Cold weather oil change - PeachParts Mercedes-Benz Forum

prityhandychick · #1 02-07-2011, 12:15 AM

Ok, I know that got a lot of your attention! I know to change it hot, but how hot? the car has been sitting since all the horrid weather started(been parked & not started for 6 days). '83 240D

I had the oil & filter & was ready to change it the day after I parked it & didn't have ANY idea that storm was headed here until too late to get it changed that day. So, the car is still snowed in and I can't get out yet. I have a long drive later this week and want to change the oil tomorrow (best day before I have to leave). If I leave the car running in the driveway, right where it is how long will I need to leave it running b/f I should change the oil?

bustedbenz · #2 02-07-2011, 12:32 AM

15 minutes. Main idea is just to get it stirred up and flowing easier. You don't want to run a sitting car for a shorter time than that because it allows moisture to condense in the oil (which is being changed) and the exhaust (which will rust). I'd idle it until it's at least up to 50-65C on the water temp gauge and then shut it off whenever you feel like after that.

gastropodus · #3 02-07-2011, 12:34 AM

These engines don't really heat up quickly if you're just idling. You can speed things up quite a bit by manually holding the throttle pedal down at about 1/4 or 1/3 travel; what I've noticed is that if I do this, after a minute or two of holding the pedal steady the RPM goes up steadily and smoothly. To me this indicates that the engine is starting to get decently warmed up. In your case I would go a few minutes (2-3) beyond that point, and then figure you're good to go (or good to drain, as it were).

Another way you might judge it is by pulling the dipstick, and feeling how warm the end is where it sits in the oil. It should feel decently warm to get good/low enough viscosity to flow out of the oil pan.

Kurt

bustedbenz · #4 02-07-2011, 12:44 AM

240 has a fast idle knob. Assuming it's adjusted properly, my personal $0.02 is that fast-idling uses marginally less fuel than manual 1/3 pedaling, and still warms the car at roughly (not exactly but close enough) to the same rate -- and doesn't require a leg cramp.

it's ENTIRELY personal choice however. If you want to sit in there holding it, there's sure nothing wrong with it and I don't mind a bit. For me it's simplest to just set the fast idler, go inside, and come back out in 15 mins and observe that the temp gauge is not pegged on cold anymore.

6 one way, half a dozen the other.

strelnik · #5 02-07-2011, 06:30 AM

Quote:

Originally Posted by bustedbenz

240 has a fast idle knob. Assuming it's adjusted properly, my personal $0.02 is that fast-idling uses marginally less fuel than manual 1/3 pedaling, and still warms the car at roughly (not exactly but close enough) to the same rate -- and doesn't require a leg cramp.

it's ENTIRELY personal choice however. If you want to sit in there holding it, there's sure nothing wrong with it and I don't mind a bit. For me it's simplest to just set the fast idler, go inside, and come back out in 15 mins and observe that the temp gauge is not pegged on cold anymore.

6 one way, half a dozen the other.

Go with the fast Idle knob. I do, if I am not using the block heater. If the engine is cold, your 240 will have heated up the oil at fast idle more than you need.

BTW despite the weather and the warm feeling a warm engine gives, be careful about burning yourself

prityhandychick · #6 02-07-2011, 10:41 AM

I'll be using the fast-idle...love that thing btw! Thanks!