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Should I 'warm-up' my Car before a run?

20K views 33 replies 19 participants last post by  frans-c 
#1 ·
Although there are no severe winters or snow where I'm writing from, I still wanted to know if I should turn my car on and warm it up for a couple of minutes before use? Or is it ok to just start it and get going immediately?

There's no engine temperature meter on the dash, so there's no way I would know.

Also - what about in 50 degree celsius summers? Is a warm-up still needed?

Car in question: 2002 A-160 :thumbsup:

Thanks in advance! :)
 
#4 ·
Warm it up

You should definitely warm it up for at least a couple of minutes before driving it. I know MB uses synthetic oil but the oil still settles after sitting overnight and it is always recommended to allow the oil to do 2 things prior to driving: 1) recirculate back through the engine and 2) warm up to close to operating temperature. I'm not saying that you're going to destroy your car by not letting idle for a couple of minutes but it idles high for a reason when you start it after sitting overnight. When your car's idle starts to settle back down to it's normal rev range that's it's way of letting you know that the oil and coolant and everything else is now ready for driving.:thumbsup:
 
#7 ·
I start, let the idle drop, and then go. Allowing the car to sit and warm up loads up the cats ("load" as in KILLS the cats) and it delays the process of bringing the oil up to temp. The oil temp is what you’re concerned with. Mobil1 0-40 synthetic oil, although much better than dino juice, has a thickness of about 40 cS at 75F. It needs to get to 10cS as soon as possible. I keep the revs under 3K for the first 5 miles to ensure the oil has thinned down to where it should be. Starting a car and allowing it to idle will take forever to bring the oil up to 200F+ AND while waiting, wear will occur.
 
#12 ·
Musikmann said:
Sorry Marcus, but what is cS? I have never seen that abbreviation for any units of measure, but I assume it you mean viscosity?

Thanks in advance.
The thickness of moving oil is actually measured in hundredths of a Stoke or cS (or cSt, depending on the manual). It's the manner in which viscosity is measured. Rather than saying a certain oil is more viscous than another, cS quantifies it. 0-30 weight, 0-40 weight, 10-30 weight, 20-50 weight, and even straight 30 weight all have the same viscosity at 212F. If you say that to someone, they think you mean the oils are close. In reality, they all have the exact same viscosity: 10 cS, which is good for minimal wear. One of the reasons MB states to use "approved" oils is the cS of the oil at various temperatures. Like I posted earlier, Mobil1 is too thick at 75F. It's 40 cS. However, I've seen write ups that show some brand name 10-30 dino juice as being over TWICE as thick as Mobil1 at 75F. They're both 10 cS at 212F, but there's a lot less wear during warmup when the approved oil is used.

Here in southern California, Ferrari dealers used to GIVE customers AGIP brand oil. Why? Because they felt it had the best cold cS rating. Hollywood Sports Cars (no longer in business) used to tell customers to NEVER use anything else and to get the car moving as quickly as possible. That was to bring the oil up to temp.
 
#15 ·
MarcusF said:
See what happens when I'm asked a simple question? That's why they put me in an office. Put me in a cubicle and I'm likely to blather on all afternoon to all the other cube dwellers. Like that post where the guy asked what a 211 was . . . . .DAMN. It's that red light again! I'll have to get back to you later.
Haha, please don't apologize! I can't speak for anyone else, but when I ask a question, I'd much rather hear a thorough answer, than a quick blowoff, like "where have you been living, in a cave?" :)
 
#16 ·
Thankyou for all the answers. Much appreciated info! :thumbsup:

2 points noted here which I experience as well:

  • The Engine "idle" is a little louder than normal on starting the car early morning. This I note because I start the car w/o even entering it i.e by standing outside and turning on the engine w/o even a little push on the accelerator. I then set my stuff in the back seat. This louder than normal idle probably is an indication that it needs a little warm up, before it is back to its normal quiet and smooth self after a couple of minutes.
  • During the drive, the automatic 'gear-change', as someone mentioned, is also delayed if there's no warmup.
Moral of the story: Will warm-up the engine for a couple of minutes from now on - Have to wake up 2mins early :crybaby2:
 
#18 ·
Letting the car idle for too long is considered a "severe" driving condition. Many automobile user manual states that.

I've heard that when the engine is idling, the gas/air mixture was not burnt thoroughly and can cause carbon buildup.

Some say that for modern fuel injection engines, it's not good to warm up and not necessary.

Does the MB owner manual tell us to warm up the car? or does it tell us not to?
 
#21 ·
Warm-up & Owner's manual

cerritos said:
Does the MB owner manual tell us to warm up the car? or does it tell us not to?
I remember reading about the break-in period for the 1st 1000 miles, but I have not seen what they say about warm-ups. There is bound to be something in there hidden amongst those 300+ pages though ;)
 
#22 ·
Here's my story. When I start my 1998 C230 (68K miles) first time after sitting overnight I can hear a "high pitched whine" coming from the engine compartment. I am told that this is a turbine injecting air into the exhaust to bring the cat up to temperature. If I start the merc and pull straight off then there is the obligatory delay in gears shifting up. That is each gear is held longer while the cat is warming. Eco and all that. However if I sit and wait for the turbine to shut down (...and it does after exactly one minute.) and then pull off the gears shift normally. That is there is no delay. Check it out folks.
 
#23 ·
Than again, I might have warmer weather presently in CA, but using the computer-controlled starter, I click the ignition and while the computer is cranking the engine, I am buckling up and shifting the gear.
Usually from the time the engine fires up to the time I start rolling takes about 1/2 seconds.
In the past in 4-seasons I was giving the engine few seconds to warm up. That was mostly due to fact that primitive chokes of the era would stall the engine if the gas was pushed on cold engine. Even than I learn to start rolling on the idle, and giving the gas at the 1st to 2nd gear change.
Idling cold engine supposable is washing the oil from cylinder walls, costing accelerated wear-out. The truth is, that even if that is the truth, from expected 300,000 miles life expectancy you might only get 280,000.
This way, or another my gasoline engines takes 2 miles of highway driving at 65 F to get to operating temperatures. I am not to waste my time and fuel waiting on the driveway.
 
#25 ·
My tranny wouln't shift if i don't warm it up before use. keep in mind that I have a old mercedes.
 
#26 ·
Diesels present on US market are old technology and are generally under-powered. That makes warming up a bit more critical, but the 1/2 sec from start to rolling apply to our E300D as well. Maybe not exactly, because this engine doesn't have computer control of the starter and I actually have to waste (!) the time holding the key turned.
Things look a bit different on big rigs. My motorhome has air suspension and air brakes. It will not go, till the system is pumped to minimum of 60 psi, while operating range is 100-120 psi. Therefore after long parking, when the air pressure drops to 0 I have to run the engine for few minutes to pump the air.
I hate the wait, so I have installed electric compressor on board and when I have eclectic power -I pre-pump the air, what lets me to start rolling the rig just seconds after starting the engine.
 
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