I have an 04 Civic EX coupe, and specs say that oil capacity is 3.7 quarts. Got careless with a 5qt jug changing oil this time and might've added slightly over 4qt. How bad is this for the engine? Do I need to drain some to prevent damage, or will it be ok until the next oil change?
Also, the engine doesn't appear to be leaking or burning oil.
Thanks!
When you overfill the engine with too much oil you create 'Windage" which churns the oil and makes it into a milkshake...That milkshake has minute air bubbles so when it enters the oil pump the oil cannot lubricate the engine as intended...the air will compress so that metal surfaces will touch and cause wear. Your remedy. Drain the oil and measure out 4 quarts to refillagain. Or messy but quick is to drain the oil momentarily then put the drain plug back in. Check your dip stick...
Is it over the high mark on the dip stick? If so drain a little and slip the plug back on. You'll get your hands dirty but your oil seals will thank you.
A little over the full mark is no big deal. Look at the distance between low and full on the dipstick...that is usually a quart. Half that distance overfull isn't an issue...more than that, drain a little.
Well, I must disagree with this... some cars this is not acceptable at all and can cause harm... so in general I wouldn't give this advice.
I agree with @hillbilly too because filling up your oil to the MAX line (not necessarily synonymous to full) is already cutting it close. Think of the zone between the MIN and MAX as the "safe zone". Having the oil level at MIN means it is just enough for the oil pump strainer, and MAX means the oil is just about to make significant contact with the crankshaft (which we already discussed why that's bad). I always like to fill up more than halfway between MIN and MAX.
I'm sure engineers wouldn't design it so that 100mL above the max line damages the engine. You have to incorporate a margin to account for things like sloshing etc.
Just measure on the dipstick while on flat ground. If it is way over then you can drain some from the drain plug at the bottom or use a syringe with a tube to take a small amount off the top.
like this one:
Went ahead and loosened the plug and drained the overage. Not worth the risk leaving it too full. Didn't want to drag the floor jack out and hoped it wouldn't be an issue, but best to be safe. Feeling lazy and didn't want to fool with it 😉
Tried to pump out the overage with a couple of my hand pumps, but one's line was too thick for the dipstick hole, and the other's line was too short to get deep enough into the block to get to the oil.
Too much is worse than than a little low. You risk blowing the main seals which is an expensive mistake. I would just redo your oil change completely and this time, actually measure what you are putting in.
how does a main seal blow? I thought that crankcase pressure is regulated by the PCV valve.
It's not regulated by the PCV valve, it is relieved by the PCV valve, and another breather tube generally running from the valve cover to the air cleaner. Most people never think about the PCV valve but it should be cleaned or replaced at every oil change. Excessive amounts of oil create pressures beyond the ability of PCV vales and breathers to recirculate the vapors back into the combustion chamber.
oh ok, I though relieving pressure was way to keep it within a certain range. like a regulating valve if you will. In fact I think I think the PCV valve works in both directions.
It does not. It only works in one direction.
I see. So when the engine backfires, the PCV valve just vents all that pressure into the crankcase?
@mountainmanjoe @doc
First off, overfilling on oil does not necessarily cause significant crankcase pressure to the point where seals blow. Overfilling oil is bad MAINLY because it hinders engine lubrication. The PCV valve regulates the crankcase pressure caused by BLOW-BY gases, not necessarily from oil vapors. The PCV system is only one-way, meaning it only vents out crankcase pressure when it reaches the threshold for the valve spring to open. There is no "regulating" involved with the PCV valve; it only releases excess pressure and does not maintain a certain crankcase pressure. In fact, you don't want any pressure in the crankcase.
@razmig
You just said _excess_ pressure and "above a threshold". As usual , you contradict yourself with every sentence.
Look up how pressure regulator works. It's just a valve on spring. And PCV valves have not one but two sealing surfaces because they are bidirectional.
Razmig, again, please stop starting drama. I warned you before, and I will keep deleting it.
put a low plastic straw from windex can with spray nozel and siphon out
