In my typical week, I use my 07 Honda Accord V6 Monday through Friday. On these days, the car is started up in cold weather (30 F), but I drive it for more than a hour, so I would assume any water vapor is burned off by then.

However, on Saturdays and Sundays, the car sits unused. Then maybe every 2 months or so, the car sits unused for a week or so.

Are these periods of un-use very bad for the car? I would assume that a lot of the oil would settle to the bottom of the oil pan and thus the engine may no longer be properly coated with oil when started up again?

To possibly help with this, I only use Mobil 1 5w-20, but not sure if that makes a difference at all. On the day that I start the car back up after sitting for 2-7 days, the idle rev is noticeable higher at the start of the car (it hits almost 1.5K RPM) but eventually goes down to the normal 650 rpm after 3-5 minutes.

Thanks for any advice or opinions!!!


Edit: One more question!!
From reading these forums, the general consensus on startup idling seems to be to start the car, wait about 30 seconds, then drive off gently until the car is warmed up.

This is what I do, but for the initial 30 seconds of idling, is it better to idle with the car in Park or in Neutral? I figure if the car is in Neutral, the engine is disconnected from the transmission and idles more "freely". Bad idea? Good idea? (the car is safely on a flat surface with no surrounding objects for a long distance, so the car isn't going to roll somewhere in neutral).

As you can see, I'm a novice with cars, so please forgive my gazillion questions! Thanks!!!

 

except for the acid buildup in the oil, i would imaging letting it sit for 10 hours or so would drain about as much oil out of the block as letting it sit for a few days.
though im in no way an expert on this...

 

IMO a week of doing nothing won't be an issue. Some oil (a light film) will cling to the working surfaces for a very long time, and that's all you need at initial start up, so long as the oil pressure light goes out very quickly as the engine fires. If it were siting idle for a month it might start being a concern.

I don't knmow why the car would idle higher on start up after being left a week compared to overnight. 1500rpm isn't an unusually high cold idle. How long is eventually? If it's only a couple of seconds or so (a short 'eventually'!) it could be that over the week that oil has drained out of the oil filter (possibly the filter's non return valve has a slight leak?), and as a result for a few seconds the pump is lazily refilling the filter instead of pumping against pressure? This would mean a lesser load on the engine until the pump fills the filter and starts to see some pressure, but I'd be surprised if this were enough to make a noticable difference to idle rpm(?).

It's better to idle the car in park than neutral, but it's only a safety concern,the engine itself doesn't know (or care) what gear the transmission is in.

 

the engine is connected to the same things in park as neutral, its the wheel side of the trans. that gets altered in park. i would say park then.

the high idle when the engine is cold is normal. Mine gets to ~1700 rpm when its cold outside. (wisconsin winters)
If i have the heat on full blast with the engine fully warmed up and im sitting at a stoplight, my temp gauge will go down!

I wouldnt worry about it.

 

talk about paranoid.... [8D]

park and neutral have the same load on the engine.

like said, oil will cling to the metal a very long time. i have cylinder heads from years ago not taken apart, but when i need a valve or part from an old head and dismantle it, it's still clean and fresh inside, oily. if you are really concerend about it use a VERY high quality oil additive(i highly recommend BG MOA, it contains additives similar to the original break-in oil and cost about $5-$10 on ebay)