aeggroup

Hi.

Do you guys warm up your diesel engine at morning before driving ? Do I have to do it ?

Thanks.

05e320cdi

I have never warmed up any car and a diesel will take forever to warmup at idle. I would suggest driving it right away and just like any other engine, don't beat on it till its warm.

Carsy

+1 . Idling when cold will increase engine wear .

Snipe656

I have always let my truck and old Mercedes idle until they warmed up when it gets cold down here. I suppose it has added some extra wear but both have just over 200k miles and can't say either has any engine issues at all. My BMW I just get in and drive though but more so because it has a newer style heater that works instantly where the other two vehicles don't.

zemun1234

If your profile is correct, you are in Houston and cold there is not same as cold in Chicago

As for my self, I let RPM to drop ~ 800 RPM before I start driving it and usually I use same routine - put seatbelt etc ...In general, warm up is not above 30 sec (on very cold morning, it could be close to 1 min).

Snipe656

True but I still let them idle probably upwards of 30 minutes in the morning before I leave. For the truck I do it year round, either to get the AC going good or the heater. This though is just morning routine stuff, end of the work day in any of them I just fire them up and go(usually before my seatbelt is even on).

EdzBenz

I let mine idle in cold weather for about a minute or so. There's no scientific reasoning to this. But, I feel it is enough time to heat the oil a little so it lubricates the engine better than at start up. I think synthetic oil needs less time than standard oil. I also don't go over 2800 RPM until my temp gauge starts to move on the dash.

aeggroup

I used to warm up for about 5-7 minutes, but according to all of your answers - I think I don't need to do it. I think 1 minute is enough.

Thanks to all.

harkgar

Everything I have read is against morning warming up, particularly diesel engines.

Snipe656

What have you read to be the problems if you do morning warmups? Just curious because as I said I have done around 30 minute warmups since day one with my truck and regardless of outside temps and at now 202k miles it has yet to display any issues. I do similar methods with the old Mercedes though more I think about it not as long. But when it is actually cold outside my truck would be like trying drive an 8k pound vehicle with an 40 HP engine, it has always been very cold natured.

u001elg

It is not so much "problems" with extended warm-up periods, just that it is not necessary.

You have the obvious objections of wasted fuel without propelling the vehicle anywhere, additional wear through engine operation, potential dilution of oil (fuel & moisture) due to operating the engine for an extended period while cool, etc. I can also give the opposing point that I have 409,000 miles on a GM 6.2L that does not seem to have lost any lift without a warm-up period.

With that said, I personally don't use a "warm-up" period simply because a diesel does not make much heat unless it is working. By driving gently right after start-up the engine heats up faster and achieved proper operating temp sooner. I fully admit not shutting off my diesel during extreme cold (spent some time in Green Bay, Wis and Lake Wadena, Minn) when the daytime high temp was -23 deg F. Just let the vehicle idle until I returned to a more hospitable temperature.

With that said, my challenge to the gentleman from Houston is what are the myriad of advantages to letting a vehicle idle for 30 + minutes in a warm climate?

Snipe656

Simple, during the times it is cold outside it pre-heats the interior of the vehicle and the times when it is hot outside it pre-cools the interior of the vehicle. I'd rather let the thing idle out in my driveway for 15-30 minutes, maybe less(honestly never timeed it but I know it is awhile before I get back to it) and come out to a comfortable vehicle than to start it right up and have to drive 3-4 miles before it becomes comfortable. More importantly I'd rather not deal with the kids pissing and moaning about the comfortable feeling of the vehicle. I am estimating the 3-4 miles, I know for a fact it is not comfrotable until I reach the main road and it is 2 miles just to get out of my neighborhood plus I am guessing another 1-2 miles before I hit the main road. It never has seemed to hurt anything on any of the vehicles I do that on and if all it is noticeably doing is burning some extra fuel then so be it, I could care less on extra fuel consumption.

The current MBZ does not have 100% AC so in the hot months I let it cool down some before starting the day. The heater in the current MBZ does not work so I do not bother waiting for something that never is going to happen. The prior MBZ had working heater/AC and I did let it warm up. I do not do it at all in the BMW, it has the ceramic pre-heater and its AC is more than efficient plus I do not park it outside which helps interior temps as is.

Regardless of if the vehicle is gas or diesel powered, I still do the same thing. It is part of my morning routine that I start whatever I am driving at the same certain point of the morning then I continue doing other things before loading people into it and actually driving. I do not typically do it at any other points in the day unless the weekend perhaps and leaving the house midday with everyone.

BTW my diesel truck's owners manual actually outlines warming it up via idling in cold weather. It defines the temperature and is a temperature that is actually reached down here because I have experienced it. It goes on to explain how it will do a high idle to help warm things up, I think it might even be doing a load somehow on the engine because it sounds like it is. I do not remember the details beyond that because honestly not read the owners manual in several years. I do know the only way it can engage for me is if the vehicle is idling in park with your foot off the brake and it is I think below freezing outside.

u001elg

I now understand...

The extended warm-up is for your personal comfort and part of a morning routine.

I think we can both agree that an extended warm-up period is not necessary for normal vehicle operation.

AsianML

Same discussion going over on the W203 AMG forum. Same thing applies and even more due to the inherit nature of a diesel engine. Idling is the most inefficient and slowest way to warm up a car and/or engine, moreso in a diesel. Cold starts and cold idle are also the times when the most wear occurs in an engine. By idling a cold engine for extended periods of time, you're subjecting the engine to the higher wear for an even longer period of time.

By doing an idle warm-up you're also neglecting transmission and differential warm up. If you think you can warm up the engine, coolant, and oil to temperature and then just beat on it right away, you're wrong. You'd be subjecting the trans and diffs to a lot since those haven't been warmed up yet.

Quickest way to warm up an engine/components and the vehicle heater is to drive it. Heat is just logical since heat comes from the engine.

https://mbworld.org/forums/5011119-post26.html

Snipe656

The point I was originally trying to make is it seems to not have any noticeable negative impacts on any car I have owned. I typically keep my cars to close to 300k miles and only had one that had some engine issues(some blow by right at 300k). Most people do not even seem to keep cars to 200k and a lot of modern cars cost way too much to fix things by that point in usage. So my personal opinion is a car becomes to troublesome or expensive to keep LONG before any engine issues come up.

u001elg

And the point I am making is that a warm up period and especially an extended warm up period is just not necessary. That is the question originally asked by the first post.

I defer to your empirical determination that no detrimental effects are noticed, but then I also note that vehicle manufacturers list extended idling as "severe" service with more frequent maintenance requirements. The other posts stand for themselves as to the more specific effects of extended idling for no purpose.

I am certainly no tree hugger, but I am not about to burn up any additional fuel, within my means of control, just to idle a vehicle.

Snipe656

And someone else I thought posted that it is damaging, which I recall is what sparked me getting into more details of what I do and no damages.

ImInPA

Todays engines are made to such fine tolerances compared to engines of 20 years ago that much of the traditional thought no longer really applies. Years ago, it was a common practice to let gasoline engines idle during the winter months to get the car's interior warmed up. Today's electronic engine controls bring a gasoline engine up to temperature much more quickly. Diesels of yore could take forever to produce heat to the heater core due to the inherent thermal efficiency of a diesel engine. Today's diesels usually have an auxiliary ceramic electric heater core to produce interior heat quickly. In the case of my W212 Bluetec, I believe it is a 1000W ceramic element. That said, the engines tolerances are so accurate and balanced, I do not think it makes much difference to the engine if you idle it or just go. I do not know what, if any, issues would occur to the transmission. My guess is that the transmission would suffer no ill effects either. Just do what makes you feel better.