In the opinion of the local diesel experts here, does letting your CTD idle for several minutes to warm up on cold days/nights affect the sensors? Is it a bad thing to do considering the emission issues associated with this car?
Letting a diesel idle for too long is never good for it, no matter what type of engine it is or what type of car/truck it's in. However, it needs to be warmed up before you head out with it. I let mine idle for about 5 minutes in the morning when it was extremely cold last winter (-20 or lower Celsius).
I rarely let it idle long. I prefer to start let it run for maybe 30 seconds, then get going albeit slower throttle. Mine is in garage so this morning it was 47 in garage when it was 22 outside. When it sits at work I don't let it idle, don't see any point really. 20,700 miles no emissions issues yet, fingers crossed.
After turning the key, I'm in gear and rolling within seconds. I do take it easy on the throttle though. Where I live in a subdivision, it is easy to loaf along until I get to a larger road where I have to go faster. Besides, the dogs like sticking their heads out the open windows when I'm going slow. One dog out each side.
Not sure if it applies to the Cruze or not, probably does, but when I had my 2007 Jeep Grand Cherokee diesel, it said something in the owners manual about not letting them idle cold due to incomplete combustion and fuel getting into the oil.
That was likely due to the methods Chrysler was dealing with emissions at the time... If I remember correctly at least on the Dodge Ram Diesel Trucks they were not using DEF and were basically overfueling to clean the DPF which lead to rising oil levels since a lot of fuel washed down the cylinder walls...
The owners manual recommends letting the diesel idle actually. I let mine idle frequently, I always remote start it. I do not notice any issues from it. As long as you are regularly changing your oil it won't matter.
One possible problem with warming the engine by idling it is that while the engine may be warm, the transmission and wheel bearings are not. A driver may then drive faster than the cold lubricants can handle. Warming everything up at once prevents this.
My only direct feedback to this is that one day early on in my ownership, I started my car on e very cold winter day (close to zero) and pretty much immediately got stuck in gridlock traffic. I kept it idling for 2 hours and the temp gauge never moved. I never had any sensor issues related to that.