Idling a Diesel engine on cold start

[manisinghb]

Hi guys,

Apologies if a similar thread has already been opened elsewhere but because this is such a conflicting issue I thought I'd ask the question again, especially since the cold weather is upon us!

I have a 2008 Ford Mondeo, 2 litre diesel. My wife drives the car on a daily basis BUT she only drives it 6 miles each way, a brief commute for a diesel - I know! She was complaining of it being sluggish in the mornings, and making rattling noises. So I would start the car when I leave home (app. 15-20 minutes before her) and she said the car was driving amazingly!

However, recently a lot of family and friends and mechanics and internet forums have been saying this is bad or good on the engine, and I can't tell! So thought I'd get some more insight here...

 

[manisinghb]

I don't think leaving the car to warm up by idling is beneficial at all. A lot of the wear on an engine happens before it is up to temperature, and leaving it idling takes a lot longer to warm the engine than gentle driving. The manual of pretty much every car I have driven explicitly said not to leave the car idling to warm it up. It might run a bit better when warm, but it is a lot better to warm it up by driving normally.

Also, I don't know if that car has a particulate filter, but If it does I'd imagine it will clog up pretty quickly with that kind of use.

Yes has a particulate filter, been driving it to the in-laws to get a good run in to help clear it but obviously this is once in a blue moon. Is this the best way of clearing the filter - taking it for a 30 minute constant drive at 60mph+?

Also, I agree with all your points on the idling but my concern is that the 2 litre engine isn't warming enough by the time she reaches work 6 miles away, could that be having negative effects in any way apart from on the filter clogging?