I have always been led to believe that excessive idling is bad for a diesel engine especially as it will encourage higher rates of carbon build up because of being under a light load. Also modern diesel engines like the CR unit can be up to 50% efficient, i.e. 50% of the energy in the fuel is converted into energy for propulsion. That means less energy is converted into heat and the car will take longer to warm up. In really cold conditions in a modern diesel car, if you were to let the car idle from a cold start then it is very doubtful that the water would reach operating temp let alone the oil, the heat rejection from the block and other surfaces would more than compensate for the heat produced by combustion at very low load levels.

What I do is like a few others have said, start the car, put seat belt on and then pull away gently and drive the car steadily until it has reached operating temp. Most of the wear that occurs in an engine happens in the period when starting from cold so the quicker that period is finished the better.

Ian

It may not help dpf if not followed by a decent run. what I do is stick a fan heater in my car 10 mins before I leave then she is toasty and ready to go when I am, and usually dry on screen and roof etc too

That's what I do if it's very cold - uses a few pence worth of electricity (even at today's grossly inflated prices!) - enough time for a cuppa and slice of toast , saves about the same few pence worth of De-Icer too.

In my opinion it's not wise to leave the engine ticking over to defrost the screens, not least because if some @rsehole decides to drive off in it whilst your back is turned then I reckon that your insurance company will be less interested than a very disinterested insurance company (not a rare beast!).

Secondly, your engine will reach a safe working temperature much more quickly if driven off sensibly at modest speeds rather than being left at tickover - that may warm up the engine oil but the transmission oil will still be cold.

Not looking forward to winter!

Dave

Your doing it absolutely no harm by letting it idle and anyone who says otherwise is just an idiot

Nice, it's one thing to voice your differing opinion but to call everyone else who dares to disagree an idiot?

Having a bad day?

Starting the car and leaving it to idle whilst scraping ice of the windscreen is fine, leaving it ticking over on purpose thinking your doing the engine a favour is misguided.

Just get in and rag the arse off it.................

.................that's the tractors and telehandler on the farm. With the car I'm a bit more circumspect but then I rarely give it 'death' at any time TBH. Tend to drive off as soon as but obviously if the screen is misted up I'll wait till it's cleared.

It only says this as a 'nod' to the environment, it even has the little flower logo next to it, like an eco friendly tip.

I always let i car idle for a to up 3 min depending on the outside temp. Your doing it absolutely no harm by letting it idle and anyone who says otherwise is just an idiot

Hmmm, on the basis that:

1) The majority of people in this thread appear to agree that idling is either unnecessary, damaging, or both,

2) A bit of research shows most manufacturers warning against letting your car idle whilst cold,

3) Opinions against idling are backed up with reasons,

4) your opinion is backed up by nothing other than scorn/insult to anyone who doesn't agree with your (IMHO) outdated misconception,

I think I'm going to conclude that you're pointing the 'idiot' finger in the wrong direction......

Edited 18 October, 201213 yr by mr_awol

I think it depends on your perception of immediately & how long the car has been sitting with the oil slowly draining into the sump for. When it's stone cold my old deisel will clatter badly for the first 30 seconds or so & then get quieter for the next 2 or 3 minutes of driving. Surely it's only common sense not to rev it during those first 30 seconds & then gradually increase the revs as the engine warms up? I do actually drive my cars after about 5-10 seconds of starting first thing in the morning but only to manouver out of the parking area at tickover on the flat. If the weather is very cold, I'll leave the engine running whilst I close the garage door but always drive off gently. If you want to sit there on a cold morning trying to demist the car with the engine running that's personal choice. Personally, I don't see that it does much harm but I do see it can do harm to rev a stone cold engine before the oil properly circulates. I had a friend once back in the day whose sister would always start the car with her foot hard on the accelerator & revved it right up as it fired, then revved it loads more for a few seconds before driving off. Used to make use wince!

I have also read that the difference between identical engines that use oil excessively & those that don't may well be wether they were run in or not. I personally think that gradually increasing the revs on a new engine over the first few hundred miles is the same mentality as not driving a stone cold engine hard. It's just showing some respect for your engine. My mechanic friend tells me that not revving the engine hard when cold can help the headgasket on some engines too as alloy changes it shape at different temperatures & you don't want it changing too fast or something?

Idling is bad for everything, particularly diesels. Very few diesels will actually reach operating temp if left idling in the cold.

Very few people live in areas where they can thrash the car to high speed immediately on driving off. By the time you have got out of your driveway/garage/parking building, onto the side roads and then onto the main roads the engine is ready to work.

The first thing that causes rapid wear and stress to a turbocharger is simply starting the cars engine and driving off. Today's car is a very sophisticated machine that is very easy to operate, just turn the key, drop it into gear and you are on your way. There are hundreds of things that happen in a matter of seconds from the time you start the car, and one of the most important is the flow of oil coming from the oil pump to the turbocharger. When your engine is first started, there is a very slight delay until the oil being pumped from the engine's oil pan reaches the turbocharger. In that amount of time, the turbocharger is already spinning many times faster than the engine. We know that the oil is the only lubricant for the turbo, so it is very important that it is being delivered quickly and efficiently to keep from damaging the bearings in the turbocharger. In this critical time, it is best to allow the car to idle for at least 3-5 minutes before driving off for the first time that day. Afterwards, if the car is left sitting for less than 3 hours it is OK to reduce this idle time down to around a minute. The reason we want to do this is very simple, oil temperature. When the oil temperature is cold from the engine not operating over some time, it is thick and slow to flow through all of the oil passages, lines and filters found in the oiling system. Slow moving cold oil cannot get into all of the passages and clerances found in a turbocharger, and because the turbo rotates at a very high speed the damage caused by the lack of oil flow happens very quickly. The ideal temperature for oil to flow and provide proper lubrication is between 180-210* F, and on a cold day it can take an engine up to 20 minutes to reach this oil temperature. Once you have let your car warm up for a few minutes, it is best to drive your car easy for at least the next 5 minutes, avoiding giving the car more than 1/4 throttle. This will give the oil time to properly warm up and do its job of lubricating all the vital areas of your turbocharger.

Slow moving cold oil cannot get into all of the passages and clerances found in a turbocharger, and because the turbo rotates at a very high speed the damage caused by the lack of oil flow happens very quickly. The ideal temperature for oil to flow and provide proper lubrication is between 180-210* F, and on a cold day it can take an engine up to 20 minutes to reach this oil temperature. Once you have let your car warm up for a few minutes, it is best to drive your car easy for at least the next 5 minutes, avoiding giving the car more than 1/4 throttle. This will give the oil time to properly warm up and do its job of lubricating all the vital areas of your turbocharger.

Which is exactly why you shouldn't leave the car to idle. The longer it is at idle the less likely the oil is of warming up enough for the oil pump to feed it to the turbo.

If you drive off straight away the oil warms up much quicker resulting in more effective lubrication.

If what you are saying is correct the turbo will be starved of oil immediately after a cold start in both situations (sitting at idle and driving off straight away).

The most effective way to get the oil up to temperature on a diesel is to drive it, not leaving it sat on tickover.

Which is exactly why you shouldn't leave the car to idle. The longer it is at idle the less likely the oil is of warming up enough for the oil pump to feed it to the turbo.

If you drive off straight away the oil warms up much quicker resulting in more effective lubrication.

If what you are saying is correct the turbo will be starved of oil immediately after a cold start in both situations (sitting at idle and driving off straight away).

The most effective way to get the oil up to temperature on a diesel is to drive it, not leaving it sat on tickover.

agreed you said at tickover the turbo is already spinning many times faster than the engine, so if it can take longer to reach running temp when idling then thats longer before the oil is able to travel well, meaning a turbo that is spinning for a very long period with out sufficient oil flow. All the more reason to drive off after just a minute but keep revs low and throttle light

The first thing that causes rapid wear and stress to a turbocharger is simply starting the cars engine and driving off. Today's car is a very sophisticated machine that is very easy to operate, just turn the key, drop it into gear and you are on your way. There are hundreds of things that happen in a matter of seconds from the time you start the car, and one of the most important is the flow of oil coming from the oil pump to the turbocharger. When your engine is first started, there is a very slight delay until the oil being pumped from the engine's oil pan reaches the turbocharger. In that amount of time, the turbocharger is already spinning many times faster than the engine. We know that the oil is the only lubricant for the turbo, so it is very important that it is being delivered quickly and efficiently to keep from damaging the bearings in the turbocharger. In this critical time, it is best to allow the car to idle for at least 3-5 minutes before driving off for the first time that day. Afterwards, if the car is left sitting for less than 3 hours it is OK to reduce this idle time down to around a minute. The reason we want to do this is very simple, oil temperature. When the oil temperature is cold from the engine not operating over some time, it is thick and slow to flow through all of the oil passages, lines and filters found in the oiling system. Slow moving cold oil cannot get into all of the passages and clerances found in a turbocharger, and because the turbo rotates at a very high speed the damage caused by the lack of oil flow happens very quickly. The ideal temperature for oil to flow and provide proper lubrication is between 180-210* F, and on a cold day it can take an engine up to 20 minutes to reach this oil temperature. Once you have let your car warm up for a few minutes, it is best to drive your car easy for at least the next 5 minutes, avoiding giving the car more than 1/4 throttle. This will give the oil time to properly warm up and do its job of lubricating all the vital areas of your turbocharger.

That's rubbish.

Anyone who has removed or refitted a turbo knows the oil lines stay full, as does the bearing housing and all pasages/filteres/lines throughout the engine. It takes weeks of being open to the air for a turbo to stop dripping oil. As soon as the oil pump turns, oil is pushed out the end into engine bearings and the turbocharger bushings. Further turbos will spin for a long time on a film of oil before doing themselves damage. Did you know that turbos are spun up to speed and balanced with no pressurised oil supply.

Turbochargers do not care about oil temperature, provided it isn't too hot. They do a very good job of heating oil themselves.

3-5 minutes is un-necesary and wrong. Your turbo is ready to go as soon as your engine has oil pressure, that's usually before you have it in gear.

Well all I have to add is that modern cars have built in ecu restrictions that take account of oil and water/coolant temps and will restrict performance until operating temperatures are reached. Also making sure your windows are clear is a safety point, so by the time you have cleared the screen,done the side windows and switched on the rear defrost......will be more than enough time for the fluids to start circulating to drive normally. Modern oils of the 5w or 0w type will still have enough viscocity to protect your engine when cold. With our cars electronic ( fly by wire) for the budding top guns out there :-) it's hard to really thrash your car if it's not ready. Many a hire car has tested out this. Shhhhhh don't tell.

A car has a design temp, the sooner it reaches that the better it is. We also know that cars wear badly if ragged from cold so the common sense head shown by most here works, For me on a warm day start the car, pop on your seat belt which gives a few seconds for fluids to move & then drive off gently until the car is up to temp. On Skodas if you have maxidot use the oil temp as a good guide. If you only have the normal temp gauge allow 3-4 times as long as its taken to get to temp before assuming enthusiastic driving can be commenced. On a cold frosty morning or a damp morning where the screen is misted up then let the car warm whilst you clear the screen, it wont hurt it that much & its nice to see where the accident may happen before it does

If you only have the normal temp gauge allow 3-4 times as long as its taken to get to temp before assuming enthusiastic driving can be commenced.

Really? that would be around 50 miles on a really cold morning!

My 170 CR Diesel takes 35/40 mins to reach 90 degrees oil temp from cold in the mornings that doing 3 miles A road to motorway then 18 miles on motorway(65/70) then 2 miles A road again it just about makes it to 90 degrees before reaching work, water temp reached in bout 15/20 mins.

Lee

My 170 CR Diesel takes 35/40 mins to reach 90 degrees oil temp from cold in the mornings that doing 3 miles A road to motorway then 18 miles on motorway(65/70) then 2 miles A road again it just about makes it to 90 degrees before reaching work, water temp reached in bout 15/20 mins.

Lee

Yep probably the same for me, takes the 2 miles to get to mway to reach 50degC, and about 15mins down the m/way up to the normal 94degC ish, in a cold winter longer. Price to pay for a more efficient diesel I guess.

My 170 CR Diesel takes 35/40 mins to reach 90 degrees oil temp from cold in the mornings that doing 3 miles A road to motorway then 18 miles on motorway(65/70) then 2 miles A road again it just about makes it to 90 degrees before reaching work, water temp reached in bout 15/20 mins.

Lee

Should follow the advice of some on here and idle it until its warm. Should only take 3-4 hours.......

Should follow the advice of some on here and idle it until its warm. Should only take 3-4 hours.......

Better still to comply with said people, the engine is better to be left on all the time, negating the cold start need and never allowing ice to form. Ill do that tonight, be one heck of a smoky set off in the morning if i did that with my old bus.

I wonder how the electric turbos that are to be fitted to the next gen twin turbo (one being spun by an electric motor)Audis will stand up with cold starts etc.

http://www.autocar.co.uk/car-news/motoring/audi-reveals-electric-turbocharger-technology

Sent from my iPhone using Tapatalk whilst in a taxi rank

Edited 19 October, 201213 yr by jonnie5

After reading all the points made in this forum i have decided that the best way to warm up my car from cold is to :

1.Put brick on throttle pedal, making sure its right down into the floor mat.

2.Start the car.

3. Go and have a cup of tea and a bacon butty (sandwich).

4. Check temp Guage has moved.

5.Collect all engine parts that have come out of the exhaust pipe.

6.Sit inside nice warm car and cry until cold again.

7. Repeat as required.

Isn't this why we have multi-grade oil? :| :|

I was taught that the best way to warm an engine up was to use it. My gauge is on 90 within 5 miles / 7 minutes. Straight up the road on to the motorway, hit 60mph and stay there.

For me, it depends totally on whether the windows will stay clear without needing to be warmed up (by the heater blowing hot air). This will be my first winter with my Octavia, so perhaps it will be more efficient at doing this than my previous car - I suspect it still won't be as good as my 1996 Ford Escort with a "QuickClear" screen was!

I always find that the screen clears much quicker if it actually clean. A damp cloth soaked in washing up liquid and water seems to work best, and dried with newspaper.

When I start car (2.0tsi) revs are about 1100.....I wait until they drop to 900 which take up to one minute and then drive off.

It only says this as a 'nod' to the environment, it even has the little flower logo next to it, like an eco friendly tip.

I always let i car idle for a to up 3 min depending on the outside temp. Your doing it absolutely no harm by letting it idle and anyone who says otherwise is just an idiot

In which case I am an idiot!

Most engine wear occurs when cold. An engine left idling in sub zero temps will take quite some time to warm up, especially a diesel. If it isn't doing any 'work' then it won't warm up.

The advice is drive off but don't drive hard until up to temperature.