Diesel car idle during week, issue during cold spells?

mrcheez · 15-11-2019 1:53pm #1

I have a 2018 1.2l diesel car, bought during the summer.

I don't use it mid-week as I don't use it to commute to work at the moment, but if I'm leaving it idle for a week or two do I need to run it during spells of frost/snow, or is there no damage just leaving it sitting there?

It's maintained perfectly and has anti-freeze etc.

CiniO · 15-11-2019 2:16pm

No need to run it during cold spells.
Just run it when you need to use it.

If battery is not great or electric current drainage in the car is higher than normal, then it might drain the battery though during that week or two though.

If that occurs, you might consider disconnecting battery during period of non-use.

zilog_jones · 15-11-2019 3:25pm

My only concerns would be the battery and the fuel.

Might want to get a battery maintenance charger if you're regularly leaving it for multiple weeks, or disconnecting it if it's not too much hassle (might lose some settings, clock, etc.).

Diesel has a "gel point" where it starts to become solid - if the diesel in the tank is from the summer you could potentially run into trouble trying to start it at temperatures below -5 degrees C, but they change the formulation for the winter (in November?) so it should be good down to -15. Temperatures below -5 aren't too likely in Ireland, but not impossible either.

mrcheez · 15-11-2019 3:35pm

it'd mainly just be idle for 5 days typically... might do an occasional mid-week shop.

Usually when I DO drive it, I give it a long run because it's diesel. So I would normally never use it for short trips beyond the mid-week shop.

Battery is new so should be fine.

zilog_jones · 15-11-2019 3:48pm

Battery will probably be OK but you could get unlucky. Some modern cars have problems with parasitic drain, especially if they have keyless entry.

mrcheez · 15-11-2019 3:58pm

so there's no need to turn it on and let it run in the driveway for several minutes every 2-3 days during freezing periods?

zilog_jones · 15-11-2019 4:12pm

I think it would be a waste of time and fuel. You'd need to run it a good 15 minutes or so to recharge the battery to make up for what you used to start the engine. Using the car once a week shouldn't really be a problem.

If you're concerned about the battery, get a multimeter and check the voltage regularly.

CiniO · 15-11-2019 5:17pm

mrcheez wrote: »

so there's no need to turn it on and let it run in the driveway for several minutes every 2-3 days during freezing periods?

I'd say starting it to let it run for several minutes on the driveway would do more harm than good.

Cars are perfectly capable to be left unused for few days.

biko · 15-11-2019 6:23pm

It should be perfectly fine unless there is some hidden issue.
Take it for spin until it's nice and toasty inside a couple times a month to blow off the cobwebs.

TheBoyConor · 15-11-2019 6:31pm

better off not running it just for the sake of it. You only get condensation into the engine and clog it up with soot as it never gets to warm up fully if you just give it a tip around just for the sake of it.

As for the fuel gelling? Where do you think we are? The Eastern Front in 1941? We don't get that sort of cold here. Anyway, running the car isn't going to make a difference or heat up the fuel tank.

zilog_jones · 18-11-2019 10:46am

TheBoyConor wrote: »

As for the fuel gelling? Where do you think we are? The Eastern Front in 1941? We don't get that sort of cold here. Anyway, running the car isn't going to make a difference or heat up the fuel tank.

We're not talking about petrol here. The "cloud point" (where it starts to solidify) of summer diesel sold in Ireland AFAIK is 3°C, and the "Cold Filter Plugging Point" is -5°C - this is a standardised measurement that is supposed to be the minimum temperature where it flows at an acceptable rate, but some tests show the CFPP is too low for modern diesels in cars. These temperatures aren't outside the realms of possibility in Ireland.

For winter diesel it's -5°C and -15°C respectively.

My point is that since they're not driving the car that regularly, they could potentially run into trouble if there's still mostly summer diesel in the tank.

mrcheez · 18-11-2019 11:34am

zilog_jones wrote: »

My point is that since they're not driving the car that regularly, they could potentially run into trouble if there's still mostly summer diesel in the tank.

I filled the tank last week so probably not.

As I mentioned before, when I DO drive the car, I drive long distances, hence the reason for getting it.

It's not a means for daily commuting.

zilog_jones · 18-11-2019 12:00pm

I meant more not doing massive mileage and not filling regularly, but I guess it's not a problem in your case.

Diesel car idle during week, issue during cold spells?

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