Does this harm the engine?

[ES_TRADER]

From a cold start, drive like 20 feet and shut it off again? Then start it up, drive like 20 feet again and shut it off...

Im wondering because i do this frequently rearranging cars in my garage and for some reason feel guilty everytime I start up the m after it's been sitting for a week, only to shut it right off one minute later... Then back on again.

The manual states to start and set off immediately but what if you aren't going anywhere? Will
Doing this frequently harm the engine in the long run?

[FVM3]

I dont think so , i do this a lot

[kscarrol]

Well, cold starts cause the most wear and tear on the engine but compared to the two or three colds starts I do per day, your once or twice a week is likely causing less damage than my daily driving does...

[Gearhead999s]

It is not a good thing to be doing too it as you are loading the engine up with excessive fuel if you never fully warm it up between starts.This will put more contaminents in your oil and if done enough times it could foul your sparkplugs.

[SenorFunkyPants]

It will screw up your catalytic converter...all that unburnt/poorly burnt fuel from the rich start up cycle will contaminate it and eventually you will get an emissions fault.

[JCtx]

That first minute or two creates a lot of condensation that can rust internal engine parts as well as steel exhaust parts. Worst of all, that practice results in more than normal acid formation in the oil, which is neutralized by the additive package, but once depleted, can cause serious engine damage.

If you don't take the car for a 10-mile run (15 in winter) often, you need to change the oil a lot sooner than normal. And also charge the battery after starting the car for a minute or two; it discharges the battery substntially, plus remember a lot of things stay active on the M3 for 10 minutes or so.

[Seattle S65B40]

I have to re-arrange my car too and i sometimes roll it around in neutral so that I don't have to turn it on, or if I do, I will take it for a short drive to at least warm up a bit.

[Totti]

What about me? My daily commute is only 3-4 mins to and from work with a short 20 minute dispersed (10 mins up, half an hour later 10 minutes back) round trip for lunch.

Is that bad?

[G_Anders]

Dealer told me cold starts up are not good let it run for 5 minutes

[tony093]

why do u shut it off?
just let it run while u moving the cars around...

[elm3]

Originally Posted by tony093

why do u shut it off?
just let it run while u moving the cars around...

+1 just let it run for a little bit. It is better to let it run than shut off and re-start. I do have to re-arrange cars in my garage, but I always let it run for a little bit, while I'm moving my other cars.

[JCtx]

If you turn the engine on, you need to drive the car for 10-15 miles to evaporate all condensation folks. Another no-no is to just run the engine 'to charge the battery'; that's MUCH worse than leaving it off.
If you leave it running for a minute or five, the only difference is the latter charges the battery a bit more. Remember the M3 has 9+ liters of oil in there, so oil takes longer to reach operating temperature and evaporate all condensation. And more cold start-ups contaminate the oil a lot more too, due to the extra fuel. And no, the algorithm won't compensate for that, so you better change the oil much sooner than 5 digits; I wouldn't go past 5K with that kind of driving. It's brutal on oil.

For those 4 minutes away from home, just use a bicycle when you can (or just walk); your health will thank you for it... especially if you're not in great shape . It probably takes less time as well. Just saying.

[Silvertige]

Originally Posted by Gearhead999s

It is not a good thing to be doing too it as you are loading the engine up with excessive fuel if you never fully warm it up between starts.This will put more contaminents in your oil and if done enough times it could foul your sparkplugs.

I believe this is correct. Fouling the spark plugs is a definite concern in the op's described situation.

[Titanium Silver]

Absolutely not

[Totti]

Originally Posted by elp_jc

For those 4 minutes away from home, just use a bicycle when you can (or just walk); your health will thank you for it... especially if you're not in great shape . It probably takes less time as well. Just saying.

lol... Then I'd never get to drive it!

[goldminer]

The warnings about condensation are true. Gasoline has some sulphur in it and a lot of hydrocarbons. When you burn it you get water vapour and sulphur dioxide. You also get oxides of nitrogen due to the nitrogen in air. So, if you don't warm up the oil to drive off the water vapour you get sulphuric acid and nitric acid buildup. Water and oil can also cause sludge. If you drive like this change the oil frequently.

[derric]

Originally Posted by Seattle S65B40

I have to re-arrange my car too and i sometimes roll it around in neutral so that I don't have to turn it on, or if I do, I will take it for a short drive to at least warm up a bit.

+1 just make sure you have some gloves plus it is a good work out for the legs, oh and don't do it yourself I had to replace a garage door/bumper one time because I couldn't hop back in fast enough.

Much better than the stress of a cold start/quick stop

[BPMSport]

I usually never do that unless I have to. Neutral and a good push if possible.

Always make sure it warms to operating temp. And people like to go by the coolant indicator, but keep in mind coolant warms much faster than oil!

I dented my M5 two years ago with my chin by pushing it back into the spot after washing the wheels. My chin hurt for over a week and I put a decent dent right by the emblem...

But yes, always make sure you drive the car to warm it up. Letting it sit idling is not good for it either!