may not have this feature!!

The trouble is a different mindset develops ,ie, when the low fuel level lights illuminates you calculate that at your present consumption of eg 4.7 l/100 km that you easily have 150 km left to run !!

Oh well, I will have to control myself in the future.

Thanks for the info.

Glyn M Ruck

No JC - don't know models or MY. Will let you know if I find out.

Gashde

I'm now reading this with my diesel sitting in the garage with a almost empty tank, I hope the car do start tomorrow morning for me to make it to the petrol station