I did an oil change. Thought the car took 4.4 quarts but it only takes 3.7 quarts. I poured in slightly under 4 quarts. The engine is a 1.5 in-line turbo (Honda Civic Si). It’s reading past the fill line slightly. How bad is it? Do I need to pour some out? What am I risking? What symptoms should I be looking for?
Automechanic for 10 years here.
No. A little over the max fill line on the dipstick isnt going to hurt it. 1/8 of an inch overfilled or less is okay.
Usually if you don’t prefill the oil filter and only add what they say then sometimes it can be a little under. Its not a big deal.
Way too much and you risk damaging piston rings or flooding, but you really have to fill it to the point its spilling from the dipstick tube.
My wife was a mechanic (lube tech) for a year or two when we were first dating. One guy came in after TOPPING OFF his oil with WATER and was complaining that it wasn’t running right
Its pretty unusual to have lube techs doing any diagnosis, but did she ask him if he likes chocolate milkshakes? Because That’s exactly what you create when you mix water in engine oil. Just don’t drink it.
Having once upon a time overfilled my oil by almost a quart, I think you are mostly right.
Engine oil should stay in the crankcase. During normal operation, some of it is pumped elsewhere to lubricate the crankshaft, cams, and other mechanical components. The rest of the oil sloshes and splashes around the crankcase keeping everything slippery. If there is too much excess in the crankcase, components moving can push the oil somewhere it shouldn’t be.
In my case, when turning left, the excess oil was pushed passed the piston rings and burned in a huge cloud of blue smoke. It wasn’t a proud moment, but stopping in a random service station and having Bruce try to drain a quart of oil out of the engine, because I couldn’t afford a full oil change was awkward.
… Anyway: all of that to say this:
If you have too little, your oil pressure light will probably come on. If you have too much, you’ll notice it somewhere else.
If you find yourself overfilling often, or if you are in the business and do heavy line work like I did (engine/transmission replacements and overhauls), just save yourself the time and get a fluid evacuator. If you overfill something you can pump a bit back out, they make them with pneumatic attachments or with a handpump that looks a bit like a bicycle tire air pump. Shove the little feed tube down the dipstick and pump whatever you need to back out.
EDIT: Fluid Evacuator
we’re supposed to pour it onto the oil filter too?
I mean, you don’t HAVE to. But you can pour some oil into the filter to pre-fill it so the oil doesn’t have to pump so long for the air you cycle out of the system, but the amount of time that happens for is so small it basically doesn’t matter. If the oil filter is easy to access and faces upward (the solid part faces the floor and open part faces up) then I would do it, but I wouldn’t do it in any other circumstance just to not have oil spilling and making a mess everywhere.
Youre not going to blow up the engine if you don’t. But it gives some people better peace of mind.
I just don’t pil change, it might show a little high, then you run the motor to cycle it through the system then it levels out. Good enough. A little less or extra doesn’t hurt anything.
Source: not a mechanic, but I know a lot of them and I’ve never taken my personal vehicle in for a change in 25 years.
LOL
*Old man knowledge here, not a professional mechanic. *
It’s fine.
Close enough!
Edit for a recommendation to OP: if you plan to change the oil in the same car for the foreseeable future – get a transparent plastic pitcher and add a fill line mark for the oil on the outside with nail polish, in your case 3.7 quarts. I do this with my car and makes for a no brainier oil change.
If you also do this for the container you drain old oil into, you will be able to see if your car is starting to shown signs of oil consumption issues.
E.g. if you know you fill with 3.7qt, and you drain less than 3.7qt, you know you need to start checking the oil level every few fillups.
Generally a great idea. On this particular motor you’re more likely to find EXTRA volume as it has a known issue of gasoline flowing past the rings and actually increasing the volume of liquid in the crankcase.
That… seems… bad… but what do I know
There are rumors of a class action lawsuit.
You will be ok. Over filling will not do anything other than make seals break easier. Oil circulates throughout the block all the time. A tiny bit more or short will not effect any long term performance.
I have worked on cars my whole life and I am a logistics manager for a fleet of commercial vehicles.
I put a whole extra quart into my Camry, you’ll be fine lol
If you had got it changed by a professional, they would have simply poured in all four quarts. You didn’t hurt a thing.
I usually fill mine right to the top and it hasn’t hurt the last sixteen cars I’ve had.
This guy oils.
It sounds like you’re going through cars a lot faster than average. Are you sure it didn’t hurt them?
Hi Dave.
Oil is good, more oil is gooder.
Ah, I hadn’t considered that! I normally apply that logic to my food but now I feel dumb for not realising it applies to everything!
When it’s still somewhat reasonable “too much”, as opposed to flooding the entire engine block with oil, the worst case scenario is that the piston rings get damaged, resulting in small amounts of oil making its way into the combustion chamber and gets burned off. Long term effects of this is that the engine consumes a little bit of oil.
In your case, I think you’ll be fine. It’s so little over, that I wouldn’t worry about it. You might see the engine burn off some oil and eventually stabilize on a more healthy level. Check the dip stick or whatever it’s called in English regularly, and see if it decreases (slowly) to the correct level.
Not decreasing: It’s fine
Decreasing and stabilizing: Best case scenario
Decreasing and doesn’t stabilize (not likely): Damaged piston rings. Slightly reduced engine performance, and your car has an mpg for oil now. Otherwise it’s fine. It’s worth noting that damaged piston rings is common in old cars, and it may have been like this from before.Source: I am no expert, so take what I say with a bucket of salt. I did experience the last scenario myself about 15 years ago. I still drive it with no long term effects.
🚗
I wouldn’t worry about it. Even on brand new cars, there are plenty where losing (burning) a quart of oil between changes is “within specifications.” The engine is likely going to burn a little bit of oil just because, and you’ll be lower again soon enough.
The danger is the crankshaft will hit the oil and foam up. Start the engine run at some rpm for a minute then check for foam at the dipstick if okay do a test drive with sharp corners and check again - if no foam you are okay. If ther is foam drain some out and then let the engine / foam settle overnight before driving.
This is the way.
(I’ll just note that oil with bubbles in it does not look like an actual milkshake. If it looks like a milkshake, then bad things are happening.)
